Checkpoint

Co-Authored-By: Bennet <bennet@zed.dev>
Co-Authored-By: Thorsten <thorsten@zed.dev>

Cargo.lock

@@ -15565,6 +15565,7 @@ dependencies = [
  "winresource",
  "workspace",
  "zed_actions",
+ "zeta",
 ]
 
 [[package]]
@@ -15875,6 +15876,30 @@ dependencies = [
  "syn 2.0.87",
 ]
 
+[[package]]
+name = "zeta"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "collections",
+ "ctor",
+ "env_logger 0.11.5",
+ "futures 0.3.31",
+ "gpui",
+ "http_client",
+ "indoc",
+ "inline_completion",
+ "language",
+ "log",
+ "open_ai",
+ "reqwest_client",
+ "rpc",
+ "similar",
+ "tree-sitter-go",
+ "tree-sitter-rust",
+ "worktree",
+]
+
 [[package]]
 name = "zstd"
 version = "0.11.2+zstd.1.5.2"

Cargo.toml

@@ -133,6 +133,7 @@ members = [
     "crates/worktree",
     "crates/zed",
     "crates/zed_actions",
+    "crates/zeta",
 
     #
     # Extensions
@@ -307,6 +308,7 @@ workspace = { path = "crates/workspace" }
 worktree = { path = "crates/worktree" }
 zed = { path = "crates/zed" }
 zed_actions = { path = "crates/zed_actions" }
+zeta = { path = "crates/zeta" }
 
 #
 # External crates

crates/editor/src/editor.rs

@@ -5304,7 +5304,8 @@ impl Editor {
 
         if !user_requested
             && (!self.enable_inline_completions
-                || !self.should_show_inline_completions(&buffer, cursor_buffer_position, cx))
+                || !self.should_show_inline_completions(&buffer, cursor_buffer_position, cx)
+                || !self.is_focused(cx))
         {
             self.discard_inline_completion(false, cx);
             return None;

crates/inline_completion_button/src/inline_completion_button.rs

@@ -193,6 +193,8 @@ impl Render for InlineCompletionButton {
                         ),
                 );
             }
+
+            InlineCompletionProvider::Zeta => div().child("Zeta"),
         }
     }
 }

crates/language/src/buffer.rs

@@ -575,7 +575,7 @@ impl<'a, 'b> DerefMut for ChunkRendererContext<'a, 'b> {
 pub struct Diff {
     pub(crate) base_version: clock::Global,
     line_ending: LineEnding,
-    edits: Vec<(Range<usize>, Arc<str>)>,
+    pub edits: Vec<(Range<usize>, Arc<str>)>,
 }
 
 #[derive(Clone, Copy)]

crates/language/src/language_settings.rs

@@ -197,6 +197,7 @@ pub enum InlineCompletionProvider {
     #[default]
     Copilot,
     Supermaven,
+    Zeta,
 }
 
 /// The settings for inline completions, such as [GitHub Copilot](https://github.com/features/copilot)

crates/language_model/src/request.rs

@@ -266,6 +266,7 @@ impl LanguageModelRequest {
             max_tokens: max_output_tokens,
             tools: Vec::new(),
             tool_choice: None,
+            prediction: None,
         }
     }
 

crates/open_ai/src/open_ai.rs

@@ -164,11 +164,19 @@ pub struct Request {
     pub stop: Vec<String>,
     pub temperature: f32,
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub prediction: Option<Prediction>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
     pub tool_choice: Option<ToolChoice>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub tools: Vec<ToolDefinition>,
 }
 
+#[derive(Clone, Deserialize, Serialize, Debug)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum Prediction {
+    Content { content: String },
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(untagged)]
 pub enum ToolChoice {
@@ -285,6 +293,21 @@ pub struct ResponseStreamEvent {
     pub usage: Option<Usage>,
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+pub struct CompletionResponse {
+    pub id: String,
+    pub object: String,
+    pub created: u64,
+    pub model: String,
+    pub choices: Vec<CompletionChoice>,
+    pub usage: Usage,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct CompletionChoice {
+    pub text: String,
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Response {
     pub id: String,
@@ -355,6 +378,66 @@ pub async fn complete(
     }
 }
 
+pub async fn complete_text(
+    client: &dyn HttpClient,
+    api_url: &str,
+    api_key: &str,
+    prompt: &str,
+    model: &str,
+    max_tokens: Option<u32>,
+    temperature: f32,
+) -> Result<CompletionResponse> {
+    let uri = format!("{api_url}/completions");
+    let request_builder = HttpRequest::builder()
+        .method(Method::POST)
+        .uri(uri)
+        .header("Content-Type", "application/json")
+        .header("Authorization", format!("Bearer {}", api_key));
+
+    let request_body = serde_json::json!({
+        "model": model,
+        "prompt": prompt,
+        "max_tokens": max_tokens,
+        "temperature": temperature
+    });
+
+    let request = request_builder.body(AsyncBody::from(request_body.to_string()))?;
+    let mut response = client.send(request).await?;
+
+    if response.status().is_success() {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+        let response = serde_json::from_str(&body)?;
+        Ok(response)
+    } else {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+
+        #[derive(Deserialize)]
+        struct OpenAiResponse {
+            error: OpenAiError,
+        }
+
+        #[derive(Deserialize)]
+        struct OpenAiError {
+            message: String,
+        }
+
+        match serde_json::from_str::<OpenAiResponse>(&body) {
+            Ok(response) if !response.error.message.is_empty() => Err(anyhow!(
+                "Failed to connect to OpenAI API: {}",
+                response.error.message,
+            )),
+
+            _ => Err(anyhow!(
+                "Failed to connect to OpenAI API: {} {}",
+                response.status(),
+                body,
+            )),
+        }
+    }
+}
+
 fn adapt_response_to_stream(response: Response) -> ResponseStreamEvent {
     ResponseStreamEvent {
         created: response.created as u32,

crates/vim/src/vim.rs

@@ -1104,6 +1104,15 @@ impl Vim {
                 if self.mode == Mode::Replace {
                     self.multi_replace(text, cx)
                 }
+
+                if self.mode == Mode::Normal {
+                    self.update_editor(cx, |_, editor, cx| {
+                        editor.accept_inline_completion(
+                            &editor::actions::AcceptInlineCompletion {},
+                            cx,
+                        );
+                    });
+                }
             }
         }
     }

crates/zed/Cargo.toml

@@ -120,6 +120,7 @@ vim.workspace = true
 welcome.workspace = true
 workspace.workspace = true
 zed_actions.workspace = true
+zeta.workspace = true
 
 [target.'cfg(target_os = "windows")'.dependencies]
 windows.workspace = true

crates/zed/src/zed/inline_completion_registry.rs

@@ -131,5 +131,17 @@ fn assign_inline_completion_provider(
                 editor.set_inline_completion_provider(Some(provider), cx);
             }
         }
+        language::language_settings::InlineCompletionProvider::Zeta => {
+            let zeta = zeta::Zeta::global(cx);
+            if let Some(buffer) = editor.buffer().read(cx).as_singleton() {
+                if buffer.read(cx).file().is_some() {
+                    zeta.update(cx, |zeta, cx| {
+                        zeta.register_buffer(&buffer, cx);
+                    });
+                }
+            }
+            let provider = cx.new_model(|_| zeta::ZetaInlineCompletionProvider::new(zeta));
+            editor.set_inline_completion_provider(Some(provider), cx);
+        }
     }
 }

crates/zeta/Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name = "zeta"
+version = "0.1.0"
+edition = "2021"
+publish = false
+license = "GPL-3.0-or-later"
+exclude = ["fixtures"]
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/zeta.rs"
+doctest = false
+
+[dependencies]
+anyhow.workspace = true
+collections.workspace = true
+futures.workspace = true
+gpui.workspace = true
+http_client.workspace = true
+inline_completion.workspace = true
+language.workspace = true
+log.workspace = true
+open_ai.workspace = true
+similar.workspace = true
+
+[dev-dependencies]
+collections = { workspace = true, features = ["test-support"] }
+ctor.workspace = true
+env_logger.workspace = true
+gpui = { workspace = true, features = ["test-support"] }
+http_client = { workspace = true, features = ["test-support"] }
+indoc.workspace = true
+language = { workspace = true, features = ["test-support"] }
+reqwest_client = { workspace = true, features = ["test-support"] }
+rpc = { workspace = true, features = ["test-support"] }
+tree-sitter-go.workspace = true
+tree-sitter-rust.workspace = true
+worktree = { workspace = true, features = ["test-support"] }

