Allow variadic arguments in trace

Although, doesn't do anything with them yet. The idea is to simplify
  the use of trace to make it a lot more useful than it currently is.

crates/aiken-lang/src/expr.rs

@@ -548,7 +548,8 @@ pub enum UntypedExpr {
         kind: TraceKind,
         location: Span,
         then: Box<Self>,
-        text: Box<Self>,
+        label: Box<Self>,
+        arguments: Vec<Self>,
     },
 
     TraceIfFalse {
@@ -1134,10 +1135,11 @@ impl UntypedExpr {
             location,
             kind: TraceKind::Todo,
             then: Box::new(UntypedExpr::ErrorTerm { location }),
-            text: Box::new(reason.unwrap_or_else(|| UntypedExpr::String {
+            label: Box::new(reason.unwrap_or_else(|| UntypedExpr::String {
                 location,
                 value: DEFAULT_TODO_STR.to_string(),
             })),
+            arguments: Vec::new(),
         }
     }
 
@@ -1147,7 +1149,8 @@ impl UntypedExpr {
                 location,
                 kind: TraceKind::Error,
                 then: Box::new(UntypedExpr::ErrorTerm { location }),
-                text: Box::new(reason),
+                label: Box::new(reason),
+                arguments: Vec::new(),
             }
         } else {
             UntypedExpr::ErrorTerm { location }

crates/aiken-lang/src/format.rs

@@ -969,8 +969,12 @@ impl<'comments> Formatter<'comments> {
             } => self.assignment(patterns, value, *kind),
 
             UntypedExpr::Trace {
-                kind, text, then, ..
+                kind,
-            } => self.trace(kind, text, then),
+                label,
+                then,
+                arguments,
+                ..
+            } => self.trace(kind, label, arguments, then),
 
             UntypedExpr::When {
                 subject, clauses, ..
@@ -1037,26 +1041,34 @@ impl<'comments> Formatter<'comments> {
     pub fn trace<'a>(
         &mut self,
         kind: &'a TraceKind,
-        text: &'a UntypedExpr,
+        label: &'a UntypedExpr,
+        arguments: &'a [UntypedExpr],
         then: &'a UntypedExpr,
     ) -> Document<'a> {
-        let (keyword, default_text) = match kind {
+        let (keyword, default_label) = match kind {
             TraceKind::Trace => ("trace", None),
             TraceKind::Error => ("fail", Some(DEFAULT_ERROR_STR.to_string())),
             TraceKind::Todo => ("todo", Some(DEFAULT_TODO_STR.to_string())),
         };
 
-        let body = match text {
+        let mut body = match label {
-            UntypedExpr::String { value, .. } if Some(value) == default_text.as_ref() => {
+            UntypedExpr::String { value, .. } if Some(value) == default_label.as_ref() => {
                 keyword.to_doc()
             }
             _ => keyword
                 .to_doc()
                 .append(" ")
-                .append(self.wrap_expr(text))
+                .append(self.wrap_expr(label))
                 .group(),
         };
 
+        for (ix, arg) in arguments.iter().enumerate() {
+            body = body
+                .append(if ix == 0 { ": " } else { ", " })
+                .append(self.wrap_expr(arg))
+                .group();
+        }
+
         match kind {
             TraceKind::Error | TraceKind::Todo => body,
             TraceKind::Trace => body
@@ -1095,7 +1107,6 @@ impl<'comments> Formatter<'comments> {
         if args.is_empty() && spread_location.is_some() {
             if is_record {
                 name.append(" { .. }")
-            // TODO: not possible
             } else {
                 name.append("(..)")
             }

crates/aiken-lang/src/parser/definition/snapshots/function_empty.snap

@@ -11,10 +11,11 @@ Fn(
             then: ErrorTerm {
                 location: 0..15,
             },
-            text: String {
+            label: String {
                 location: 0..15,
                 value: "aiken::todo",
             },
+            arguments: [],
         },
         doc: None,
         location: 0..12,

