some syntax changes

mainly added the explicit type for declarations

Signed-off-by: Jakub Doka <jakub.doka2@gmail.com>

lang/README.md

@@ -299,17 +299,17 @@ main := fn(): uint {
 main := fn(): uint {
 	a := &1
 
-	b := @as(?^uint, null)
+	b: ?^uint = null
 	if decide() b = a
 
 	if b == null return 9001
 
-	c := @as(?uint, *b)
+	c: ?uint = *b
 	if decide() c = null
 
 	if c != null return 42
 
-	d := @as(?u16, null)
+	d: ?u16 = null
 	if decide() d = 1
 
 	if d == null return 69
@@ -331,7 +331,7 @@ main := fn(): uint {
 
 	if bar != null return 420
 
-	g := @as(?^uint, null)
+	g: ?^uint = null
 	g = a
 
 	_rd := *g
@@ -452,8 +452,8 @@ main := fn(): uint {
 	hardcoded_pointer := @as(^u8, @bitcast(10))
 	ecall_that_returns_uint := @as(uint, @eca(1, foo.Type.(10, 20), 5, 6))
 	embedded_array := @as([15]u8, @embed("text.txt"))
-	two_fields := @len(foo.Type)
+	two_fields := @lenof(foo.Type)
-	string_length := @len("foo\0")
+	string_length := @lenof("foo\0")
 	the_struct_kind := @kindof(foo.Type)
 	return @inline(foo.foo)
 }
@@ -482,7 +482,7 @@ arbitrary text
 - `@eca(...<expr>)`: invoke `eca` instruction, where return type is inferred and `<expr>...` are arguments passed to the call in the standard call convention
 - `@embed(<string>)`: include relative file as an array of bytes
 - `@inline(<func>, ...<args>)`: equivalent to `<func>(...<args>)` but function is guaranteed to inline, compiler will otherwise never inline
-- `@len(<ty>)`: reports a length of the type of indexing purposes or length ot a string constant
+- `@lenof(<ty>)`: reports a length of the type of indexing purposes or length ot a string constant
 - `@kindof(<ty>)`: gives an u8 integer describing the kind of type as an index to array `[Builtin, Struct, Tuple, Enum, Union, Ptr, Slice, Opt, Func, Template, Global, Const, Module]`
 - `@Any()`: generic parameter based on inference, TBD: this will ake arguments in the future that restrict what is accepted
 - `@error(...<expr>)`: emit compiler error, if reachable, and use arguments to construct a message, can display strings and types
@@ -544,7 +544,7 @@ fib_iter := fn(n: uint): uint {
 #### arrays
 ```hb
 main := fn(): uint {
-	addr := @as(u16, 0x1FF)
+	addr: u16 = 0x1FF
 	msg := u8.[0, 0, @intcast(addr), @intcast(addr >> 8)]
 	_force_stack := &msg
 
@@ -579,10 +579,10 @@ foo := fn(a: uint, b: uint, c: uint): uint {
 
 #### idk
 ```hb
-_edge_case := @as(uint, idk)
+_edge_case: uint = idk
 
 main := fn(): uint {
-	big_array := @as([128]u8, idk)
+	big_array: [128]u8 = idk
 	i := 0
 	loop if i >= 128 break else {
 		big_array[i] = 69
@@ -637,11 +637,11 @@ Vec := fn($Elem: type): type return struct {
 				vec.cap *= 2
 			}
 
-			new_alloc := @as(?^Elem, @bitcast(malloc(vec.cap * @sizeof(Elem), @alignof(Elem))))
+			new_alloc: ?^Elem = @bitcast(malloc(vec.cap * @sizeof(Elem), @alignof(Elem)))
 			if new_alloc == null return null
 
 			src_cursor := vec.data
-			dst_cursor := @as(^Elem, new_alloc)
+			dst_cursor: ^Elem = new_alloc
 			end := vec.data + vec.len
 
 			loop if src_cursor == end break else {
@@ -711,7 +711,7 @@ main := fn(): uint {
 	nums := Nums.(1, 2, 3, 4)
 	i := 0
 	sum := 0
-	$loop if i == @len(Nums) break else {
+	$loop if i == @lenof(Nums) break else {
 		sum += nums[i]
 		i += 1
 	}
@@ -837,7 +837,7 @@ main := fn(): int {
 Color := struct {b: u8}
 main := fn(): void {
 	color := Color.(0)
-	n := @as(u8, 1)
+	n: u8 = 1
 	loop {
 		if color.b == 255 | color.b == 0 {
 			n = -n
@@ -913,12 +913,12 @@ $H := 3
 $W := 3
 