crates/zeta/fixtures/interpreter/ast_edit1.go

@@ -0,0 +1,375 @@
+package ast
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	"github.com/mrnugget/monkey/token"
+)
+
+// The base Node interface
+type Node interface {
+	TokenLiteral() string
+	String() string
+}
+
+// All statement nodes implement this
+type Statement interface {
+	Node
+	statementNode()
+}
+
+// All expression nodes implement this
+type Expression interface {
+	Node
+	expressionNode()
+}
+
+type Program struct {
+	Statements []Statement
+}
+
+func (p *Program) TokenLiteral() string {
+	if len(p.Statements) > 0 {
+		return p.Statements[0].TokenLiteral()
+	} else {
+		return ""
+	}
+}
+
+func (p *Program) String() string {
+	var out bytes.Buffer
+
+	for _, s := range p.Statements {
+		out.WriteString(s.String())
+	}
+
+	return out.String()
+}
+
+// Statements
+type WhileStatement struct {
+    <|user_cursor_is_here|>
+}
+type LetStatement struct {
+	Token token.Token // the token.LET token
+	Name  *Identifier
+	Value Expression
+}
+
+func (ls *LetStatement) statementNode()       {}
+func (ls *LetStatement) TokenLiteral() string { return ls.Token.Literal }
+func (ls *LetStatement) String() string {
+	var out bytes.Buffer
+
+	out.WriteString(ls.TokenLiteral() + " ")
+	out.WriteString(ls.Name.String())
+	out.WriteString(" = ")
+
+	if ls.Value != nil {
+		out.WriteString(ls.Value.String())
+	}
+
+	out.WriteString(";")
+
+	return out.String()
+}
+
+type ReturnStatement struct {
+	Token       token.Token // the 'return' token
+	ReturnValue Expression
+}
+
+func (rs *ReturnStatement) statementNode()       {}
+func (rs *ReturnStatement) TokenLiteral() string { return rs.Token.Literal }
+func (rs *ReturnStatement) String() string {
+	var out bytes.Buffer
+
+	out.WriteString(rs.TokenLiteral() + " ")
+
+	if rs.ReturnValue != nil {
+		out.WriteString(rs.ReturnValue.String())
+	}
+
+	out.WriteString(";")
+
+	return out.String()
+}
+
+type ExpressionStatement struct {
+	Token      token.Token // the first token of the expression
+	Expression Expression
+}
+
+func (es *ExpressionStatement) statementNode()       {}
+func (es *ExpressionStatement) TokenLiteral() string { return es.Token.Literal }
+func (es *ExpressionStatement) String() string {
+	if es.Expression != nil {
+		return es.Expression.String()
+	}
+	return ""
+}
+
+type BlockStatement struct {
+	Token      token.Token // the { token
+	Statements []Statement
+}
+
+func (bs *BlockStatement) statementNode()       {}
+func (bs *BlockStatement) TokenLiteral() string { return bs.Token.Literal }
+func (bs *BlockStatement) String() string {
+	var out bytes.Buffer
+
+	for _, s := range bs.Statements {
+		out.WriteString(s.String())
+	}
+
+	return out.String()
+}
+
+// Expressions
+type Identifier struct {
+	Token token.Token // the token.IDENT token
+	Value string
+}
+
+func (i *Identifier) expressionNode()      {}
+func (i *Identifier) TokenLiteral() string { return i.Token.Literal }
+func (i *Identifier) String() string       { return i.Value }
+
+type Boolean struct {
+	Token token.Token
+	Value bool
+}
+
+func (b *Boolean) expressionNode()      {}
+func (b *Boolean) TokenLiteral() string { return b.Token.Literal }
+func (b *Boolean) String() string       { return b.Token.Literal }
+
+type IntegerLiteral struct {
+	Token token.Token
+	Value int64
+}
+
+func (il *IntegerLiteral) expressionNode()      {}
+func (il *IntegerLiteral) TokenLiteral() string { return il.Token.Literal }
+func (il *IntegerLiteral) String() string       { return il.Token.Literal }
+
+type PrefixExpression struct {
+	Token    token.Token // The prefix token, e.g. !
+	Operator string
+	Right    Expression
+}
+
+func (pe *PrefixExpression) expressionNode()      {}
+func (pe *PrefixExpression) TokenLiteral() string { return pe.Token.Literal }
+func (pe *PrefixExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(pe.Operator)
+	out.WriteString(pe.Right.String())
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type InfixExpression struct {
+	Token    token.Token // The operator token, e.g. +
+	Left     Expression
+	Operator string
+	Right    Expression
+}
+
+func (oe *InfixExpression) expressionNode()      {}
+func (oe *InfixExpression) TokenLiteral() string { return oe.Token.Literal }
+func (oe *InfixExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(oe.Left.String())
+	out.WriteString(" " + oe.Operator + " ")
+	out.WriteString(oe.Right.String())
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type IfExpression struct {
+	Token       token.Token // The 'if' token
+	Condition   Expression
+	Consequence *BlockStatement
+	Alternative *BlockStatement
+}
+
+func (ie *IfExpression) expressionNode()      {}
+func (ie *IfExpression) TokenLiteral() string { return ie.Token.Literal }
+func (ie *IfExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("if (")
+	out.WriteString(ie.Condition.String())
+	out.WriteString(") { ")
+	out.WriteString(ie.Consequence.String())
+	out.WriteString(" }")
+
+	if ie.Alternative != nil {
+		out.WriteString(" else { ")
+		out.WriteString(ie.Alternative.String())
+		out.WriteString(" }")
+	}
+
+	return out.String()
+}
+
+type FunctionLiteral struct {
+	Token      token.Token // The 'fn' token
+	Parameters []*Identifier
+	Body       *BlockStatement
+	Name       string
+}
+
+func (fl *FunctionLiteral) expressionNode()      {}
+func (fl *FunctionLiteral) TokenLiteral() string { return fl.Token.Literal }
+func (fl *FunctionLiteral) String() string {
+	var out bytes.Buffer
+
+	params := []string{}
+	for _, p := range fl.Parameters {
+		params = append(params, p.String())
+	}
+
+	out.WriteString(fl.TokenLiteral())
+	if fl.Name != "" {
+		out.WriteString(fmt.Sprintf("<%s>", fl.Name))
+	}
+	out.WriteString("(")
+	out.WriteString(strings.Join(params, ", "))
+	out.WriteString(") ")
+	out.WriteString(fl.Body.String())
+
+	return out.String()
+}
+
+type CallExpression struct {
+	Token     token.Token // The '(' token
+	Function  Expression  // Identifier or FunctionLiteral
+	Arguments []Expression
+}
+
+func (ce *CallExpression) expressionNode()      {}
+func (ce *CallExpression) TokenLiteral() string { return ce.Token.Literal }
+func (ce *CallExpression) String() string {
+	var out bytes.Buffer
+
+	args := []string{}
+	for _, a := range ce.Arguments {
+		args = append(args, a.String())
+	}
+
+	out.WriteString(ce.Function.String())
+	out.WriteString("(")
+	out.WriteString(strings.Join(args, ", "))
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type StringLiteral struct {
+	Token token.Token
+	Value string
+}
+
+func (sl *StringLiteral) expressionNode()      {}
+func (sl *StringLiteral) TokenLiteral() string { return sl.Token.Literal }
+func (sl *StringLiteral) String() string       { return sl.Token.Literal }
+
+type ArrayLiteral struct {
+	Token    token.Token // the '[' token
+	Elements []Expression
+}
+
+func (al *ArrayLiteral) expressionNode()      {}
+func (al *ArrayLiteral) TokenLiteral() string { return al.Token.Literal }
+func (al *ArrayLiteral) String() string {
+	var out bytes.Buffer
+
+	elements := []string{}
+	for _, el := range al.Elements {
+		elements = append(elements, el.String())
+	}
+
+	out.WriteString("[")
+	out.WriteString(strings.Join(elements, ", "))
+	out.WriteString("]")
+
+	return out.String()
+}
+
+type IndexExpression struct {
+	Token token.Token // The [ token
+	Left  Expression
+	Index Expression
+}
+
+func (ie *IndexExpression) expressionNode()      {}
+func (ie *IndexExpression) TokenLiteral() string { return ie.Token.Literal }
+func (ie *IndexExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(ie.Left.String())
+	out.WriteString("[")
+	out.WriteString(ie.Index.String())
+	out.WriteString("])")
+
+	return out.String()
+}
+
+type HashLiteral struct {
+	Token token.Token // the '{' token
+	Pairs map[Expression]Expression
+}
+
+func (hl *HashLiteral) expressionNode()      {}
+func (hl *HashLiteral) TokenLiteral() string { return hl.Token.Literal }
+func (hl *HashLiteral) String() string {
+	var out bytes.Buffer
+
+	pairs := []string{}
+	for key, value := range hl.Pairs {
+		pairs = append(pairs, key.String()+":"+value.String())
+	}
+
+	out.WriteString("{")
+	out.WriteString(strings.Join(pairs, ", "))
+	out.WriteString("}")
+
+	return out.String()
+}
+
+type MacroLiteral struct {
+	Token      token.Token // The 'macro' token
+	Parameters []*Identifier
+	Body       *BlockStatement
+}
+
+func (ml *MacroLiteral) expressionNode()      {}
+func (ml *MacroLiteral) TokenLiteral() string { return ml.Token.Literal }
+func (ml *MacroLiteral) String() string {
+	var out bytes.Buffer
+
+	params := []string{}
+	for _, p := range ml.Parameters {
+		params = append(params, p.String())
+	}
+
+	out.WriteString(ml.TokenLiteral())
+	out.WriteString("(")
+	out.WriteString(strings.Join(params, ", "))
+	out.WriteString(") ")
+	out.WriteString(ml.Body.String())
+
+	return out.String()
+}

crates/zeta/fixtures/interpreter/ast_initial.go

@@ -0,0 +1,372 @@
+package ast
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	"github.com/mrnugget/monkey/token"
+)
+
+// The base Node interface
+type Node interface {
+	TokenLiteral() string
+	String() string
+}
+
+// All statement nodes implement this
+type Statement interface {
+	Node
+	statementNode()
+}
+
+// All expression nodes implement this
+type Expression interface {
+	Node
+	expressionNode()
+}
+
+type Program struct {
+	Statements []Statement
+}
+
+func (p *Program) TokenLiteral() string {
+	if len(p.Statements) > 0 {
+		return p.Statements[0].TokenLiteral()
+	} else {
+		return ""
+	}
+}
+
+func (p *Program) String() string {
+	var out bytes.Buffer
+
+	for _, s := range p.Statements {
+		out.WriteString(s.String())
+	}
+
+	return out.String()
+}
+
+// Statements
+type LetStatement struct {
+	Token token.Token // the token.LET token
+	Name  *Identifier
+	Value Expression
+}
+
+func (ls *LetStatement) statementNode()       {}
+func (ls *LetStatement) TokenLiteral() string { return ls.Token.Literal }
+func (ls *LetStatement) String() string {
+	var out bytes.Buffer
+
+	out.WriteString(ls.TokenLiteral() + " ")
+	out.WriteString(ls.Name.String())
+	out.WriteString(" = ")
+
+	if ls.Value != nil {
+		out.WriteString(ls.Value.String())
+	}
+
+	out.WriteString(";")
+
+	return out.String()
+}
+
+type ReturnStatement struct {
+	Token       token.Token // the 'return' token
+	ReturnValue Expression
+}
+
+func (rs *ReturnStatement) statementNode()       {}
+func (rs *ReturnStatement) TokenLiteral() string { return rs.Token.Literal }
+func (rs *ReturnStatement) String() string {
+	var out bytes.Buffer
+
+	out.WriteString(rs.TokenLiteral() + " ")
+
+	if rs.ReturnValue != nil {
+		out.WriteString(rs.ReturnValue.String())
+	}
+
+	out.WriteString(";")
+
+	return out.String()
+}
+
+type ExpressionStatement struct {
+	Token      token.Token // the first token of the expression
+	Expression Expression
+}
+
+func (es *ExpressionStatement) statementNode()       {}
+func (es *ExpressionStatement) TokenLiteral() string { return es.Token.Literal }
+func (es *ExpressionStatement) String() string {
+	if es.Expression != nil {
+		return es.Expression.String()
+	}
+	return ""
+}
+
+type BlockStatement struct {
+	Token      token.Token // the { token
+	Statements []Statement
+}
+
+func (bs *BlockStatement) statementNode()       {}
+func (bs *BlockStatement) TokenLiteral() string { return bs.Token.Literal }
+func (bs *BlockStatement) String() string {
+	var out bytes.Buffer
+
+	for _, s := range bs.Statements {
+		out.WriteString(s.String())
+	}
+
+	return out.String()
+}
+
+// Expressions
+type Identifier struct {
+	Token token.Token // the token.IDENT token
+	Value string
+}
+
+func (i *Identifier) expressionNode()      {}
+func (i *Identifier) TokenLiteral() string { return i.Token.Literal }
+func (i *Identifier) String() string       { return i.Value }
+
+type Boolean struct {
+	Token token.Token
+	Value bool
+}
+
+func (b *Boolean) expressionNode()      {}
+func (b *Boolean) TokenLiteral() string { return b.Token.Literal }
+func (b *Boolean) String() string       { return b.Token.Literal }
+
+type IntegerLiteral struct {
+	Token token.Token
+	Value int64
+}
+
+func (il *IntegerLiteral) expressionNode()      {}
+func (il *IntegerLiteral) TokenLiteral() string { return il.Token.Literal }
+func (il *IntegerLiteral) String() string       { return il.Token.Literal }
+
+type PrefixExpression struct {
+	Token    token.Token // The prefix token, e.g. !
+	Operator string
+	Right    Expression
+}
+
+func (pe *PrefixExpression) expressionNode()      {}
+func (pe *PrefixExpression) TokenLiteral() string { return pe.Token.Literal }
+func (pe *PrefixExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(pe.Operator)
+	out.WriteString(pe.Right.String())
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type InfixExpression struct {
+	Token    token.Token // The operator token, e.g. +
+	Left     Expression
+	Operator string
+	Right    Expression
+}
+
+func (oe *InfixExpression) expressionNode()      {}
+func (oe *InfixExpression) TokenLiteral() string { return oe.Token.Literal }
+func (oe *InfixExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(oe.Left.String())
+	out.WriteString(" " + oe.Operator + " ")
+	out.WriteString(oe.Right.String())
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type IfExpression struct {
+	Token       token.Token // The 'if' token
+	Condition   Expression
+	Consequence *BlockStatement
+	Alternative *BlockStatement
+}
+
+func (ie *IfExpression) expressionNode()      {}
+func (ie *IfExpression) TokenLiteral() string { return ie.Token.Literal }
+func (ie *IfExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("if (")
+	out.WriteString(ie.Condition.String())
+	out.WriteString(") { ")
+	out.WriteString(ie.Consequence.String())
+	out.WriteString(" }")
+
+	if ie.Alternative != nil {
+		out.WriteString(" else { ")
+		out.WriteString(ie.Alternative.String())
+		out.WriteString(" }")
+	}
+
+	return out.String()
+}
+
+type FunctionLiteral struct {
+	Token      token.Token // The 'fn' token
+	Parameters []*Identifier
+	Body       *BlockStatement
+	Name       string
+}
+
+func (fl *FunctionLiteral) expressionNode()      {}
+func (fl *FunctionLiteral) TokenLiteral() string { return fl.Token.Literal }
+func (fl *FunctionLiteral) String() string {
+	var out bytes.Buffer
+
+	params := []string{}
+	for _, p := range fl.Parameters {
+		params = append(params, p.String())
+	}
+
+	out.WriteString(fl.TokenLiteral())
+	if fl.Name != "" {
+		out.WriteString(fmt.Sprintf("<%s>", fl.Name))
+	}
+	out.WriteString("(")
+	out.WriteString(strings.Join(params, ", "))
+	out.WriteString(") ")
+	out.WriteString(fl.Body.String())
+
+	return out.String()
+}
+
+type CallExpression struct {
+	Token     token.Token // The '(' token
+	Function  Expression  // Identifier or FunctionLiteral
+	Arguments []Expression
+}
+
+func (ce *CallExpression) expressionNode()      {}
+func (ce *CallExpression) TokenLiteral() string { return ce.Token.Literal }
+func (ce *CallExpression) String() string {
+	var out bytes.Buffer
+
+	args := []string{}
+	for _, a := range ce.Arguments {
+		args = append(args, a.String())
+	}
+
+	out.WriteString(ce.Function.String())
+	out.WriteString("(")
+	out.WriteString(strings.Join(args, ", "))
+	out.WriteString(")")
+
+	return out.String()
+}
+
+type StringLiteral struct {
+	Token token.Token
+	Value string
+}
+
+func (sl *StringLiteral) expressionNode()      {}
+func (sl *StringLiteral) TokenLiteral() string { return sl.Token.Literal }
+func (sl *StringLiteral) String() string       { return sl.Token.Literal }
+
+type ArrayLiteral struct {
+	Token    token.Token // the '[' token
+	Elements []Expression
+}
+
+func (al *ArrayLiteral) expressionNode()      {}
+func (al *ArrayLiteral) TokenLiteral() string { return al.Token.Literal }
+func (al *ArrayLiteral) String() string {
+	var out bytes.Buffer
+
+	elements := []string{}
+	for _, el := range al.Elements {
+		elements = append(elements, el.String())
+	}
+
+	out.WriteString("[")
+	out.WriteString(strings.Join(elements, ", "))
+	out.WriteString("]")
+
+	return out.String()
+}
+
+type IndexExpression struct {
+	Token token.Token // The [ token
+	Left  Expression
+	Index Expression
+}
+
+func (ie *IndexExpression) expressionNode()      {}
+func (ie *IndexExpression) TokenLiteral() string { return ie.Token.Literal }
+func (ie *IndexExpression) String() string {
+	var out bytes.Buffer
+
+	out.WriteString("(")
+	out.WriteString(ie.Left.String())
+	out.WriteString("[")
+	out.WriteString(ie.Index.String())
+	out.WriteString("])")
+
+	return out.String()
+}
+
+type HashLiteral struct {
+	Token token.Token // the '{' token
+	Pairs map[Expression]Expression
+}
+
+func (hl *HashLiteral) expressionNode()      {}
+func (hl *HashLiteral) TokenLiteral() string { return hl.Token.Literal }
+func (hl *HashLiteral) String() string {
+	var out bytes.Buffer
+
+	pairs := []string{}
+	for key, value := range hl.Pairs {
+		pairs = append(pairs, key.String()+":"+value.String())
+	}
+
+	out.WriteString("{")
+	out.WriteString(strings.Join(pairs, ", "))
+	out.WriteString("}")
+
+	return out.String()
+}
+
+type MacroLiteral struct {
+	Token      token.Token // The 'macro' token
+	Parameters []*Identifier
+	Body       *BlockStatement
+}
+
+func (ml *MacroLiteral) expressionNode()      {}
+func (ml *MacroLiteral) TokenLiteral() string { return ml.Token.Literal }
+func (ml *MacroLiteral) String() string {
+	var out bytes.Buffer
+
+	params := []string{}
+	for _, p := range ml.Parameters {
+		params = append(params, p.String())
+	}
+
+	out.WriteString(ml.TokenLiteral())
+	out.WriteString("(")
+	out.WriteString(strings.Join(params, ", "))
+	out.WriteString(") ")
+	out.WriteString(ml.Body.String())
+
+	return out.String()
+}

