kaish_kernel/ast/
sexpr.rs

1//! S-expression formatter for kaish AST.
2//!
3//! Converts AST nodes to the S-expression format used in test snapshots.
4//! S-expressions provide a stable, readable format that's easier to diff
5//! than Debug output.
6
7use super::*;
8
9/// Format a Program as an S-expression.
10/// For single-statement programs, formats just the statement.
11/// For multi-statement programs, formats as a sequence.
12pub fn format_program(program: &Program) -> String {
13    let stmts: Vec<_> = program
14        .statements
15        .iter()
16        .filter(|s| !matches!(s, Stmt::Empty))
17        .collect();
18
19    match stmts.len() {
20        0 => "(program)".to_string(),
21        1 => format_stmt(stmts[0]),
22        _ => {
23            let parts: Vec<String> = stmts.iter().map(|s| format_stmt(s)).collect();
24            format!("(program {})", parts.join(" "))
25        }
26    }
27}
28
29/// Format a statement as an S-expression.
30pub fn format_stmt(stmt: &Stmt) -> String {
31    match stmt {
32        Stmt::Assignment(a) => format_assignment(a),
33        Stmt::Command(cmd) => format_command(cmd),
34        Stmt::Pipeline(p) => format_pipeline(p),
35        Stmt::If(if_stmt) => format_if(if_stmt),
36        Stmt::For(for_loop) => format_for(for_loop),
37        Stmt::While(while_loop) => format_while(while_loop),
38        Stmt::Case(case_stmt) => format_case(case_stmt),
39        Stmt::Break(n) => match n {
40            Some(level) => format!("(break {})", level),
41            None => "(break)".to_string(),
42        },
43        Stmt::Continue(n) => match n {
44            Some(level) => format!("(continue {})", level),
45            None => "(continue)".to_string(),
46        },
47        Stmt::Return(expr) => match expr {
48            Some(e) => format!("(return {})", format_expr(e)),
49            None => "(return)".to_string(),
50        },
51        Stmt::Exit(expr) => match expr {
52            Some(e) => format!("(exit {})", format_expr(e)),
53            None => "(exit)".to_string(),
54        },
55        Stmt::ToolDef(tool) => format_tooldef(tool),
56        Stmt::Test(test_expr) => format!("(test {})", format_test_expr(test_expr)),
57        Stmt::AndChain { left, right } => {
58            format!("(and-chain {} {})", format_stmt(left), format_stmt(right))
59        }
60        Stmt::OrChain { left, right } => {
61            format!("(or-chain {} {})", format_stmt(left), format_stmt(right))
62        }
63        Stmt::Empty => "(empty)".to_string(),
64    }
65}
66
67/// Format an assignment as an S-expression.
68fn format_assignment(a: &Assignment) -> String {
69    let value = format_expr(&a.value);
70    format!("(assign {} {} local={})", a.name, value, a.local)
71}
72
73/// Format a command as an S-expression.
74pub fn format_command(cmd: &Command) -> String {
75    let mut parts = vec![format!("(cmd {}", cmd.name)];
76
77    for arg in &cmd.args {
78        parts.push(format_arg(arg));
79    }
80
81    for redir in &cmd.redirects {
82        parts.push(format_redirect(redir));
83    }
84
85    format!("{})", parts.join(" "))
86}
87
88/// Format an argument as an S-expression.
89fn format_arg(arg: &Arg) -> String {
90    match arg {
91        Arg::Positional(expr) => format!("(pos {})", format_expr(expr)),
92        Arg::Named { key, value } => format!("(named {} {})", key, format_expr(value)),
93        Arg::ShortFlag(f) => format!("(shortflag {})", f),
94        Arg::LongFlag(f) => format!("(longflag {})", f),
95        Arg::DoubleDash => "(doubledash)".to_string(),
96    }
97}
98
99/// Format a redirect as an S-expression.