crates/aiken-lang/src/parser/definition/snapshots/function_non_public.snap

@@ -11,10 +11,11 @@ Fn(
             then: ErrorTerm {
                 location: 0..11,
             },
-            text: String {
+            label: String {
                 location: 0..11,
                 value: "aiken::todo",
             },
+            arguments: [],
         },
         doc: None,
         location: 0..8,

crates/aiken-lang/src/parser/expr/fail_todo_trace.rs

@@ -28,13 +28,25 @@ pub fn parser<'a>(
             .map_with_span(UntypedExpr::fail),
         just(Token::Trace)
             .ignore_then(choice((string::hybrid(), expression.clone())))
+            .then(
+                just(Token::Colon)
+                    .ignore_then(
+                        choice((string::hybrid(), expression.clone()))
+                            .separated_by(just(Token::Comma)),
+                    )
+                    .or_not()
+                    .map(|opt| opt.unwrap_or_default()),
+            )
             .then(sequence.clone().or_not())
-            .map_with_span(|(text, then_), span| UntypedExpr::Trace {
+            .map_with_span(
-                kind: TraceKind::Trace,
+                |((label, arguments), continuation), span| UntypedExpr::Trace {
-                location: span,
+                    kind: TraceKind::Trace,
-                then: Box::new(then_.unwrap_or_else(|| UntypedExpr::todo(None, span))),
+                    location: span,
-                text: Box::new(text),
+                    then: Box::new(continuation.unwrap_or_else(|| UntypedExpr::todo(None, span))),
-            }),
+                    label: Box::new(label),
+                    arguments,
+                },
+            ),
     ))
 }
 
@@ -114,6 +126,26 @@ mod tests {
         );
     }
 
+    #[test]
+    fn trace_string() {
+        assert_expr!(
+            r#"
+            trace @"foo"
+            a
+            "#
+        );
+    }
+
+    #[test]
+    fn trace_bytearray() {
+        assert_expr!(
+            r#"
+            trace "foo"
+            a
+            "#
+        );
+    }
+
     #[test]
     fn trace_expr() {
         assert_expr!(
@@ -132,4 +164,22 @@ mod tests {
             "#
         );
     }
+
+    #[test]
+    fn trace_labelled() {
+        assert_expr!(
+            r#"
+            trace foo: "bar"
+            "#
+        );
+    }
+
+    #[test]
+    fn trace_variadic() {
+        assert_expr!(
+            r#"
+            trace "foo": @"bar", baz
+            "#
+        );
+    }
 }

crates/aiken-lang/src/parser/expr/snapshots/error_basic.snap

@@ -8,8 +8,9 @@ Trace {
     then: ErrorTerm {
         location: 0..11,
     },
-    text: String {
+    label: String {
         location: 5..11,
         value: "foo",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/error_sugar.snap

@@ -8,8 +8,9 @@ Trace {
     then: ErrorTerm {
         location: 0..10,
     },
-    text: String {
+    label: String {
         location: 5..10,
         value: "foo",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/fail_expr.snap

@@ -8,7 +8,7 @@ Trace {
     then: ErrorTerm {
         location: 0..67,
     },
-    text: Call {
+    label: Call {
         arguments: [
             CallArg {
                 label: None,
@@ -51,4 +51,5 @@ Trace {
         },
         location: 5..67,
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/if_soft_cast_discard_assign.snap

@@ -20,10 +20,11 @@ If {
                 then: ErrorTerm {
                     location: 20..24,
                 },
-                text: String {
+                label: String {
                     location: 20..24,
                     value: "aiken::todo",
                 },
+                arguments: [],
             },
             is: Some(
                 AssignmentPattern {
@@ -51,9 +52,10 @@ If {
         then: ErrorTerm {
             location: 36..40,
         },
-        text: String {
+        label: String {
             location: 36..40,
             value: "aiken::todo",
         },
+        arguments: [],
     },
 }