crates/zeta/fixtures/interpreter/token_edit1.go

@@ -0,0 +1,73 @@
+package token
+
+type TokenType string
+
+const (
+	ILLEGAL = "ILLEGAL"
+	EOF     = "EOF"
+
+	// Identifiers + literals
+	IDENT  = "IDENT"  // add, foobar, x, y, ...
+	INT    = "INT"    // 1343456
+	STRING = "STRING" // "foobar"
+
+	// Operators
+	ASSIGN   = "="
+	PLUS     = "+"
+	MINUS    = "-"
+	BANG     = "!"
+	ASTERISK = "*"
+	SLASH    = "/"
+
+	LT = "<"
+	GT = ">"
+
+	EQ     = "=="
+	NOT_EQ = "!="
+
+	// Delimiters
+	COMMA     = ","
+	SEMICOLON = ";"
+	COLON     = ":"
+
+	LPAREN   = "("
+	RPAREN   = ")"
+	LBRACE   = "{"
+	RBRACE   = "}"
+	LBRACKET = "["
+	RBRACKET = "]"
+
+	// Keywords
+	FUNCTION = "FUNCTION"
+	LET      = "LET"
+	TRUE     = "TRUE"
+	FALSE    = "FALSE"
+	IF       = "IF"
+	ELSE     = "ELSE"
+	RETURN   = "RETURN"
+	MACRO    = "MACRO"
+	WHILE <|user_cursor_is_here|>
+)
+
+type Token struct {
+	Type    TokenType
+	Literal string
+}
+
+var keywords = map[string]TokenType{
+	"fn":     FUNCTION,
+	"let":    LET,
+	"true":   TRUE,
+	"false":  FALSE,
+	"if":     IF,
+	"else":   ELSE,
+	"return": RETURN,
+	"macro":  MACRO,
+}
+
+func LookupIdent(ident string) TokenType {
+	if tok, ok := keywords[ident]; ok {
+		return tok
+	}
+	return IDENT
+}

crates/zeta/fixtures/interpreter/token_initial.go

@@ -0,0 +1,72 @@
+package token
+
+type TokenType string
+
+const (
+	ILLEGAL = "ILLEGAL"
+	EOF     = "EOF"
+
+	// Identifiers + literals
+	IDENT  = "IDENT"  // add, foobar, x, y, ...
+	INT    = "INT"    // 1343456
+	STRING = "STRING" // "foobar"
+
+	// Operators
+	ASSIGN   = "="
+	PLUS     = "+"
+	MINUS    = "-"
+	BANG     = "!"
+	ASTERISK = "*"
+	SLASH    = "/"
+
+	LT = "<"
+	GT = ">"
+
+	EQ     = "=="
+	NOT_EQ = "!="
+
+	// Delimiters
+	COMMA     = ","
+	SEMICOLON = ";"
+	COLON     = ":"
+
+	LPAREN   = "("
+	RPAREN   = ")"
+	LBRACE   = "{"
+	RBRACE   = "}"
+	LBRACKET = "["
+	RBRACKET = "]"
+
+	// Keywords
+	FUNCTION = "FUNCTION"
+	LET      = "LET"
+	TRUE     = "TRUE"
+	FALSE    = "FALSE"
+	IF       = "IF"
+	ELSE     = "ELSE"
+	RETURN   = "RETURN"
+	MACRO    = "MACRO"
+)
+
+type Token struct {
+	Type    TokenType
+	Literal string
+}
+
+var keywords = map[string]TokenType{
+	"fn":     FUNCTION,
+	"let":    LET,
+	"true":   TRUE,
+	"false":  FALSE,
+	"if":     IF,
+	"else":   ELSE,
+	"return": RETURN,
+	"macro":  MACRO,
+}
+
+func LookupIdent(ident string) TokenType {
+	if tok, ok := keywords[ident]; ok {
+		return tok
+	}
+	return IDENT
+}