100fn format_redirect(redir: &Redirect) -> String {
101    let kind = match redir.kind {
102        RedirectKind::StdoutOverwrite => ">",
103        RedirectKind::StdoutAppend => ">>",
104        RedirectKind::Stdin => "<",
105        RedirectKind::HereDoc => "<<",
106        RedirectKind::Stderr => "2>",
107        RedirectKind::Both => "&>",
108        RedirectKind::MergeStderr => "2>&1",
109        RedirectKind::MergeStdout => "1>&2",
110    };
111    format!("(redir {} {})", kind, format_expr(&redir.target))
112}
113
114/// Format a pipeline as an S-expression.
115pub fn format_pipeline(p: &Pipeline) -> String {
116    let cmds: Vec<String> = p.commands.iter().map(format_command).collect();
117
118    if p.background {
119        if cmds.len() == 1 {
120            format!("(background {})", cmds[0])
121        } else {
122            format!("(background (pipeline {}))", cmds.join(" "))
123        }
124    } else {
125        format!("(pipeline {})", cmds.join(" "))
126    }
127}
128
129/// Format an if statement as an S-expression.
130fn format_if(if_stmt: &IfStmt) -> String {
131    let cond = format_expr(&if_stmt.condition);
132    let then_stmts: Vec<String> = if_stmt
133        .then_branch
134        .iter()
135        .filter(|s| !matches!(s, Stmt::Empty))
136        .map(format_stmt)
137        .collect();
138    let then_part = format!("(then {})", then_stmts.join(" "));
139
140    match &if_stmt.else_branch {
141        Some(else_stmts) => {
142            let else_inner: Vec<String> = else_stmts
143                .iter()
144                .filter(|s| !matches!(s, Stmt::Empty))
145                .map(format_stmt)
146                .collect();
147            if else_inner.is_empty() {
148                format!("(if {} {} (else))", cond, then_part)
149            } else {
150                format!("(if {} {} (else {}))", cond, then_part, else_inner.join(" "))
151            }
152        }
153        None => format!("(if {} {} (else))", cond, then_part),
154    }
155}
156
157/// Format a for loop as an S-expression.
158fn format_for(for_loop: &ForLoop) -> String {
159    let items: Vec<String> = for_loop.items.iter().map(format_expr).collect();
160    let body_stmts: Vec<String> = for_loop
161        .body
162        .iter()
163        .filter(|s| !matches!(s, Stmt::Empty))
164        .map(format_stmt)
165        .collect();
166    format!(
167        "(for {} (in {}) (do {}))",
168        for_loop.variable,
169        items.join(" "),
170        body_stmts.join(" ")
171    )
172}
173
174/// Format a while loop as an S-expression.
175fn format_while(while_loop: &WhileLoop) -> String {
176    let cond = format_expr(&while_loop.condition);
177    let body_stmts: Vec<String> = while_loop
178        .body
179        .iter()
180        .filter(|s| !matches!(s, Stmt::Empty))
181        .map(format_stmt)
182        .collect();
183    format!("(while {} (do {}))", cond, body_stmts.join(" "))
184}
185
186/// Format a case statement as an S-expression.
187fn format_case(case_stmt: &CaseStmt) -> String {
188    let expr = format_expr(&case_stmt.expr);
189    let branches: Vec<String> = case_stmt
190        .branches
191        .iter()
192        .map(format_case_branch)
193        .collect();
194    format!("(case {} ({}))", expr, branches.join(" "))
195}
196
197/// Format a case branch as an S-expression.
198fn format_case_branch(branch: &CaseBranch) -> String {
199    let patterns = branch.patterns.join("|");
200    let body_stmts: Vec<String> = branch
201        .body
202        .iter()
203        .filter(|s| !matches!(s, Stmt::Empty))
204        .map(format_stmt)
205        .collect();
206    format!("(branch \"{}\" ({}))", patterns, body_stmts.join(" "))
207}
208
209/// Format a tool definition as an S-expression.