crates/aiken-lang/src/parser/expr/snapshots/if_soft_cast_not_var_condition.snap

@@ -20,10 +20,11 @@ If {
                 then: ErrorTerm {
                     location: 31..35,
                 },
-                text: String {
+                label: String {
                     location: 31..35,
                     value: "aiken::todo",
                 },
+                arguments: [],
             },
             is: Some(
                 AssignmentPattern {
@@ -68,9 +69,10 @@ If {
         then: ErrorTerm {
             location: 47..51,
         },
-        text: String {
+        label: String {
             location: 47..51,
             value: "aiken::todo",
         },
+        arguments: [],
     },
 }

crates/aiken-lang/src/parser/expr/snapshots/todo_basic.snap

@@ -8,8 +8,9 @@ Trace {
     then: ErrorTerm {
         location: 0..11,
     },
-    text: String {
+    label: String {
         location: 5..11,
         value: "foo",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/todo_empty.snap

@@ -8,8 +8,9 @@ Trace {
     then: ErrorTerm {
         location: 0..4,
     },
-    text: String {
+    label: String {
         location: 0..4,
         value: "aiken::todo",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/todo_expr.snap

@@ -8,7 +8,7 @@ Trace {
     then: ErrorTerm {
         location: 0..32,
     },
-    text: Call {
+    label: Call {
         arguments: [
             CallArg {
                 label: None,
@@ -49,4 +49,5 @@ Trace {
         },
         location: 5..32,
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/todo_sugar.snap

@@ -8,8 +8,9 @@ Trace {
     then: ErrorTerm {
         location: 0..10,
     },
-    text: String {
+    label: String {
         location: 5..10,
         value: "foo",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/trace_bytearray.snap

@@ -0,0 +1,17 @@
+---
+source: crates/aiken-lang/src/parser/expr/fail_todo_trace.rs
+description: "Code:\n\ntrace \"foo\"\na\n"
+---
+Trace {
+    kind: Trace,
+    location: 0..13,
+    then: Var {
+        location: 12..13,
+        name: "a",
+    },
+    label: String {
+        location: 6..11,
+        value: "foo",
+    },
+    arguments: [],
+}

crates/aiken-lang/src/parser/expr/snapshots/trace_expr.snap

@@ -9,7 +9,7 @@ Trace {
         location: 34..35,
         name: "a",
     },
-    text: Call {
+    label: Call {
         arguments: [
             CallArg {
                 label: None,
@@ -50,4 +50,5 @@ Trace {
         },
         location: 6..33,
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/trace_expr_todo.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/aiken-lang/src/parser/expr/fail_todo_trace.rs
-description: "Code:\n\ntrace some_var \n"
+description: "Code:\n\ntrace some_var\n"
 ---
 Trace {
     kind: Trace,
@@ -11,13 +11,15 @@ Trace {
         then: ErrorTerm {
             location: 0..14,
         },
-        text: String {
+        label: String {
             location: 0..14,
             value: "aiken::todo",
         },
+        arguments: [],
     },
-    text: Var {
+    label: Var {
         location: 6..14,
         name: "some_var",
     },
+    arguments: [],
 }

crates/aiken-lang/src/parser/expr/snapshots/trace_labelled.snap

@@ -0,0 +1,30 @@
+---
+source: crates/aiken-lang/src/parser/expr/fail_todo_trace.rs
+description: "Code:\n\ntrace foo: \"bar\"\n"
+---
+Trace {
+    kind: Trace,
+    location: 0..16,
+    then: Trace {
+        kind: Todo,
+        location: 0..16,
+        then: ErrorTerm {
+            location: 0..16,
+        },
+        label: String {
+            location: 0..16,
+            value: "aiken::todo",
+        },
+        arguments: [],
+    },
+    label: Var {
+        location: 6..9,
+        name: "foo",
+    },
+    arguments: [
+        String {
+            location: 11..16,
+            value: "bar",
+        },
+    ],
+}