crates/zeta/fixtures/new-cli-arg/edit1.rs

@@ -0,0 +1,709 @@
+#![cfg_attr(
+    any(target_os = "linux", target_os = "freebsd", target_os = "windows"),
+    allow(dead_code)
+)]
+
+use anyhow::{Context, Result};
+use clap::Parser;
+use cli::{ipc::IpcOneShotServer, CliRequest, CliResponse, IpcHandshake};
+use collections::HashMap;
+use parking_lot::Mutex;
+use std::{
+    env, fs, io,
+    path::{Path, PathBuf},
+    process::ExitStatus,
+    sync::Arc,
+    thread::{self, JoinHandle},
+};
+use tempfile::NamedTempFile;
+use util::paths::PathWithPosition;
+
+struct Detect;
+
+trait InstalledApp {
+    fn zed_version_string(&self) -> String;
+    fn launch(&self, ipc_url: String) -> anyhow::Result<()>;
+    fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus>;
+}
+
+#[derive(Parser, Debug)]
+#[command(
+    name = "zed",
+    disable_version_flag = true,
+    after_help = "To read from stdin, append '-' (e.g. 'ps axf | zed -')"
+)]
+struct Args {
+    /// Wait for all of the given paths to be opened/closed before exiting.
+    #[arg(short, long)]
+    wait: bool,
+    /// Add files to the currently open workspace
+    #[arg(short, long, overrides_with = "new")]
+    add: bool,
+    /// Create a new workspace
+    #[arg(short, long, overrides_with = "add")]
+    new: bool,
+    /// A sequence of space-separated paths that you want to open.
+    ///
+    /// Use `path:line:row` syntax to open a file at a specific location.
+    /// Non-existing paths and directories will ignore `:line:row` suffix.
+    paths_with_position: Vec<String>,
+    /// Print Zed's version and the app path.
+    #[arg(short, long)]
+    version: bool,
+    /// Run zed in the foreground (useful for debugging)
+    #[arg(long)]
+    foreground: bool,
+    /// Custom path to Zed.app or the zed binary
+    #[arg(long)]
+    zed: Option<PathBuf>,
+    /// Run zed in dev-server mode
+    #[arg(long)]
+    dev_server_token: Option<String>,
+    /// Only update the Zed instance
+    <|user_cursor_is_here|>
+}
+
+fn parse_path_with_position(argument_str: &str) -> anyhow::Result<String> {
+    let canonicalized = match Path::new(argument_str).canonicalize() {
+        Ok(existing_path) => PathWithPosition::from_path(existing_path),
+        Err(_) => {
+            let path = PathWithPosition::parse_str(argument_str);
+            let curdir = env::current_dir().context("reteiving current directory")?;
+            path.map_path(|path| match fs::canonicalize(&path) {
+                Ok(path) => Ok(path),
+                Err(e) => {
+                    if let Some(mut parent) = path.parent() {
+                        if parent == Path::new("") {
+                            parent = &curdir
+                        }
+                        match fs::canonicalize(parent) {
+                            Ok(parent) => Ok(parent.join(path.file_name().unwrap())),
+                            Err(_) => Err(e),
+                        }
+                    } else {
+                        Err(e)
+                    }
+                }
+            })
+        }
+        .with_context(|| format!("parsing as path with position {argument_str}"))?,
+    };
+    Ok(canonicalized.to_string(|path| path.to_string_lossy().to_string()))
+}
+
+fn main() -> Result<()> {
+    // Exit flatpak sandbox if needed
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    {
+        flatpak::try_restart_to_host();
+        flatpak::ld_extra_libs();
+    }
+
+    // Intercept version designators
+    #[cfg(target_os = "macos")]
+    if let Some(channel) = std::env::args().nth(1).filter(|arg| arg.starts_with("--")) {
+        // When the first argument is a name of a release channel, we're gonna spawn off a cli of that version, with trailing args passed along.
+        use std::str::FromStr as _;
+
+        if let Ok(channel) = release_channel::ReleaseChannel::from_str(&channel[2..]) {
+            return mac_os::spawn_channel_cli(channel, std::env::args().skip(2).collect());
+        }
+    }
+    let args = Args::parse();
+
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    let args = flatpak::set_bin_if_no_escape(args);
+
+    let app = Detect::detect(args.zed.as_deref()).context("Bundle detection")?;
+
+    if args.version {
+        println!("{}", app.zed_version_string());
+        return Ok(());
+    }
+
+    let (server, server_name) =
+        IpcOneShotServer::<IpcHandshake>::new().context("Handshake before Zed spawn")?;
+    let url = format!("zed-cli://{server_name}");
+
+    let open_new_workspace = if args.new {
+        Some(true)
+    } else if args.add {
+        Some(false)
+    } else {
+        None
+    };
+
+    let env = Some(std::env::vars().collect::<HashMap<_, _>>());
+    let exit_status = Arc::new(Mutex::new(None));
+    let mut paths = vec![];
+    let mut urls = vec![];
+    let mut stdin_tmp_file: Option<fs::File> = None;
+    for path in args.paths_with_position.iter() {
+        if path.starts_with("zed://")
+            || path.starts_with("http://")
+            || path.starts_with("https://")
+            || path.starts_with("file://")
+            || path.starts_with("ssh://")
+        {
+            urls.push(path.to_string());
+        } else if path == "-" && args.paths_with_position.len() == 1 {
+            let file = NamedTempFile::new()?;
+            paths.push(file.path().to_string_lossy().to_string());
+            let (file, _) = file.keep()?;
+            stdin_tmp_file = Some(file);
+        } else {
+            paths.push(parse_path_with_position(path)?)
+        }
+    }
+
+    if let Some(_) = args.dev_server_token {
+        return Err(anyhow::anyhow!(
+            "Dev servers were removed in v0.157.x please upgrade to SSH remoting: https://zed.dev/docs/remote-development"
+        ))?;
+    }
+
+    let sender: JoinHandle<anyhow::Result<()>> = thread::spawn({
+        let exit_status = exit_status.clone();
+        move || {
+            let (_, handshake) = server.accept().context("Handshake after Zed spawn")?;
+            let (tx, rx) = (handshake.requests, handshake.responses);
+
+            tx.send(CliRequest::Open {
+                paths,
+                urls,
+                wait: args.wait,
+                open_new_workspace,
+                env,
+            })?;
+
+            while let Ok(response) = rx.recv() {
+                match response {
+                    CliResponse::Ping => {}
+                    CliResponse::Stdout { message } => println!("{message}"),
+                    CliResponse::Stderr { message } => eprintln!("{message}"),
+                    CliResponse::Exit { status } => {
+                        exit_status.lock().replace(status);
+                        return Ok(());
+                    }
+                }
+            }
+
+            Ok(())
+        }
+    });
+
+    let pipe_handle: JoinHandle<anyhow::Result<()>> = thread::spawn(move || {
+        if let Some(mut tmp_file) = stdin_tmp_file {
+            let mut stdin = std::io::stdin().lock();
+            if io::IsTerminal::is_terminal(&stdin) {
+                return Ok(());
+            }
+            let mut buffer = [0; 8 * 1024];
+            loop {
+                let bytes_read = io::Read::read(&mut stdin, &mut buffer)?;
+                if bytes_read == 0 {
+                    break;
+                }
+                io::Write::write(&mut tmp_file, &buffer[..bytes_read])?;
+            }
+            io::Write::flush(&mut tmp_file)?;
+        }
+        Ok(())
+    });
+
+    if args.foreground {
+        app.run_foreground(url)?;
+    } else {
+        app.launch(url)?;
+        sender.join().unwrap()?;
+        pipe_handle.join().unwrap()?;
+    }
+
+    if let Some(exit_status) = exit_status.lock().take() {
+        std::process::exit(exit_status);
+    }
+    Ok(())
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod linux {
+    use std::{
+        env,
+        ffi::OsString,
+        io,
+        os::unix::net::{SocketAddr, UnixDatagram},
+        path::{Path, PathBuf},
+        process::{self, ExitStatus},
+        thread,
+        time::Duration,
+    };
+
+    use anyhow::anyhow;
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+    use fork::Fork;
+    use once_cell::sync::Lazy;
+
+    use crate::{Detect, InstalledApp};
+
+    static RELEASE_CHANNEL: Lazy<String> =
+        Lazy::new(|| include_str!("../../zed/RELEASE_CHANNEL").trim().to_string());
+
+    struct App(PathBuf);
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let path = if let Some(path) = path {
+                path.to_path_buf().canonicalize()?
+            } else {
+                let cli = env::current_exe()?;
+                let dir = cli
+                    .parent()
+                    .ok_or_else(|| anyhow!("no parent path for cli"))?;
+
+                // libexec is the standard, lib/zed is for Arch (and other non-libexec distros),
+                // ./zed is for the target directory in development builds.
+                let possible_locations =
+                    ["../libexec/zed-editor", "../lib/zed/zed-editor", "./zed"];
+                possible_locations
+                    .iter()
+                    .find_map(|p| dir.join(p).canonicalize().ok().filter(|path| path != &cli))
+                    .ok_or_else(|| {
+                        anyhow!("could not find any of: {}", possible_locations.join(", "))
+                    })?
+            };
+
+            Ok(App(path))
+        }
+    }
+
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            format!(
+                "Zed {}{} – {}",
+                if *RELEASE_CHANNEL == "stable" {
+                    "".to_string()
+                } else {
+                    format!(" {} ", *RELEASE_CHANNEL)
+                },
+                option_env!("RELEASE_VERSION").unwrap_or_default(),
+                self.0.display(),
+            )
+        }
+
+        fn launch(&self, ipc_url: String) -> anyhow::Result<()> {
+            let sock_path = paths::support_dir().join(format!("zed-{}.sock", *RELEASE_CHANNEL));
+            let sock = UnixDatagram::unbound()?;
+            if sock.connect(&sock_path).is_err() {
+                self.boot_background(ipc_url)?;
+            } else {
+                sock.send(ipc_url.as_bytes())?;
+            }
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            std::process::Command::new(self.0.clone())
+                .arg(ipc_url)
+                .status()
+        }
+    }
+
+    impl App {
+        fn boot_background(&self, ipc_url: String) -> anyhow::Result<()> {
+            let path = &self.0;
+
+            match fork::fork() {
+                Ok(Fork::Parent(_)) => Ok(()),
+                Ok(Fork::Child) => {
+                    std::env::set_var(FORCE_CLI_MODE_ENV_VAR_NAME, "");
+                    if let Err(_) = fork::setsid() {
+                        eprintln!("failed to setsid: {}", std::io::Error::last_os_error());
+                        process::exit(1);
+                    }
+                    if let Err(_) = fork::close_fd() {
+                        eprintln!("failed to close_fd: {}", std::io::Error::last_os_error());
+                    }
+                    let error =
+                        exec::execvp(path.clone(), &[path.as_os_str(), &OsString::from(ipc_url)]);
+                    // if exec succeeded, we never get here.
+                    eprintln!("failed to exec {:?}: {}", path, error);
+                    process::exit(1)
+                }
+                Err(_) => Err(anyhow!(io::Error::last_os_error())),
+            }
+        }
+
+        fn wait_for_socket(
+            &self,
+            sock_addr: &SocketAddr,
+            sock: &mut UnixDatagram,
+        ) -> Result<(), std::io::Error> {
+            for _ in 0..100 {
+                thread::sleep(Duration::from_millis(10));
+                if sock.connect_addr(&sock_addr).is_ok() {
+                    return Ok(());
+                }
+            }
+            sock.connect_addr(&sock_addr)
+        }
+    }
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod flatpak {
+    use std::ffi::OsString;
+    use std::path::PathBuf;
+    use std::process::Command;
+    use std::{env, process};
+
+    const EXTRA_LIB_ENV_NAME: &'static str = "ZED_FLATPAK_LIB_PATH";
+    const NO_ESCAPE_ENV_NAME: &'static str = "ZED_FLATPAK_NO_ESCAPE";
+
+    /// Adds bundled libraries to LD_LIBRARY_PATH if running under flatpak
+    pub fn ld_extra_libs() {
+        let mut paths = if let Ok(paths) = env::var("LD_LIBRARY_PATH") {
+            env::split_paths(&paths).collect()
+        } else {
+            Vec::new()
+        };
+
+        if let Ok(extra_path) = env::var(EXTRA_LIB_ENV_NAME) {
+            paths.push(extra_path.into());
+        }
+
+        env::set_var("LD_LIBRARY_PATH", env::join_paths(paths).unwrap());
+    }
+
+    /// Restarts outside of the sandbox if currently running within it
+    pub fn try_restart_to_host() {
+        if let Some(flatpak_dir) = get_flatpak_dir() {
+            let mut args = vec!["/usr/bin/flatpak-spawn".into(), "--host".into()];
+            args.append(&mut get_xdg_env_args());
+            args.push("--env=ZED_UPDATE_EXPLANATION=Please use flatpak to update zed".into());
+            args.push(
+                format!(
+                    "--env={EXTRA_LIB_ENV_NAME}={}",
+                    flatpak_dir.join("lib").to_str().unwrap()
+                )
+                .into(),
+            );
+            args.push(flatpak_dir.join("bin").join("zed").into());
+
+            let mut is_app_location_set = false;
+            for arg in &env::args_os().collect::<Vec<_>>()[1..] {
+                args.push(arg.clone());
+                is_app_location_set |= arg == "--zed";
+            }
+
+            if !is_app_location_set {
+                args.push("--zed".into());
+                args.push(flatpak_dir.join("libexec").join("zed-editor").into());
+            }
+
+            let error = exec::execvp("/usr/bin/flatpak-spawn", args);
+            eprintln!("failed restart cli on host: {:?}", error);
+            process::exit(1);
+        }
+    }
+
+    pub fn set_bin_if_no_escape(mut args: super::Args) -> super::Args {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok()
+            && env::var("FLATPAK_ID").map_or(false, |id| id.starts_with("dev.zed.Zed"))
+        {
+            if args.zed.is_none() {
+                args.zed = Some("/app/libexec/zed-editor".into());
+                env::set_var("ZED_UPDATE_EXPLANATION", "Please use flatpak to update zed");
+            }
+        }
+        args
+    }
+
+    fn get_flatpak_dir() -> Option<PathBuf> {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok() {
+            return None;
+        }
+
+        if let Ok(flatpak_id) = env::var("FLATPAK_ID") {
+            if !flatpak_id.starts_with("dev.zed.Zed") {
+                return None;
+            }
+
+            let install_dir = Command::new("/usr/bin/flatpak-spawn")
+                .arg("--host")
+                .arg("flatpak")
+                .arg("info")
+                .arg("--show-location")
+                .arg(flatpak_id)
+                .output()
+                .unwrap();
+            let install_dir = PathBuf::from(String::from_utf8(install_dir.stdout).unwrap().trim());
+            Some(install_dir.join("files"))
+        } else {
+            None
+        }
+    }
+
+    fn get_xdg_env_args() -> Vec<OsString> {
+        let xdg_keys = [
+            "XDG_DATA_HOME",
+            "XDG_CONFIG_HOME",
+            "XDG_CACHE_HOME",
+            "XDG_STATE_HOME",
+        ];
+        env::vars()
+            .filter(|(key, _)| xdg_keys.contains(&key.as_str()))
+            .map(|(key, val)| format!("--env=FLATPAK_{}={}", key, val).into())
+            .collect()
+    }
+}
+
+// todo("windows")
+#[cfg(target_os = "windows")]
+mod windows {
+    use crate::{Detect, InstalledApp};
+    use std::io;
+    use std::path::Path;
+    use std::process::ExitStatus;
+
+    struct App;
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            unimplemented!()
+        }
+        fn launch(&self, _ipc_url: String) -> anyhow::Result<()> {
+            unimplemented!()
+        }
+        fn run_foreground(&self, _ipc_url: String) -> io::Result<ExitStatus> {
+            unimplemented!()
+        }
+    }
+
+    impl Detect {
+        pub fn detect(_path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            Ok(App)
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+mod mac_os {
+    use anyhow::{anyhow, Context, Result};
+    use core_foundation::{
+        array::{CFArray, CFIndex},
+        string::kCFStringEncodingUTF8,
+        url::{CFURLCreateWithBytes, CFURL},
+    };
+    use core_services::{kLSLaunchDefaults, LSLaunchURLSpec, LSOpenFromURLSpec, TCFType};
+    use serde::Deserialize;
+    use std::{
+        ffi::OsStr,
+        fs, io,
+        path::{Path, PathBuf},
+        process::{Command, ExitStatus},
+        ptr,
+    };
+
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+
+    use crate::{Detect, InstalledApp};
+
+    #[derive(Debug, Deserialize)]
+    struct InfoPlist {
+        #[serde(rename = "CFBundleShortVersionString")]
+        bundle_short_version_string: String,
+    }
+
+    enum Bundle {
+        App {
+            app_bundle: PathBuf,
+            plist: InfoPlist,
+        },
+        LocalPath {
+            executable: PathBuf,
+            plist: InfoPlist,
+        },
+    }
+
+    fn locate_bundle() -> Result<PathBuf> {
+        let cli_path = std::env::current_exe()?.canonicalize()?;
+        let mut app_path = cli_path.clone();
+        while app_path.extension() != Some(OsStr::new("app")) {
+            if !app_path.pop() {
+                return Err(anyhow!("cannot find app bundle containing {:?}", cli_path));
+            }
+        }
+        Ok(app_path)
+    }
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let bundle_path = if let Some(bundle_path) = path {
+                bundle_path
+                    .canonicalize()
+                    .with_context(|| format!("Args bundle path {bundle_path:?} canonicalization"))?
+            } else {
+                locate_bundle().context("bundle autodiscovery")?
+            };
+
+            match bundle_path.extension().and_then(|ext| ext.to_str()) {
+                Some("app") => {
+                    let plist_path = bundle_path.join("Contents/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading *.app bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::App {
+                        app_bundle: bundle_path,
+                        plist,
+                    })
+                }
+                _ => {
+                    println!("Bundle path {bundle_path:?} has no *.app extension, attempting to locate a dev build");
+                    let plist_path = bundle_path
+                        .parent()
+                        .with_context(|| format!("Bundle path {bundle_path:?} has no parent"))?
+                        .join("WebRTC.framework/Resources/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading dev bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::LocalPath {
+                        executable: bundle_path,
+                        plist,
+                    })
+                }
+            }
+        }
+    }
+
+    impl InstalledApp for Bundle {
+        fn zed_version_string(&self) -> String {
+            let is_dev = matches!(self, Self::LocalPath { .. });
+            format!(
+                "Zed {}{} – {}",
+                self.plist().bundle_short_version_string,
+                if is_dev { " (dev)" } else { "" },
+                self.path().display(),
+            )
+        }
+
+        fn launch(&self, url: String) -> anyhow::Result<()> {
+            match self {
+                Self::App { app_bundle, .. } => {
+                    let app_path = app_bundle;
+
+                    let status = unsafe {
+                        let app_url = CFURL::from_path(app_path, true)
+                            .with_context(|| format!("invalid app path {app_path:?}"))?;
+                        let url_to_open = CFURL::wrap_under_create_rule(CFURLCreateWithBytes(
+                            ptr::null(),
+                            url.as_ptr(),
+                            url.len() as CFIndex,
+                            kCFStringEncodingUTF8,
+                            ptr::null(),
+                        ));
+                        // equivalent to: open zed-cli:... -a /Applications/Zed\ Preview.app
+                        let urls_to_open =
+                            CFArray::from_copyable(&[url_to_open.as_concrete_TypeRef()]);
+                        LSOpenFromURLSpec(
+                            &LSLaunchURLSpec {
+                                appURL: app_url.as_concrete_TypeRef(),
+                                itemURLs: urls_to_open.as_concrete_TypeRef(),
+                                passThruParams: ptr::null(),
+                                launchFlags: kLSLaunchDefaults,
+                                asyncRefCon: ptr::null_mut(),
+                            },
+                            ptr::null_mut(),
+                        )
+                    };
+
+                    anyhow::ensure!(
+                        status == 0,
+                        "cannot start app bundle {}",
+                        self.zed_version_string()
+                    );
+                }
+
+                Self::LocalPath { executable, .. } => {
+                    let executable_parent = executable
+                        .parent()
+                        .with_context(|| format!("Executable {executable:?} path has no parent"))?;
+                    let subprocess_stdout_file = fs::File::create(
+                        executable_parent.join("zed_dev.log"),
+                    )
+                    .with_context(|| format!("Log file creation in {executable_parent:?}"))?;
+                    let subprocess_stdin_file =
+                        subprocess_stdout_file.try_clone().with_context(|| {
+                            format!("Cloning descriptor for file {subprocess_stdout_file:?}")
+                        })?;
+                    let mut command = std::process::Command::new(executable);
+                    let command = command
+                        .env(FORCE_CLI_MODE_ENV_VAR_NAME, "")
+                        .stderr(subprocess_stdout_file)
+                        .stdout(subprocess_stdin_file)
+                        .arg(url);
+
+                    command
+                        .spawn()
+                        .with_context(|| format!("Spawning {command:?}"))?;
+                }
+            }
+
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            let path = match self {
+                Bundle::App { app_bundle, .. } => app_bundle.join("Contents/MacOS/zed"),
+                Bundle::LocalPath { executable, .. } => executable.clone(),
+            };
+
+            std::process::Command::new(path).arg(ipc_url).status()
+        }
+    }
+
+    impl Bundle {
+        fn plist(&self) -> &InfoPlist {
+            match self {
+                Self::App { plist, .. } => plist,
+                Self::LocalPath { plist, .. } => plist,
+            }
+        }
+
+        fn path(&self) -> &Path {
+            match self {
+                Self::App { app_bundle, .. } => app_bundle,
+                Self::LocalPath { executable, .. } => executable,
+            }
+        }
+    }
+
+    pub(super) fn spawn_channel_cli(
+        channel: release_channel::ReleaseChannel,
+        leftover_args: Vec<String>,
+    ) -> Result<()> {
+        use anyhow::bail;
+
+        let app_id_prompt = format!("id of app \"{}\"", channel.display_name());
+        let app_id_output = Command::new("osascript")
+            .arg("-e")
+            .arg(&app_id_prompt)
+            .output()?;
+        if !app_id_output.status.success() {
+            bail!("Could not determine app id for {}", channel.display_name());
+        }
+        let app_name = String::from_utf8(app_id_output.stdout)?.trim().to_owned();
+        let app_path_prompt = format!("kMDItemCFBundleIdentifier == '{app_name}'");
+        let app_path_output = Command::new("mdfind").arg(app_path_prompt).output()?;
+        if !app_path_output.status.success() {
+            bail!(
+                "Could not determine app path for {}",
+                channel.display_name()
+            );
+        }
+        let app_path = String::from_utf8(app_path_output.stdout)?.trim().to_owned();
+        let cli_path = format!("{app_path}/Contents/MacOS/cli");
+        Command::new(cli_path).args(leftover_args).spawn()?;
+        Ok(())
+    }
+}

