crates/codegen/src/ts.rs

@@ -31,10 +31,9 @@ impl Codegen {
         macro_rules! semicolon { () => { if should_gen_semicolon { ";" } else { "" } }; }
 
         match ir {
-            IRKind::Define { name, type_hint, value, mutable } => {
+            IRKind::Define { name, type_hint, value } => {
                 format!(
-                    "{} {}: {} = {}{}\n",
-                    if *mutable { "let" } else { "const" },
+                    "const {}: {} = {}{}\n",
                     name, 
                     type_hint,
                     self.gen_ir(value, false),

crates/hir/src/lib.rs

@@ -13,7 +13,7 @@ pub enum Value { Int(i64), Boolean(bool), String(String), Ident(String) }
 
 #[derive(Debug, Clone)]
 pub enum IRKind {
-    Define { name: String, type_hint: String, value: Box<Self>, mutable: bool },
+    Define { name: String, type_hint: String, value: Box<Self> },
     Fun { name: String, return_type_hint: String, args: Vec<(String, String)>, body: Box<Self> },
     Call { name: String, args: Vec<Self> },
     Intrinsic { name: String, args: Vec<Self> },
@@ -115,16 +115,14 @@ pub fn expr_to_ir(expr: &Expr) -> (Option<IRKind>, Option<LoweringError>) {
                         _ => return (None, Some(LoweringError { span: name.1.clone(), message: "Expected identifier".to_string(), note: None }))
                     };
 
-                    // Get all the `Hole` indexes
-                    let mut indexes = Vec::new();
-                    for (i, arg) in args.0.iter().enumerate() {
-                        if let Expr::Hole(..) = &arg.0 {
-                            indexes.push(i);
-                        }
-                    }
+                    // Get the index where the `Hole` is at
+                    let index = args.0.iter().position(|arg| match arg.0 {
+                        Expr::Hole(..) => true,
+                        _ => false
+                    });
 
                     // If there is no `Hole` in the args then return early
-                    if indexes.is_empty() {
+                    if let None = index {
                         return (None, Some(LoweringError {
                             span: rhs.1.clone(),
                             message: "Expected hole in piping".to_string(),
@@ -134,9 +132,7 @@ pub fn expr_to_ir(expr: &Expr) -> (Option<IRKind>, Option<LoweringError>) {
 
                     // Remove the `Hole` from the args
                     let mut new_args = args.0.clone();
-                    for index in indexes.iter().rev() {
-                        new_args.remove(*index);
-                    }
+                    new_args.remove(index.unwrap());
 
                     // Make a new call expression with the new args
                     let new_call = match call {
@@ -186,18 +182,12 @@ pub fn expr_to_ir(expr: &Expr) -> (Option<IRKind>, Option<LoweringError>) {
             };
         },
 
-        Expr::Let { name, type_hint, value, mutable } => {
+        Expr::Let { name, type_hint, value } => {
             let value = expr_to_ir(&value.0);
             if_err_return!(value.1);
 
             let value = value.0.unwrap();
-            let ir_kind = IRKind::Define {
-                name: name.clone(),
-                type_hint: gen_type_hint(type_hint),
-                value: Box::new(value),
-                mutable: *mutable
-            };
-
+            let ir_kind = IRKind::Define { name: name.clone(), type_hint: gen_type_hint(type_hint), value: Box::new(value) };
             return (Some(ir_kind), None);
         },
 

crates/lexer/src/lib.rs

@@ -3,7 +3,7 @@ use chumsky::prelude::*;
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum Token {
     // Keywords
-    KwLet, KwMut, KwFun,
+    KwLet, KwFun,
     KwDo, KwEnd,
     KwIf, KwThen, KwElse,
     KwReturn,
@@ -30,7 +30,6 @@ impl std::fmt::Display for Token {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             Token::KwLet => write!(f, "let"),
-            Token::KwMut => write!(f, "mut"),
             Token::KwFun => write!(f, "fun"),
             Token::KwDo => write!(f, "do"),
             Token::KwEnd => write!(f, "end"),

crates/parser/src/lib.rs

@@ -18,7 +18,6 @@ pub enum Expr {
         name: String,
         type_hint: String,
         value: Box<Spanned<Self>>,
-        mutable: bool,
     },
     Fun {
         name: String,
@@ -194,19 +193,17 @@ fn expr_parser() -> impl Parser<Token, Vec<Spanned<Expr>>, Error = Simple<Token>
             });
 
         let let_ = just(Token::KwLet)
-            .ignore_then(just(Token::KwMut)).or_not()
-            .then(identifier)
+            .ignore_then(identifier)
             .then_ignore(just(Token::Colon))
             .then(identifier)
             .then_ignore(just(Token::Assign))
             .then(expr.clone())
-            .map(|(((mutable, name), type_hint), value)| {
+            .map(|((name, type_hint), value)| {
                 (
                     Expr::Let {
                         name: name.0.clone(),
                         type_hint: type_hint.0,
                         value: Box::new(value.clone()),
-                        mutable: mutable.is_some(),
                     },
                     name.1.start..value.1.end,
                 )
@@ -251,13 +248,13 @@ fn expr_parser() -> impl Parser<Token, Vec<Spanned<Expr>>, Error = Simple<Token>
                 )
             });
 
-        let do_block = expr.clone()
-            .then_ignore(just(Token::SemiColon))
-            .repeated()
-            .delimited_by(
-                just(Token::KwDo),
-                just(Token::KwEnd),
+        let do_block = just(Token::KwDo)
+            .ignore_then(
+                expr.clone()
+                    .then_ignore(just(Token::SemiColon))
+                    .repeated()
             )
+            .then_ignore(just(Token::KwEnd))
             .map_with_span(|body, span| {
                 (
                     Expr::Do {

example/pipe2.hz

@@ -12,8 +12,4 @@ fun main: void = do
     |> qux(_)
     |> quux(1, _)
     |> @write(_);
-
-    210
-    |> bar(_, _)
-    |> @write(_);
 end;