feat: Emit keyword

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

@@ -36,6 +36,14 @@ pub fn parser<'a>(
                 then: Box::new(then_.unwrap_or_else(|| UntypedExpr::todo(None, span))),
                 text: Box::new(text),
             }),
+        just(Token::Emit)
+            .ignore_then(choice((string::hybrid(), expression.clone())))
+            .then(sequence.clone().or_not())
+            .map_with_span(|(text, then_), span| UntypedExpr::Emit {
+                location: span,
+                then: Box::new(then_.unwrap_or_else(|| UntypedExpr::todo(None, span))),
+                text: Box::new(text),
+            }),
     ))
 }
 

crates/aiken-lang/src/parser/lexer.rs

@@ -220,6 +220,7 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
 
     let keyword = text::ident().map(|s: String| match s.as_str() {
         "trace" => Token::Trace,
+        "emit" => Token::Emit,
         // TODO: remove this in a future release
         "error" => Token::Fail,
         "fail" => Token::Fail,

crates/aiken-lang/src/parser/token.rs

@@ -89,6 +89,7 @@ pub enum Token {
     Type,
     When,
     Trace,
+    Emit,
     Validator,
     Via,
 }
@@ -175,6 +176,7 @@ impl fmt::Display for Token {
             Token::Pub => "pub",
             Token::Todo => "todo",
             Token::Trace => "trace",
+            Token::Emit => "emit",
             Token::Type => "type",
             Token::Test => "test",
             Token::Fail => "fail",