210fn format_tooldef(tool: &ToolDef) -> String {
211    let params: Vec<String> = tool.params.iter().map(format_param).collect();
212    let body_stmts: Vec<String> = tool
213        .body
214        .iter()
215        .filter(|s| !matches!(s, Stmt::Empty))
216        .map(format_stmt)
217        .collect();
218    format!(
219        "(tooldef {} ({}) ({}))",
220        tool.name,
221        params.join(" "),
222        body_stmts.join(" ")
223    )
224}
225
226/// Format a parameter definition as an S-expression.
227fn format_param(param: &ParamDef) -> String {
228    let type_str = param
229        .param_type
230        .as_ref()
231        .map(|t| match t {
232            ParamType::String => "string",
233            ParamType::Int => "int",
234            ParamType::Float => "float",
235            ParamType::Bool => "bool",
236        })
237        .unwrap_or("any");
238
239    match &param.default {
240        Some(default) => format!("(param {} {} {})", param.name, type_str, format_expr(default)),
241        None => format!("(param {} {})", param.name, type_str),
242    }
243}
244
245/// Format an expression as an S-expression.
246pub fn format_expr(expr: &Expr) -> String {
247    match expr {
248        Expr::Literal(value) => format_value(value),
249        Expr::VarRef(path) => format!("(varref {})", format_varpath(path)),
250        Expr::Interpolated(parts) => {
251            let parts_str: Vec<String> = parts
252                .iter()
253                .map(format_string_part)
254                .collect();
255            format!("(interpolated {})", parts_str.join(" "))
256        }
257        Expr::BinaryOp { left, op, right } => {
258            let op_str = match op {
259                BinaryOp::And => "and",
260                BinaryOp::Or => "or",
261                BinaryOp::Eq => "eq",
262                BinaryOp::NotEq => "neq",
263                BinaryOp::Match => "match",
264                BinaryOp::NotMatch => "not-match",
265                BinaryOp::Lt => "<",
266                BinaryOp::Gt => ">",
267                BinaryOp::LtEq => "<=",
268                BinaryOp::GtEq => ">=",
269            };
270            format!("({} {} {})", op_str, format_expr(left), format_expr(right))
271        }
272        Expr::CommandSubst(pipeline) => {
273            format!("(cmdsubst {})", format_pipeline(pipeline))
274        }
275        Expr::Test(test_expr) => format!("(test {})", format_test_expr(test_expr)),
276        Expr::Positional(n) => format!("(positional {})", n),
277        Expr::AllArgs => "(all-args)".to_string(),
278        Expr::ArgCount => "(arg-count)".to_string(),
279        Expr::VarLength(name) => format!("(var-length {})", name),
280        Expr::VarWithDefault { name, default } => {
281            let default_parts: Vec<String> = default.iter().map(format_string_part).collect();
282            format!("(var-default {} ({}))", name, default_parts.join(" "))
283        }
284        Expr::Arithmetic(expr_str) => format!("(arithmetic \"{}\")", expr_str),
285        Expr::Command(cmd) => format_command(cmd),
286        Expr::LastExitCode => "(last-exit-code)".to_string(),
287        Expr::CurrentPid => "(current-pid)".to_string(),
288    }
289}
290
291/// Format a test expression as an S-expression.
292pub fn format_test_expr(test: &TestExpr) -> String {
293    match test {
294        TestExpr::FileTest { op, path } => {
295            let op_str = match op {
296                FileTestOp::Exists => "-e",
297                FileTestOp::IsFile => "-f",
298                FileTestOp::IsDir => "-d",
299                FileTestOp::Readable => "-r",
300                FileTestOp::Writable => "-w",
301                FileTestOp::Executable => "-x",
302            };
303            format!("(file {} {})", op_str, format_expr(path))
304        }
305        TestExpr::StringTest { op, value } => {
306            let op_str = match op {
307                StringTestOp::IsEmpty => "-z",
308                StringTestOp::IsNonEmpty => "-n",
309            };
310            format!("(string {} {})", op_str, format_expr(value))
311        }
312        TestExpr::Comparison { left, op, right } => {
313            let op_str = match op {
314                TestCmpOp::Eq => "==",
315                TestCmpOp::NotEq => "!=",
316                TestCmpOp::Match => "=~",
317                TestCmpOp::NotMatch => "!~",
318                TestCmpOp::Gt => "-gt",
319                TestCmpOp::Lt => "-lt",
320                TestCmpOp::GtEq => "-ge",
321                TestCmpOp::LtEq => "-le",
322            };
323            format!(
324                "(cmp {} {} {})",
325                op_str,
326                format_expr(left),
327                format_expr(right)
328            )
329        }
330        TestExpr::And { left, right } => {
331            format!("(and {} {})", format_test_expr(left), format_test_expr(right))
332        }
333        TestExpr::Or { left, right } => {
334            format!("(or {} {})", format_test_expr(left), format_test_expr(right))
335        }
336        TestExpr::Not { expr } => {
337            format!("(not {})", format_test_expr(expr))
338        }
339    }
340}
341
342/// Format a StringPart as an S-expression.