crates/zeta/fixtures/new-cli-arg/edit2.rs

@@ -0,0 +1,712 @@
+#![cfg_attr(
+    any(target_os = "linux", target_os = "freebsd", target_os = "windows"),
+    allow(dead_code)
+)]
+
+use anyhow::{Context, Result};
+use clap::Parser;
+use cli::{ipc::IpcOneShotServer, CliRequest, CliResponse, IpcHandshake};
+use collections::HashMap;
+use parking_lot::Mutex;
+use std::{
+    env, fs, io,
+    path::{Path, PathBuf},
+    process::ExitStatus,
+    sync::Arc,
+    thread::{self, JoinHandle},
+};
+use tempfile::NamedTempFile;
+use util::paths::PathWithPosition;
+
+struct Detect;
+
+trait InstalledApp {
+    fn zed_version_string(&self) -> String;
+    fn launch(&self, ipc_url: String) -> anyhow::Result<()>;
+    fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus>;
+}
+
+#[derive(Parser, Debug)]
+#[command(
+    name = "zed",
+    disable_version_flag = true,
+    after_help = "To read from stdin, append '-' (e.g. 'ps axf | zed -')"
+)]
+struct Args {
+    /// Wait for all of the given paths to be opened/closed before exiting.
+    #[arg(short, long)]
+    wait: bool,
+    /// Add files to the currently open workspace
+    #[arg(short, long, overrides_with = "new")]
+    add: bool,
+    /// Create a new workspace
+    #[arg(short, long, overrides_with = "add")]
+    new: bool,
+    /// A sequence of space-separated paths that you want to open.
+    ///
+    /// Use `path:line:row` syntax to open a file at a specific location.
+    /// Non-existing paths and directories will ignore `:line:row` suffix.
+    paths_with_position: Vec<String>,
+    /// Print Zed's version and the app path.
+    #[arg(short, long)]
+    version: bool,
+    /// Run zed in the foreground (useful for debugging)
+    #[arg(long)]
+    foreground: bool,
+    /// Custom path to Zed.app or the zed binary
+    #[arg(long)]
+    zed: Option<PathBuf>,
+    /// Run zed in dev-server mode
+    #[arg(long)]
+    dev_server_token: Option<String>,
+    /// Only update the Zed instance
+    #[arg(long)]
+    update: bool,
+}
+
+fn parse_path_with_position(argument_str: &str) -> anyhow::Result<String> {
+    let canonicalized = match Path::new(argument_str).canonicalize() {
+        Ok(existing_path) => PathWithPosition::from_path(existing_path),
+        Err(_) => {
+            let path = PathWithPosition::parse_str(argument_str);
+            let curdir = env::current_dir().context("reteiving current directory")?;
+            path.map_path(|path| match fs::canonicalize(&path) {
+                Ok(path) => Ok(path),
+                Err(e) => {
+                    if let Some(mut parent) = path.parent() {
+                        if parent == Path::new("") {
+                            parent = &curdir
+                        }
+                        match fs::canonicalize(parent) {
+                            Ok(parent) => Ok(parent.join(path.file_name().unwrap())),
+                            Err(_) => Err(e),
+                        }
+                    } else {
+                        Err(e)
+                    }
+                }
+            })
+        }
+        .with_context(|| format!("parsing as path with position {argument_str}"))?,
+    };
+    Ok(canonicalized.to_string(|path| path.to_string_lossy().to_string()))
+}
+
+fn main() -> Result<()> {
+    // Exit flatpak sandbox if needed
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    {
+        flatpak::try_restart_to_host();
+        flatpak::ld_extra_libs();
+    }
+
+    // Intercept version designators
+    #[cfg(target_os = "macos")]
+    if let Some(channel) = std::env::args().nth(1).filter(|arg| arg.starts_with("--")) {
+        // When the first argument is a name of a release channel, we're gonna spawn off a cli of that version, with trailing args passed along.
+        use std::str::FromStr as _;
+
+        if let Ok(channel) = release_channel::ReleaseChannel::from_str(&channel[2..]) {
+            return mac_os::spawn_channel_cli(channel, std::env::args().skip(2).collect());
+        }
+    }
+    let args = Args::parse();
+
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    let args = flatpak::set_bin_if_no_escape(args);
+
+    let app = Detect::detect(args.zed.as_deref()).context("Bundle detection")?;
+
+    if args.version {
+        println!("{}", app.zed_version_string());
+        return Ok(());
+    }
+
+    if<|user_cursor_is_here|>
+
+    let (server, server_name) =
+        IpcOneShotServer::<IpcHandshake>::new().context("Handshake before Zed spawn")?;
+    let url = format!("zed-cli://{server_name}");
+
+    let open_new_workspace = if args.new {
+        Some(true)
+    } else if args.add {
+        Some(false)
+    } else {
+        None
+    };
+
+    let env = Some(std::env::vars().collect::<HashMap<_, _>>());
+    let exit_status = Arc::new(Mutex::new(None));
+    let mut paths = vec![];
+    let mut urls = vec![];
+    let mut stdin_tmp_file: Option<fs::File> = None;
+    for path in args.paths_with_position.iter() {
+        if path.starts_with("zed://")
+            || path.starts_with("http://")
+            || path.starts_with("https://")
+            || path.starts_with("file://")
+            || path.starts_with("ssh://")
+        {
+            urls.push(path.to_string());
+        } else if path == "-" && args.paths_with_position.len() == 1 {
+            let file = NamedTempFile::new()?;
+            paths.push(file.path().to_string_lossy().to_string());
+            let (file, _) = file.keep()?;
+            stdin_tmp_file = Some(file);
+        } else {
+            paths.push(parse_path_with_position(path)?)
+        }
+    }
+
+    if let Some(_) = args.dev_server_token {
+        return Err(anyhow::anyhow!(
+            "Dev servers were removed in v0.157.x please upgrade to SSH remoting: https://zed.dev/docs/remote-development"
+        ))?;
+    }
+
+    let sender: JoinHandle<anyhow::Result<()>> = thread::spawn({
+        let exit_status = exit_status.clone();
+        move || {
+            let (_, handshake) = server.accept().context("Handshake after Zed spawn")?;
+            let (tx, rx) = (handshake.requests, handshake.responses);
+
+            tx.send(CliRequest::Open {
+                paths,
+                urls,
+                wait: args.wait,
+                open_new_workspace,
+                env,
+            })?;
+
+            while let Ok(response) = rx.recv() {
+                match response {
+                    CliResponse::Ping => {}
+                    CliResponse::Stdout { message } => println!("{message}"),
+                    CliResponse::Stderr { message } => eprintln!("{message}"),
+                    CliResponse::Exit { status } => {
+                        exit_status.lock().replace(status);
+                        return Ok(());
+                    }
+                }
+            }
+
+            Ok(())
+        }
+    });
+
+    let pipe_handle: JoinHandle<anyhow::Result<()>> = thread::spawn(move || {
+        if let Some(mut tmp_file) = stdin_tmp_file {
+            let mut stdin = std::io::stdin().lock();
+            if io::IsTerminal::is_terminal(&stdin) {
+                return Ok(());
+            }
+            let mut buffer = [0; 8 * 1024];
+            loop {
+                let bytes_read = io::Read::read(&mut stdin, &mut buffer)?;
+                if bytes_read == 0 {
+                    break;
+                }
+                io::Write::write(&mut tmp_file, &buffer[..bytes_read])?;
+            }
+            io::Write::flush(&mut tmp_file)?;
+        }
+        Ok(())
+    });
+
+    if args.foreground {
+        app.run_foreground(url)?;
+    } else {
+        app.launch(url)?;
+        sender.join().unwrap()?;
+        pipe_handle.join().unwrap()?;
+    }
+
+    if let Some(exit_status) = exit_status.lock().take() {
+        std::process::exit(exit_status);
+    }
+    Ok(())
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod linux {
+    use std::{
+        env,
+        ffi::OsString,
+        io,
+        os::unix::net::{SocketAddr, UnixDatagram},
+        path::{Path, PathBuf},
+        process::{self, ExitStatus},
+        thread,
+        time::Duration,
+    };
+
+    use anyhow::anyhow;
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+    use fork::Fork;
+    use once_cell::sync::Lazy;
+
+    use crate::{Detect, InstalledApp};
+
+    static RELEASE_CHANNEL: Lazy<String> =
+        Lazy::new(|| include_str!("../../zed/RELEASE_CHANNEL").trim().to_string());
+
+    struct App(PathBuf);
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let path = if let Some(path) = path {
+                path.to_path_buf().canonicalize()?
+            } else {
+                let cli = env::current_exe()?;
+                let dir = cli
+                    .parent()
+                    .ok_or_else(|| anyhow!("no parent path for cli"))?;
+
+                // libexec is the standard, lib/zed is for Arch (and other non-libexec distros),
+                // ./zed is for the target directory in development builds.
+                let possible_locations =
+                    ["../libexec/zed-editor", "../lib/zed/zed-editor", "./zed"];
+                possible_locations
+                    .iter()
+                    .find_map(|p| dir.join(p).canonicalize().ok().filter(|path| path != &cli))
+                    .ok_or_else(|| {
+                        anyhow!("could not find any of: {}", possible_locations.join(", "))
+                    })?
+            };
+
+            Ok(App(path))
+        }
+    }
+
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            format!(
+                "Zed {}{} – {}",
+                if *RELEASE_CHANNEL == "stable" {
+                    "".to_string()
+                } else {
+                    format!(" {} ", *RELEASE_CHANNEL)
+                },
+                option_env!("RELEASE_VERSION").unwrap_or_default(),
+                self.0.display(),
+            )
+        }
+
+        fn launch(&self, ipc_url: String) -> anyhow::Result<()> {
+            let sock_path = paths::support_dir().join(format!("zed-{}.sock", *RELEASE_CHANNEL));
+            let sock = UnixDatagram::unbound()?;
+            if sock.connect(&sock_path).is_err() {
+                self.boot_background(ipc_url)?;
+            } else {
+                sock.send(ipc_url.as_bytes())?;
+            }
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            std::process::Command::new(self.0.clone())
+                .arg(ipc_url)
+                .status()
+        }
+    }
+
+    impl App {
+        fn boot_background(&self, ipc_url: String) -> anyhow::Result<()> {
+            let path = &self.0;
+
+            match fork::fork() {
+                Ok(Fork::Parent(_)) => Ok(()),
+                Ok(Fork::Child) => {
+                    std::env::set_var(FORCE_CLI_MODE_ENV_VAR_NAME, "");
+                    if let Err(_) = fork::setsid() {
+                        eprintln!("failed to setsid: {}", std::io::Error::last_os_error());
+                        process::exit(1);
+                    }
+                    if let Err(_) = fork::close_fd() {
+                        eprintln!("failed to close_fd: {}", std::io::Error::last_os_error());
+                    }
+                    let error =
+                        exec::execvp(path.clone(), &[path.as_os_str(), &OsString::from(ipc_url)]);
+                    // if exec succeeded, we never get here.
+                    eprintln!("failed to exec {:?}: {}", path, error);
+                    process::exit(1)
+                }
+                Err(_) => Err(anyhow!(io::Error::last_os_error())),
+            }
+        }
+
+        fn wait_for_socket(
+            &self,
+            sock_addr: &SocketAddr,
+            sock: &mut UnixDatagram,
+        ) -> Result<(), std::io::Error> {
+            for _ in 0..100 {
+                thread::sleep(Duration::from_millis(10));
+                if sock.connect_addr(&sock_addr).is_ok() {
+                    return Ok(());
+                }
+            }
+            sock.connect_addr(&sock_addr)
+        }
+    }
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod flatpak {
+    use std::ffi::OsString;
+    use std::path::PathBuf;
+    use std::process::Command;
+    use std::{env, process};
+
+    const EXTRA_LIB_ENV_NAME: &'static str = "ZED_FLATPAK_LIB_PATH";
+    const NO_ESCAPE_ENV_NAME: &'static str = "ZED_FLATPAK_NO_ESCAPE";
+
