change case syntax

SYNTAX.md

@@ -70,7 +70,7 @@ Hazure is also [expression-oriented](https://en.wikipedia.org/wiki/Expression-or
     ```sml
     case 1 + 1 of
         | 2 -> @write("Yes");
-        \ @write("How?");
+        | else @write("How?");
     end;
     ```
 10) Do notation. It allows you to have multiple expression because something like right hand side of the function declaration `fun a: int = ...` can only have 1 expression. Do allows you to bypass that.

crates/hir/src/lib.rs

@@ -70,7 +70,7 @@ impl std::fmt::Display for IRKind {
                 )
             },
             IRKind::Fun { ref public, ref name, ref return_type_hint, ref args, ref body } => {
-                write!(f, "(fun{} {} {} {} {})",
+                write!(f, "(fun{} {} :{} [{}] {})",
                     if *public { " export" } else { "" },
                     name,
                     return_type_hint,

crates/lexer/src/lib.rs

@@ -16,7 +16,7 @@ pub enum Token {
 
     // Operators
     Plus, Minus, Multiply, Divide, Modulus,
-    Pipe, EndPipe,
+    Pipe,
     Not, Equal, NotEqual, Less, Greater,
     Pipeline, Arrow,
 
@@ -62,7 +62,6 @@ impl std::fmt::Display for Token {
             Token::Greater => write!(f, ">"),
             Token::Pipeline => write!(f, "|>"),
             Token::Pipe => write!(f, "|"),
-            Token::EndPipe => write!(f, "\\"),
             Token::Arrow => write!(f, "->"),
 
             Token::Assign => write!(f, "="),
@@ -102,7 +101,6 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
 
         just("|>").to(Token::Pipeline),
         just("|").to(Token::Pipe),
-        just("\\").to(Token::EndPipe),
 
         just('<').to(Token::Less),
         just('>').to(Token::Greater),

crates/parser/src/lib.rs

@@ -317,7 +317,8 @@ fn expr_parser() -> impl Parser<Token, Vec<Spanned<Expr>>, Error = Simple<Token>
                     .repeated()
             )
             .then(
-                just(Token::EndPipe)
+                just(Token::Pipe)
+                    .ignore_then(just(Token::KwElse))
                     .ignore_then(expr.clone())
                     .then_ignore(just(Token::SemiColon))
             )

example/case.hz

@@ -7,6 +7,6 @@ fun main: void = do
         | 3 -> do
             @write("Three");
         end;
-        \ @write("idk");
+        | else @write("idk");
     end;
 end;

example/factorial.hz

@@ -1,7 +1,7 @@
 fun factorial (n: int): int = do
     case n of
         | 0 -> return 1;
-        \ return n * factorial(n - 1);
+        | else return n * factorial(n - 1);
     end;
 end;