343fn format_string_part(part: &StringPart) -> String {
344    match part {
345        StringPart::Literal(s) => format!("\"{}\"", escape_for_display(s)),
346        StringPart::Var(path) => format!("(varref {})", format_varpath(path)),
347        StringPart::VarWithDefault { name, default } => {
348            let default_parts: Vec<String> = default.iter().map(format_string_part).collect();
349            format!("(vardefault {} ({}))", name, default_parts.join(" "))
350        }
351        StringPart::VarLength(name) => format!("(varlength {})", name),
352        StringPart::Positional(n) => format!("(positional {})", n),
353        StringPart::AllArgs => "(allargs)".to_string(),
354        StringPart::ArgCount => "(argcount)".to_string(),
355        StringPart::Arithmetic(expr) => format!("(arith \"{}\")", expr),
356        StringPart::CommandSubst(pipeline) => format!("(cmdsubst {})", format_pipeline(pipeline)),
357        StringPart::LastExitCode => "(last-exit-code)".to_string(),
358        StringPart::CurrentPid => "(current-pid)".to_string(),
359    }
360}
361
362/// Escape control characters for display in test output.
363fn escape_for_display(s: &str) -> String {
364    s.replace('\n', "\\n")
365        .replace('\t', "\\t")
366        .replace('\r', "\\r")
367}
368
369/// Format a value as an S-expression.
370pub fn format_value(value: &Value) -> String {
371    match value {
372        Value::Null => "(null)".to_string(),
373        Value::Bool(b) => format!("(bool {})", b),
374        Value::Int(n) => format!("(int {})", n),
375        Value::Float(f) => format!("(float {})", f),
376        Value::String(s) => format!("(string \"{}\")", escape_for_display(s)),
377        Value::Json(json) => format!("(json {})", json),
378        Value::Blob(blob) => format!("(blob id={} size={} type={})", blob.id, blob.size, blob.content_type),
379    }
380}
381
382/// Format a variable path as an S-expression.
383pub fn format_varpath(path: &VarPath) -> String {
384    path.segments
385        .iter()
386        .map(|seg| match seg {
387            VarSegment::Field(name) => name.clone(),
388        })
389        .collect::<Vec<_>>()
390        .join(".")
391}
392
393#[cfg(test)]
394mod tests {
395    use super::*;
396
397    #[test]
398    fn format_simple_int() {
399        assert_eq!(format_value(&Value::Int(42)), "(int 42)");
400    }
401
402    #[test]
403    fn format_simple_string() {
404        assert_eq!(format_value(&Value::String("hello".to_string())), "(string \"hello\")");
405    }
406
407    #[test]
408    fn format_varpath_simple() {
409        let path = VarPath::simple("X");
410        assert_eq!(format_varpath(&path), "X");
411    }
412
413    #[test]
414    fn format_varpath_nested() {
415        let path = VarPath {
416            segments: vec![
417                VarSegment::Field("VAR".to_string()),
418                VarSegment::Field("field".to_string()),
419            ],
420        };
421        assert_eq!(format_varpath(&path), "VAR.field");
422    }
423}
kaish_kernel/ast/sexpr.rs

kaish_kernel/ast/
sexpr.rs