+    /// Adds bundled libraries to LD_LIBRARY_PATH if running under flatpak
+    pub fn ld_extra_libs() {
+        let mut paths = if let Ok(paths) = env::var("LD_LIBRARY_PATH") {
+            env::split_paths(&paths).collect()
+        } else {
+            Vec::new()
+        };
+
+        if let Ok(extra_path) = env::var(EXTRA_LIB_ENV_NAME) {
+            paths.push(extra_path.into());
+        }
+
+        env::set_var("LD_LIBRARY_PATH", env::join_paths(paths).unwrap());
+    }
+
+    /// Restarts outside of the sandbox if currently running within it
+    pub fn try_restart_to_host() {
+        if let Some(flatpak_dir) = get_flatpak_dir() {
+            let mut args = vec!["/usr/bin/flatpak-spawn".into(), "--host".into()];
+            args.append(&mut get_xdg_env_args());
+            args.push("--env=ZED_UPDATE_EXPLANATION=Please use flatpak to update zed".into());
+            args.push(
+                format!(
+                    "--env={EXTRA_LIB_ENV_NAME}={}",
+                    flatpak_dir.join("lib").to_str().unwrap()
+                )
+                .into(),
+            );
+            args.push(flatpak_dir.join("bin").join("zed").into());
+
+            let mut is_app_location_set = false;
+            for arg in &env::args_os().collect::<Vec<_>>()[1..] {
+                args.push(arg.clone());
+                is_app_location_set |= arg == "--zed";
+            }
+
+            if !is_app_location_set {
+                args.push("--zed".into());
+                args.push(flatpak_dir.join("libexec").join("zed-editor").into());
+            }
+
+            let error = exec::execvp("/usr/bin/flatpak-spawn", args);
+            eprintln!("failed restart cli on host: {:?}", error);
+            process::exit(1);
+        }
+    }
+
+    pub fn set_bin_if_no_escape(mut args: super::Args) -> super::Args {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok()
+            && env::var("FLATPAK_ID").map_or(false, |id| id.starts_with("dev.zed.Zed"))
+        {
+            if args.zed.is_none() {
+                args.zed = Some("/app/libexec/zed-editor".into());
+                env::set_var("ZED_UPDATE_EXPLANATION", "Please use flatpak to update zed");
+            }
+        }
+        args
+    }
+
+    fn get_flatpak_dir() -> Option<PathBuf> {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok() {
+            return None;
+        }
+
+        if let Ok(flatpak_id) = env::var("FLATPAK_ID") {
+            if !flatpak_id.starts_with("dev.zed.Zed") {
+                return None;
+            }
+
+            let install_dir = Command::new("/usr/bin/flatpak-spawn")
+                .arg("--host")
+                .arg("flatpak")
+                .arg("info")
+                .arg("--show-location")
+                .arg(flatpak_id)
+                .output()
+                .unwrap();
+            let install_dir = PathBuf::from(String::from_utf8(install_dir.stdout).unwrap().trim());
+            Some(install_dir.join("files"))
+        } else {
+            None
+        }
+    }
+
+    fn get_xdg_env_args() -> Vec<OsString> {
+        let xdg_keys = [
+            "XDG_DATA_HOME",
+            "XDG_CONFIG_HOME",
+            "XDG_CACHE_HOME",
+            "XDG_STATE_HOME",
+        ];
+        env::vars()
+            .filter(|(key, _)| xdg_keys.contains(&key.as_str()))
+            .map(|(key, val)| format!("--env=FLATPAK_{}={}", key, val).into())
+            .collect()
+    }
+}
+
+// todo("windows")
+#[cfg(target_os = "windows")]
+mod windows {
+    use crate::{Detect, InstalledApp};
+    use std::io;
+    use std::path::Path;
+    use std::process::ExitStatus;
+
+    struct App;
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            unimplemented!()
+        }
+        fn launch(&self, _ipc_url: String) -> anyhow::Result<()> {
+            unimplemented!()
+        }
+        fn run_foreground(&self, _ipc_url: String) -> io::Result<ExitStatus> {
+            unimplemented!()
+        }
+    }
+
+    impl Detect {
+        pub fn detect(_path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            Ok(App)
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+mod mac_os {
+    use anyhow::{anyhow, Context, Result};
+    use core_foundation::{
+        array::{CFArray, CFIndex},
+        string::kCFStringEncodingUTF8,
+        url::{CFURLCreateWithBytes, CFURL},
+    };
+    use core_services::{kLSLaunchDefaults, LSLaunchURLSpec, LSOpenFromURLSpec, TCFType};
+    use serde::Deserialize;
+    use std::{
+        ffi::OsStr,
+        fs, io,
+        path::{Path, PathBuf},
+        process::{Command, ExitStatus},
+        ptr,
+    };
+
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+
+    use crate::{Detect, InstalledApp};
+
+    #[derive(Debug, Deserialize)]
+    struct InfoPlist {
+        #[serde(rename = "CFBundleShortVersionString")]
+        bundle_short_version_string: String,
+    }
+
+    enum Bundle {
+        App {
+            app_bundle: PathBuf,
+            plist: InfoPlist,
+        },
+        LocalPath {
+            executable: PathBuf,
+            plist: InfoPlist,
+        },
+    }
+
+    fn locate_bundle() -> Result<PathBuf> {
+        let cli_path = std::env::current_exe()?.canonicalize()?;
+        let mut app_path = cli_path.clone();
+        while app_path.extension() != Some(OsStr::new("app")) {
+            if !app_path.pop() {
+                return Err(anyhow!("cannot find app bundle containing {:?}", cli_path));
+            }
+        }
+        Ok(app_path)
+    }
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let bundle_path = if let Some(bundle_path) = path {
+                bundle_path
+                    .canonicalize()
+                    .with_context(|| format!("Args bundle path {bundle_path:?} canonicalization"))?
+            } else {
+                locate_bundle().context("bundle autodiscovery")?
+            };
+
+            match bundle_path.extension().and_then(|ext| ext.to_str()) {
+                Some("app") => {
+                    let plist_path = bundle_path.join("Contents/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading *.app bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::App {
+                        app_bundle: bundle_path,
+                        plist,
+                    })
+                }
+                _ => {
+                    println!("Bundle path {bundle_path:?} has no *.app extension, attempting to locate a dev build");
+                    let plist_path = bundle_path
+                        .parent()
+                        .with_context(|| format!("Bundle path {bundle_path:?} has no parent"))?
+                        .join("WebRTC.framework/Resources/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading dev bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::LocalPath {
+                        executable: bundle_path,
+                        plist,
+                    })
+                }
+            }
+        }
+    }
+
+    impl InstalledApp for Bundle {
+        fn zed_version_string(&self) -> String {
+            let is_dev = matches!(self, Self::LocalPath { .. });
+            format!(
+                "Zed {}{} – {}",
+                self.plist().bundle_short_version_string,
+                if is_dev { " (dev)" } else { "" },
+                self.path().display(),
+            )
+        }
+
+        fn launch(&self, url: String) -> anyhow::Result<()> {
+            match self {
+                Self::App { app_bundle, .. } => {
+                    let app_path = app_bundle;
+
+                    let status = unsafe {
+                        let app_url = CFURL::from_path(app_path, true)
+                            .with_context(|| format!("invalid app path {app_path:?}"))?;
+                        let url_to_open = CFURL::wrap_under_create_rule(CFURLCreateWithBytes(
+                            ptr::null(),
+                            url.as_ptr(),
+                            url.len() as CFIndex,
+                            kCFStringEncodingUTF8,
+                            ptr::null(),
+                        ));
+                        // equivalent to: open zed-cli:... -a /Applications/Zed\ Preview.app
+                        let urls_to_open =
+                            CFArray::from_copyable(&[url_to_open.as_concrete_TypeRef()]);
+                        LSOpenFromURLSpec(
+                            &LSLaunchURLSpec {
+                                appURL: app_url.as_concrete_TypeRef(),
+                                itemURLs: urls_to_open.as_concrete_TypeRef(),
+                                passThruParams: ptr::null(),
+                                launchFlags: kLSLaunchDefaults,
+                                asyncRefCon: ptr::null_mut(),
+                            },
+                            ptr::null_mut(),
+                        )
+                    };
+
+                    anyhow::ensure!(
+                        status == 0,
+                        "cannot start app bundle {}",
+                        self.zed_version_string()
+                    );
+                }
+
+                Self::LocalPath { executable, .. } => {
+                    let executable_parent = executable
+                        .parent()
+                        .with_context(|| format!("Executable {executable:?} path has no parent"))?;
+                    let subprocess_stdout_file = fs::File::create(
+                        executable_parent.join("zed_dev.log"),
+                    )
+                    .with_context(|| format!("Log file creation in {executable_parent:?}"))?;
+                    let subprocess_stdin_file =
+                        subprocess_stdout_file.try_clone().with_context(|| {
+                            format!("Cloning descriptor for file {subprocess_stdout_file:?}")
+                        })?;
+                    let mut command = std::process::Command::new(executable);
+                    let command = command
+                        .env(FORCE_CLI_MODE_ENV_VAR_NAME, "")
+                        .stderr(subprocess_stdout_file)
+                        .stdout(subprocess_stdin_file)
+                        .arg(url);
+
+                    command
+                        .spawn()
+                        .with_context(|| format!("Spawning {command:?}"))?;
+                }
+            }
+
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            let path = match self {
+                Bundle::App { app_bundle, .. } => app_bundle.join("Contents/MacOS/zed"),
+                Bundle::LocalPath { executable, .. } => executable.clone(),
+            };
+
+            std::process::Command::new(path).arg(ipc_url).status()
+        }
+    }
+
+    impl Bundle {
+        fn plist(&self) -> &InfoPlist {
+            match self {
+                Self::App { plist, .. } => plist,
+                Self::LocalPath { plist, .. } => plist,
+            }
+        }
+
+        fn path(&self) -> &Path {
+            match self {
+                Self::App { app_bundle, .. } => app_bundle,
+                Self::LocalPath { executable, .. } => executable,
+            }
+        }
+    }
+
+    pub(super) fn spawn_channel_cli(
+        channel: release_channel::ReleaseChannel,
+        leftover_args: Vec<String>,
+    ) -> Result<()> {
+        use anyhow::bail;
+
+        let app_id_prompt = format!("id of app \"{}\"", channel.display_name());
+        let app_id_output = Command::new("osascript")
+            .arg("-e")
+            .arg(&app_id_prompt)
+            .output()?;
+        if !app_id_output.status.success() {
+            bail!("Could not determine app id for {}", channel.display_name());
+        }
+        let app_name = String::from_utf8(app_id_output.stdout)?.trim().to_owned();
+        let app_path_prompt = format!("kMDItemCFBundleIdentifier == '{app_name}'");
+        let app_path_output = Command::new("mdfind").arg(app_path_prompt).output()?;
+        if !app_path_output.status.success() {
+            bail!(
+                "Could not determine app path for {}",
+                channel.display_name()
+            );
+        }
+        let app_path = String::from_utf8(app_path_output.stdout)?.trim().to_owned();
+        let cli_path = format!("{app_path}/Contents/MacOS/cli");
+        Command::new(cli_path).args(leftover_args).spawn()?;
+        Ok(())
+    }
+}

