feat: some new features

- tuples `#(Int, Int)`
- `trace` and `trace("text")`

crates/lang/src/parser/error.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, fmt};
+use std::collections::HashSet;
 
 use miette::Diagnostic;
 
@@ -72,7 +72,7 @@ pub enum ErrorKind {
     #[error("unexpected end")]
     UnexpectedEnd,
     #[error("unexpected {0}")]
-    #[diagnostic(help("try removing it"))]
+    #[diagnostic(help("{}", .0.help().unwrap_or_else(|| Box::new(""))))]
     Unexpected(Pattern),
     #[error("unclosed {start}")]
     Unclosed {
@@ -87,12 +87,22 @@ pub enum ErrorKind {
 
 #[derive(Debug, PartialEq, Eq, Hash, Diagnostic, thiserror::Error)]
 pub enum Pattern {
+    #[error("{0:?}")]
     Char(char),
+    #[error("{0}")]
+    #[diagnostic(help("try removing it"))]
     Token(Token),
+    #[error("literal")]
     Literal,
+    #[error("type name")]
     TypeIdent,
+    #[error("indentifier")]
     TermIdent,
+    #[error("end of input")]
     End,
+    #[error("pattern")]
+    #[diagnostic(help("list spread in match can only have a discard or var"))]
+    Match,
 }
 
 impl From<char> for Pattern {
@@ -105,16 +115,3 @@ impl From<Token> for Pattern {
         Self::Token(tok)
     }
 }
-
-impl fmt::Display for Pattern {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Pattern::Token(token) => write!(f, "{}", token),
-            Pattern::Char(c) => write!(f, "{:?}", c),
-            Pattern::Literal => write!(f, "literal"),
-            Pattern::TypeIdent => write!(f, "type name"),
-            Pattern::TermIdent => write!(f, "identifier"),
-            Pattern::End => write!(f, "end of input"),
-        }
-    }
-}

crates/lang/src/parser/lexer.rs

@@ -31,6 +31,7 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
         just('|').to(Token::Vbar),
         just("&&").to(Token::AmperAmper),
         just("\n\n").to(Token::EmptyLine),
+        just('#').to(Token::Hash),
     ));
 
     let grouping = choice((
@@ -74,7 +75,7 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
         "pub" => Token::Pub,
         "use" => Token::Use,
         "todo" => Token::Todo,
-        "try" => Token::Try,
+        "trace" => Token::Trace,
         "type" => Token::Type,
         "when" => Token::When,
         _ => {

crates/lang/src/parser/token.rs

@@ -69,7 +69,7 @@ pub enum Token {
     Pub,
     Use,
     Todo,
-    Try,
+    Trace,
     Type,
     When,
 }
@@ -143,7 +143,7 @@ impl fmt::Display for Token {
             Token::Opaque => "opaque",
             Token::Pub => "pub",
             Token::Todo => "todo",
-            Token::Try => "try",
+            Token::Trace => "try",
             Token::Type => "type",
         };
         write!(f, "\"{}\"", s)