crates/aiken-lang/src/parser/expr/snapshots/trace_string.snap

@@ -0,0 +1,17 @@
+---
+source: crates/aiken-lang/src/parser/expr/fail_todo_trace.rs
+description: "Code:\n\ntrace @\"foo\"\na\n"
+---
+Trace {
+    kind: Trace,
+    location: 0..14,
+    then: Var {
+        location: 13..14,
+        name: "a",
+    },
+    label: String {
+        location: 6..12,
+        value: "foo",
+    },
+    arguments: [],
+}

crates/aiken-lang/src/parser/expr/snapshots/trace_variadic.snap

@@ -0,0 +1,34 @@
+---
+source: crates/aiken-lang/src/parser/expr/fail_todo_trace.rs
+description: "Code:\n\ntrace \"foo\": @\"bar\", baz\n"
+---
+Trace {
+    kind: Trace,
+    location: 0..24,
+    then: Trace {
+        kind: Todo,
+        location: 0..24,
+        then: ErrorTerm {
+            location: 0..24,
+        },
+        label: String {
+            location: 0..24,
+            value: "aiken::todo",
+        },
+        arguments: [],
+    },
+    label: String {
+        location: 6..11,
+        value: "foo",
+    },
+    arguments: [
+        String {
+            location: 13..19,
+            value: "bar",
+        },
+        Var {
+            location: 21..24,
+            name: "baz",
+        },
+    ],
+}

crates/aiken-lang/src/parser/expr/when/snapshots/when_clause_double_todo.snap

@@ -32,10 +32,11 @@ When {
                 then: ErrorTerm {
                     location: 28..32,
                 },
-                text: String {
+                label: String {
                     location: 28..32,
                     value: "aiken::todo",
                 },
+                arguments: [],
             },
         },
         UntypedClause {
@@ -61,10 +62,11 @@ When {
                 then: ErrorTerm {
                     location: 47..51,
                 },
-                text: String {
+                label: String {
                     location: 47..51,
                     value: "aiken::todo",
                 },
+                arguments: [],
             },
         },
     ],

crates/aiken-lang/src/parser/expr/when/snapshots/when_clause_todo.snap

@@ -54,10 +54,11 @@ When {
                 then: ErrorTerm {
                     location: 47..68,
                 },
-                text: String {
+                label: String {
                     location: 52..68,
                     value: "unimplemented",
                 },
+                arguments: [],
             },
         },
     ],

crates/aiken-lang/src/tests/format.rs

@@ -985,3 +985,18 @@ fn format_validator_pattern() {
         "#
     );
 }
+
+#[test]
+fn format_variadic_trace() {
+    assert_format!(
+        r#"
+        fn foo() {
+            trace @"foo": @"bar"
+            trace "foo": "bar"
+            trace @"foo": "bar", @"baz"
+            trace bar: @"baz"
+            Void
+        }
+        "#
+    );
+}

crates/aiken-lang/src/tests/snapshots/format_variadic_trace.snap

@@ -0,0 +1,11 @@
+---
+source: crates/aiken-lang/src/tests/format.rs
+description: "Code:\n\nfn foo() {\n    trace @\"foo\": @\"bar\"\n    trace \"foo\": \"bar\"\n    trace @\"foo\": \"bar\", @\"baz\"\n    trace bar: @\"baz\"\n    Void\n}\n"
+---
+fn foo() {
+  trace @"foo": @"bar"
+  trace @"foo": @"bar"
+  trace @"foo": @"bar", @"baz"
+  trace bar: @"baz"
+  Void
+}

crates/aiken-lang/src/tipo/expr.rs

@@ -513,12 +513,14 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
                 self.infer_assignment(pattern, *value, kind, &annotation, location)
             }
 
+            // TODO: Trace.arguments
             UntypedExpr::Trace {
                 location,
                 then,
-                text,
+                label,
                 kind,
-            } => self.infer_trace(kind, *then, location, *text),
+                ..
+            } => self.infer_trace(kind, *then, location, *label),
 
             UntypedExpr::When {
                 location,