crates/zeta/fixtures/new-cli-arg/initial.rs

@@ -0,0 +1,707 @@
+#![cfg_attr(
+    any(target_os = "linux", target_os = "freebsd", target_os = "windows"),
+    allow(dead_code)
+)]
+
+use anyhow::{Context, Result};
+use clap::Parser;
+use cli::{ipc::IpcOneShotServer, CliRequest, CliResponse, IpcHandshake};
+use collections::HashMap;
+use parking_lot::Mutex;
+use std::{
+    env, fs, io,
+    path::{Path, PathBuf},
+    process::ExitStatus,
+    sync::Arc,
+    thread::{self, JoinHandle},
+};
+use tempfile::NamedTempFile;
+use util::paths::PathWithPosition;
+
+struct Detect;
+
+trait InstalledApp {
+    fn zed_version_string(&self) -> String;
+    fn launch(&self, ipc_url: String) -> anyhow::Result<()>;
+    fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus>;
+}
+
+#[derive(Parser, Debug)]
+#[command(
+    name = "zed",
+    disable_version_flag = true,
+    after_help = "To read from stdin, append '-' (e.g. 'ps axf | zed -')"
+)]
+struct Args {
+    /// Wait for all of the given paths to be opened/closed before exiting.
+    #[arg(short, long)]
+    wait: bool,
+    /// Add files to the currently open workspace
+    #[arg(short, long, overrides_with = "new")]
+    add: bool,
+    /// Create a new workspace
+    #[arg(short, long, overrides_with = "add")]
+    new: bool,
+    /// A sequence of space-separated paths that you want to open.
+    ///
+    /// Use `path:line:row` syntax to open a file at a specific location.
+    /// Non-existing paths and directories will ignore `:line:row` suffix.
+    paths_with_position: Vec<String>,
+    /// Print Zed's version and the app path.
+    #[arg(short, long)]
+    version: bool,
+    /// Run zed in the foreground (useful for debugging)
+    #[arg(long)]
+    foreground: bool,
+    /// Custom path to Zed.app or the zed binary
+    #[arg(long)]
+    zed: Option<PathBuf>,
+    /// Run zed in dev-server mode
+    #[arg(long)]
+    dev_server_token: Option<String>,
+}
+
+fn parse_path_with_position(argument_str: &str) -> anyhow::Result<String> {
+    let canonicalized = match Path::new(argument_str).canonicalize() {
+        Ok(existing_path) => PathWithPosition::from_path(existing_path),
+        Err(_) => {
+            let path = PathWithPosition::parse_str(argument_str);
+            let curdir = env::current_dir().context("reteiving current directory")?;
+            path.map_path(|path| match fs::canonicalize(&path) {
+                Ok(path) => Ok(path),
+                Err(e) => {
+                    if let Some(mut parent) = path.parent() {
+                        if parent == Path::new("") {
+                            parent = &curdir
+                        }
+                        match fs::canonicalize(parent) {
+                            Ok(parent) => Ok(parent.join(path.file_name().unwrap())),
+                            Err(_) => Err(e),
+                        }
+                    } else {
+                        Err(e)
+                    }
+                }
+            })
+        }
+        .with_context(|| format!("parsing as path with position {argument_str}"))?,
+    };
+    Ok(canonicalized.to_string(|path| path.to_string_lossy().to_string()))
+}
+
+fn main() -> Result<()> {
+    // Exit flatpak sandbox if needed
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    {
+        flatpak::try_restart_to_host();
+        flatpak::ld_extra_libs();
+    }
+
+    // Intercept version designators
+    #[cfg(target_os = "macos")]
+    if let Some(channel) = std::env::args().nth(1).filter(|arg| arg.starts_with("--")) {
+        // When the first argument is a name of a release channel, we're gonna spawn off a cli of that version, with trailing args passed along.
+        use std::str::FromStr as _;
+
+        if let Ok(channel) = release_channel::ReleaseChannel::from_str(&channel[2..]) {
+            return mac_os::spawn_channel_cli(channel, std::env::args().skip(2).collect());
+        }
+    }
+    let args = Args::parse();
+
+    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
+    let args = flatpak::set_bin_if_no_escape(args);
+
+    let app = Detect::detect(args.zed.as_deref()).context("Bundle detection")?;
+
+    if args.version {
+        println!("{}", app.zed_version_string());
+        return Ok(());
+    }
+
+    let (server, server_name) =
+        IpcOneShotServer::<IpcHandshake>::new().context("Handshake before Zed spawn")?;
+    let url = format!("zed-cli://{server_name}");
+
+    let open_new_workspace = if args.new {
+        Some(true)
+    } else if args.add {
+        Some(false)
+    } else {
+        None
+    };
+
+    let env = Some(std::env::vars().collect::<HashMap<_, _>>());
+    let exit_status = Arc::new(Mutex::new(None));
+    let mut paths = vec![];
+    let mut urls = vec![];
+    let mut stdin_tmp_file: Option<fs::File> = None;
+    for path in args.paths_with_position.iter() {
+        if path.starts_with("zed://")
+            || path.starts_with("http://")
+            || path.starts_with("https://")
+            || path.starts_with("file://")
+            || path.starts_with("ssh://")
+        {
+            urls.push(path.to_string());
+        } else if path == "-" && args.paths_with_position.len() == 1 {
+            let file = NamedTempFile::new()?;
+            paths.push(file.path().to_string_lossy().to_string());
+            let (file, _) = file.keep()?;
+            stdin_tmp_file = Some(file);
+        } else {
+            paths.push(parse_path_with_position(path)?)
+        }
+    }
+
+    if let Some(_) = args.dev_server_token {
+        return Err(anyhow::anyhow!(
+            "Dev servers were removed in v0.157.x please upgrade to SSH remoting: https://zed.dev/docs/remote-development"
+        ))?;
+    }
+
+    let sender: JoinHandle<anyhow::Result<()>> = thread::spawn({
+        let exit_status = exit_status.clone();
+        move || {
+            let (_, handshake) = server.accept().context("Handshake after Zed spawn")?;
+            let (tx, rx) = (handshake.requests, handshake.responses);
+
+            tx.send(CliRequest::Open {
+                paths,
+                urls,
+                wait: args.wait,
+                open_new_workspace,
+                env,
+            })?;
+
+            while let Ok(response) = rx.recv() {
+                match response {
+                    CliResponse::Ping => {}
+                    CliResponse::Stdout { message } => println!("{message}"),
+                    CliResponse::Stderr { message } => eprintln!("{message}"),
+                    CliResponse::Exit { status } => {
+                        exit_status.lock().replace(status);
+                        return Ok(());
+                    }
+                }
+            }
+
+            Ok(())
+        }
+    });
+
+    let pipe_handle: JoinHandle<anyhow::Result<()>> = thread::spawn(move || {
+        if let Some(mut tmp_file) = stdin_tmp_file {
+            let mut stdin = std::io::stdin().lock();
+            if io::IsTerminal::is_terminal(&stdin) {
+                return Ok(());
+            }
+            let mut buffer = [0; 8 * 1024];
+            loop {
+                let bytes_read = io::Read::read(&mut stdin, &mut buffer)?;
+                if bytes_read == 0 {
+                    break;
+                }
+                io::Write::write(&mut tmp_file, &buffer[..bytes_read])?;
+            }
+            io::Write::flush(&mut tmp_file)?;
+        }
+        Ok(())
+    });
+
+    if args.foreground {
+        app.run_foreground(url)?;
+    } else {
+        app.launch(url)?;
+        sender.join().unwrap()?;
+        pipe_handle.join().unwrap()?;
+    }
+
+    if let Some(exit_status) = exit_status.lock().take() {
+        std::process::exit(exit_status);
+    }
+    Ok(())
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod linux {
+    use std::{
+        env,
+        ffi::OsString,
+        io,
+        os::unix::net::{SocketAddr, UnixDatagram},
+        path::{Path, PathBuf},
+        process::{self, ExitStatus},
+        thread,
+        time::Duration,
+    };
+
+    use anyhow::anyhow;
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+    use fork::Fork;
+    use once_cell::sync::Lazy;
+
+    use crate::{Detect, InstalledApp};
+
+    static RELEASE_CHANNEL: Lazy<String> =
+        Lazy::new(|| include_str!("../../zed/RELEASE_CHANNEL").trim().to_string());
+
+    struct App(PathBuf);
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let path = if let Some(path) = path {
+                path.to_path_buf().canonicalize()?
+            } else {
+                let cli = env::current_exe()?;
+                let dir = cli
+                    .parent()
+                    .ok_or_else(|| anyhow!("no parent path for cli"))?;
+
+                // libexec is the standard, lib/zed is for Arch (and other non-libexec distros),
+                // ./zed is for the target directory in development builds.
+                let possible_locations =
+                    ["../libexec/zed-editor", "../lib/zed/zed-editor", "./zed"];
+                possible_locations
+                    .iter()
+                    .find_map(|p| dir.join(p).canonicalize().ok().filter(|path| path != &cli))
+                    .ok_or_else(|| {
+                        anyhow!("could not find any of: {}", possible_locations.join(", "))
+                    })?
+            };
+
+            Ok(App(path))
+        }
+    }
+
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            format!(
+                "Zed {}{} – {}",
+                if *RELEASE_CHANNEL == "stable" {
+                    "".to_string()
+                } else {
+                    format!(" {} ", *RELEASE_CHANNEL)
+                },
+                option_env!("RELEASE_VERSION").unwrap_or_default(),
+                self.0.display(),
+            )
+        }
+
+        fn launch(&self, ipc_url: String) -> anyhow::Result<()> {
+            let sock_path = paths::support_dir().join(format!("zed-{}.sock", *RELEASE_CHANNEL));
+            let sock = UnixDatagram::unbound()?;
+            if sock.connect(&sock_path).is_err() {
+                self.boot_background(ipc_url)?;
+            } else {
+                sock.send(ipc_url.as_bytes())?;
+            }
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            std::process::Command::new(self.0.clone())
+                .arg(ipc_url)
+                .status()
+        }
+    }
+
+    impl App {
+        fn boot_background(&self, ipc_url: String) -> anyhow::Result<()> {
+            let path = &self.0;
+
+            match fork::fork() {
+                Ok(Fork::Parent(_)) => Ok(()),
+                Ok(Fork::Child) => {
+                    std::env::set_var(FORCE_CLI_MODE_ENV_VAR_NAME, "");
+                    if let Err(_) = fork::setsid() {
+                        eprintln!("failed to setsid: {}", std::io::Error::last_os_error());
+                        process::exit(1);
+                    }
+                    if let Err(_) = fork::close_fd() {
+                        eprintln!("failed to close_fd: {}", std::io::Error::last_os_error());
+                    }
+                    let error =
+                        exec::execvp(path.clone(), &[path.as_os_str(), &OsString::from(ipc_url)]);
+                    // if exec succeeded, we never get here.
+                    eprintln!("failed to exec {:?}: {}", path, error);
+                    process::exit(1)
+                }
+                Err(_) => Err(anyhow!(io::Error::last_os_error())),
+            }
+        }
+
+        fn wait_for_socket(
+            &self,
+            sock_addr: &SocketAddr,
+            sock: &mut UnixDatagram,
+        ) -> Result<(), std::io::Error> {
+            for _ in 0..100 {
+                thread::sleep(Duration::from_millis(10));
+                if sock.connect_addr(&sock_addr).is_ok() {
+                    return Ok(());
+                }
+            }
+            sock.connect_addr(&sock_addr)
+        }
+    }
+}
+
+#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+mod flatpak {
+    use std::ffi::OsString;
+    use std::path::PathBuf;
+    use std::process::Command;
+    use std::{env, process};
+
+    const EXTRA_LIB_ENV_NAME: &'static str = "ZED_FLATPAK_LIB_PATH";
+    const NO_ESCAPE_ENV_NAME: &'static str = "ZED_FLATPAK_NO_ESCAPE";
+
+    /// Adds bundled libraries to LD_LIBRARY_PATH if running under flatpak
+    pub fn ld_extra_libs() {
+        let mut paths = if let Ok(paths) = env::var("LD_LIBRARY_PATH") {
+            env::split_paths(&paths).collect()
+        } else {
+            Vec::new()
+        };
+
+        if let Ok(extra_path) = env::var(EXTRA_LIB_ENV_NAME) {
+            paths.push(extra_path.into());
+        }
+
+        env::set_var("LD_LIBRARY_PATH", env::join_paths(paths).unwrap());
+    }
+
+    /// Restarts outside of the sandbox if currently running within it
+    pub fn try_restart_to_host() {
+        if let Some(flatpak_dir) = get_flatpak_dir() {
+            let mut args = vec!["/usr/bin/flatpak-spawn".into(), "--host".into()];
+            args.append(&mut get_xdg_env_args());
+            args.push("--env=ZED_UPDATE_EXPLANATION=Please use flatpak to update zed".into());
+            args.push(
+                format!(
+                    "--env={EXTRA_LIB_ENV_NAME}={}",
+                    flatpak_dir.join("lib").to_str().unwrap()
+                )
+                .into(),
+            );
+            args.push(flatpak_dir.join("bin").join("zed").into());
+
+            let mut is_app_location_set = false;
+            for arg in &env::args_os().collect::<Vec<_>>()[1..] {
+                args.push(arg.clone());
+                is_app_location_set |= arg == "--zed";
+            }
+
+            if !is_app_location_set {
+                args.push("--zed".into());
+                args.push(flatpak_dir.join("libexec").join("zed-editor").into());
+            }
+
+            let error = exec::execvp("/usr/bin/flatpak-spawn", args);
+            eprintln!("failed restart cli on host: {:?}", error);
+            process::exit(1);
+        }
+    }
+
+    pub fn set_bin_if_no_escape(mut args: super::Args) -> super::Args {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok()
+            && env::var("FLATPAK_ID").map_or(false, |id| id.starts_with("dev.zed.Zed"))
+        {
+            if args.zed.is_none() {
+                args.zed = Some("/app/libexec/zed-editor".into());
+                env::set_var("ZED_UPDATE_EXPLANATION", "Please use flatpak to update zed");
+            }
+        }
+        args
+    }
+
+    fn get_flatpak_dir() -> Option<PathBuf> {
+        if env::var(NO_ESCAPE_ENV_NAME).is_ok() {
+            return None;
+        }
+
+        if let Ok(flatpak_id) = env::var("FLATPAK_ID") {
+            if !flatpak_id.starts_with("dev.zed.Zed") {
+                return None;
+            }
+
+            let install_dir = Command::new("/usr/bin/flatpak-spawn")
+                .arg("--host")
+                .arg("flatpak")
+                .arg("info")
+                .arg("--show-location")
+                .arg(flatpak_id)
+                .output()
+                .unwrap();
+            let install_dir = PathBuf::from(String::from_utf8(install_dir.stdout).unwrap().trim());
+            Some(install_dir.join("files"))
+        } else {
+            None
+        }
+    }
+
+    fn get_xdg_env_args() -> Vec<OsString> {
+        let xdg_keys = [
+            "XDG_DATA_HOME",
+            "XDG_CONFIG_HOME",
+            "XDG_CACHE_HOME",
+            "XDG_STATE_HOME",
+        ];
+        env::vars()
+            .filter(|(key, _)| xdg_keys.contains(&key.as_str()))
+            .map(|(key, val)| format!("--env=FLATPAK_{}={}", key, val).into())
+            .collect()
+    }
+}
+
+// todo("windows")
+#[cfg(target_os = "windows")]
+mod windows {
+    use crate::{Detect, InstalledApp};
+    use std::io;
+    use std::path::Path;
+    use std::process::ExitStatus;
+
+    struct App;
+    impl InstalledApp for App {
+        fn zed_version_string(&self) -> String {
+            unimplemented!()
+        }
+        fn launch(&self, _ipc_url: String) -> anyhow::Result<()> {
+            unimplemented!()
+        }
+        fn run_foreground(&self, _ipc_url: String) -> io::Result<ExitStatus> {
+            unimplemented!()
+        }
+    }
+
+    impl Detect {
+        pub fn detect(_path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            Ok(App)
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+mod mac_os {
+    use anyhow::{anyhow, Context, Result};
+    use core_foundation::{
+        array::{CFArray, CFIndex},
+        string::kCFStringEncodingUTF8,
+        url::{CFURLCreateWithBytes, CFURL},
+    };
+    use core_services::{kLSLaunchDefaults, LSLaunchURLSpec, LSOpenFromURLSpec, TCFType};
+    use serde::Deserialize;
+    use std::{
+        ffi::OsStr,
+        fs, io,
+        path::{Path, PathBuf},
+        process::{Command, ExitStatus},
+        ptr,
+    };
+
+    use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
+
+    use crate::{Detect, InstalledApp};
+
+    #[derive(Debug, Deserialize)]
+    struct InfoPlist {
+        #[serde(rename = "CFBundleShortVersionString")]
+        bundle_short_version_string: String,
+    }
+
+    enum Bundle {
+        App {
+            app_bundle: PathBuf,
+            plist: InfoPlist,
+        },
+        LocalPath {
+            executable: PathBuf,
+            plist: InfoPlist,
+        },
+    }
+
+    fn locate_bundle() -> Result<PathBuf> {
+        let cli_path = std::env::current_exe()?.canonicalize()?;
+        let mut app_path = cli_path.clone();
+        while app_path.extension() != Some(OsStr::new("app")) {
+            if !app_path.pop() {
+                return Err(anyhow!("cannot find app bundle containing {:?}", cli_path));
+            }
+        }
+        Ok(app_path)
+    }
+
+    impl Detect {
+        pub fn detect(path: Option<&Path>) -> anyhow::Result<impl InstalledApp> {
+            let bundle_path = if let Some(bundle_path) = path {
+                bundle_path
+                    .canonicalize()
+                    .with_context(|| format!("Args bundle path {bundle_path:?} canonicalization"))?
+            } else {
+                locate_bundle().context("bundle autodiscovery")?
+            };
+
+            match bundle_path.extension().and_then(|ext| ext.to_str()) {
+                Some("app") => {
+                    let plist_path = bundle_path.join("Contents/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading *.app bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::App {
+                        app_bundle: bundle_path,
+                        plist,
+                    })
+                }
+                _ => {
+                    println!("Bundle path {bundle_path:?} has no *.app extension, attempting to locate a dev build");
+                    let plist_path = bundle_path
+                        .parent()
+                        .with_context(|| format!("Bundle path {bundle_path:?} has no parent"))?
+                        .join("WebRTC.framework/Resources/Info.plist");
+                    let plist =
+                        plist::from_file::<_, InfoPlist>(&plist_path).with_context(|| {
+                            format!("Reading dev bundle plist file at {plist_path:?}")
+                        })?;
+                    Ok(Bundle::LocalPath {
+                        executable: bundle_path,
+                        plist,
+                    })
+                }
+            }
+        }
+    }
+
+    impl InstalledApp for Bundle {
+        fn zed_version_string(&self) -> String {
+            let is_dev = matches!(self, Self::LocalPath { .. });
+            format!(
+                "Zed {}{} – {}",
+                self.plist().bundle_short_version_string,
+                if is_dev { " (dev)" } else { "" },
+                self.path().display(),
+            )
+        }
+
+        fn launch(&self, url: String) -> anyhow::Result<()> {
+            match self {
+                Self::App { app_bundle, .. } => {
+                    let app_path = app_bundle;
+
+                    let status = unsafe {
+                        let app_url = CFURL::from_path(app_path, true)
+                            .with_context(|| format!("invalid app path {app_path:?}"))?;
+                        let url_to_open = CFURL::wrap_under_create_rule(CFURLCreateWithBytes(
+                            ptr::null(),
+                            url.as_ptr(),
+                            url.len() as CFIndex,
+                            kCFStringEncodingUTF8,
+                            ptr::null(),
+                        ));
+                        // equivalent to: open zed-cli:... -a /Applications/Zed\ Preview.app
+                        let urls_to_open =
+                            CFArray::from_copyable(&[url_to_open.as_concrete_TypeRef()]);
+                        LSOpenFromURLSpec(
+                            &LSLaunchURLSpec {
+                                appURL: app_url.as_concrete_TypeRef(),
+                                itemURLs: urls_to_open.as_concrete_TypeRef(),
+                                passThruParams: ptr::null(),
+                                launchFlags: kLSLaunchDefaults,
+                                asyncRefCon: ptr::null_mut(),
+                            },
+                            ptr::null_mut(),
+                        )
+                    };
+
+                    anyhow::ensure!(
+                        status == 0,
+                        "cannot start app bundle {}",
+                        self.zed_version_string()
+                    );
+                }
+
+                Self::LocalPath { executable, .. } => {
+                    let executable_parent = executable
+                        .parent()
+                        .with_context(|| format!("Executable {executable:?} path has no parent"))?;
+                    let subprocess_stdout_file = fs::File::create(
+                        executable_parent.join("zed_dev.log"),
+                    )
+                    .with_context(|| format!("Log file creation in {executable_parent:?}"))?;
+                    let subprocess_stdin_file =
+                        subprocess_stdout_file.try_clone().with_context(|| {
+                            format!("Cloning descriptor for file {subprocess_stdout_file:?}")
+                        })?;
+                    let mut command = std::process::Command::new(executable);
+                    let command = command
+                        .env(FORCE_CLI_MODE_ENV_VAR_NAME, "")
+                        .stderr(subprocess_stdout_file)
+                        .stdout(subprocess_stdin_file)
+                        .arg(url);
+
+                    command
+                        .spawn()
+                        .with_context(|| format!("Spawning {command:?}"))?;
+                }
+            }
+
+            Ok(())
+        }
+
+        fn run_foreground(&self, ipc_url: String) -> io::Result<ExitStatus> {
+            let path = match self {
+                Bundle::App { app_bundle, .. } => app_bundle.join("Contents/MacOS/zed"),
+                Bundle::LocalPath { executable, .. } => executable.clone(),
+            };
+
+            std::process::Command::new(path).arg(ipc_url).status()
+        }
+    }
+
+    impl Bundle {
+        fn plist(&self) -> &InfoPlist {
+            match self {
+                Self::App { plist, .. } => plist,
+                Self::LocalPath { plist, .. } => plist,
+            }
+        }
+
+        fn path(&self) -> &Path {
+            match self {
+                Self::App { app_bundle, .. } => app_bundle,
+                Self::LocalPath { executable, .. } => executable,
+            }
+        }
+    }
+
+    pub(super) fn spawn_channel_cli(
+        channel: release_channel::ReleaseChannel,
+        leftover_args: Vec<String>,
+    ) -> Result<()> {
+        use anyhow::bail;
+
+        let app_id_prompt = format!("id of app \"{}\"", channel.display_name());
+        let app_id_output = Command::new("osascript")
+            .arg("-e")
+            .arg(&app_id_prompt)
+            .output()?;
+        if !app_id_output.status.success() {
+            bail!("Could not determine app id for {}", channel.display_name());
+        }
+        let app_name = String::from_utf8(app_id_output.stdout)?.trim().to_owned();
+        let app_path_prompt = format!("kMDItemCFBundleIdentifier == '{app_name}'");
+        let app_path_output = Command::new("mdfind").arg(app_path_prompt).output()?;
+        if !app_path_output.status.success() {
+            bail!(
+                "Could not determine app path for {}",
+                channel.display_name()
+            );
+        }
+        let app_path = String::from_utf8(app_path_output.stdout)?.trim().to_owned();
+        let cli_path = format!("{app_path}/Contents/MacOS/cli");
+        Command::new(cli_path).args(leftover_args).spawn()?;
+        Ok(())
+    }
+}

crates/zeta/src/complete_prompt.md

@@ -0,0 +1,12 @@
+Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
+
+### Instruction:
+You are a code completion assistant and your task is to analyze user edits and then rewrite an excerpt that the user provides, suggesting the appropriate edits within the excerpt, taking into account the cursor location.
+
+### Events:
+<events>
+
+### Input:
+<excerpt>
+
+### Response:

crates/zeta/src/eval_prompt.md

@@ -0,0 +1,20 @@
+Your task is to help me grade code test output.
+
+Here is the test output:
+
+```
+<actual>
+```
+
+Now, help me score the test output using the following criteria:
+
+<assertions>
+
+Based on these criteria, give the test output a score between 0 and 5.
+
+- 0 means: test output doesn't meet any criteria
+- 5 means: test output meets all criteria
+- If the test output does not contain any of the text I said it "must" include, grade it 0.
+- First, perform a short, succinct analysis of how the test output meets the criteria.
+- On the last line of your response, write the grade as a single number. Nothing else.
+- **Always** end with a grade. The last line **must** be a number between 0 and 5.