 main := fn(): int {
-	y := @as(int, 0)
+	y: int = 0
 	loop if y == H break else {
-		x := @as(int, 0)
+		x: int = 0
 		loop if x == W break else {
-			c_r := @as(f64, @itf(x))
+			c_r: f64 = @itf(x)
-			c_i := @as(f64, @itf(y))
+			c_i: f64 = @itf(y)
 			if c_i * c_r >= 10.0 return 0
 			x += 1
 		}

lang/src/fmt.rs

@@ -558,7 +558,9 @@ impl<'a> Formatter<'a> {
                         f.write_str(op.name())?;
                         f.write_str(" ")?;
                     } else {
+                        if op != TokenKind::Colon {
                             f.write_str(" ")?;
+                        }
                         f.write_str(op.name())?;
                         f.write_str(" ")?;
                     }

lang/src/parser.rs

@@ -287,6 +287,10 @@ impl<'a, 'b> Parser<'a, 'b> {
     }
 
     fn unit_expr(&mut self) -> Option<Expr<'a>> {
+        self.unit_expr_low(true)
+    }
+
+    fn unit_expr_low(&mut self, eat_tail: bool) -> Option<Expr<'a>> {
         use {Expr as E, TokenKind as T};
 
         if matches!(
@@ -498,7 +502,7 @@ impl<'a, 'b> Parser<'a, 'b> {
                         Some(adv)
                     }
                 },
-                item: self.ptr_unit_expr()?,
+                item: self.arena.alloc(self.unit_expr_low(false)?),
                 pos,
             },
             T::Band | T::Mul | T::Xor | T::Sub | T::Que | T::Not | T::Dot => E::UnOp {
@@ -551,9 +555,13 @@ impl<'a, 'b> Parser<'a, 'b> {
             tok => self.report(token.start, format_args!("unexpected token: {tok}"))?,
         };
 
+        if eat_tail {
             loop {
                 let token = self.token;
-            if matches!(token.kind, T::LParen | T::Ctor | T::Dot | T::Tupl | T::Arr | T::LBrack) {
+                if matches!(
+                    token.kind,
+                    T::LParen | T::Ctor | T::Dot | T::Tupl | T::Arr | T::LBrack | T::Colon
+                ) {
                     self.next();
                 }
 
@@ -574,6 +582,15 @@ impl<'a, 'b> Parser<'a, 'b> {
                             self.arena.alloc(index)
                         },
                     },
+                    T::Colon => E::BinOp {
+                        left: {
+                            self.declare_rec(&expr, false);
+                            self.arena.alloc(expr)
+                        },
+                        pos,
+                        op: T::Colon,
+                        right: self.ptr_expr()?,
+                    },
                     T::Dot => E::Field {
                         target: self.arena.alloc(expr),
                         pos: token.start,
@@ -585,6 +602,7 @@ impl<'a, 'b> Parser<'a, 'b> {
                     _ => break,
                 }
             }
+        }
 
         if matches!(token.kind, T::Loop | T::LBrace | T::Fn | T::Struct) {
             self.pop_scope(frame);
@@ -1456,7 +1474,7 @@ pub fn find_decl<'a>(
     id: DeclId,
 ) -> Option<(&'a Expr<'a>, Ident)> {
     exprs.iter().find_map(|expr| match expr {
-        Expr::BinOp { left, op: TokenKind::Decl, .. } => {
+        Expr::BinOp { left, op: TokenKind::Decl | TokenKind::Colon, .. } => {
             left.declares(id, file).map(|id| (expr, id))
         }
         _ => None,

lang/src/son.rs

@@ -1081,6 +1081,21 @@ impl<'a> Codegen<'a> {
                     self.error(pos, fa!("cant logically negate '{}'", self.ty_display(val.ty)))
                 }
             }
+            Expr::BinOp {
+                left,
+                op: TokenKind::Colon,
+                right: &Expr::BinOp { left: ty, op: TokenKind::Assign, right, pos },
+                ..
+            } => {
+                let ty = self.ty(ty);
+                let mut right = self.checked_expr(right, ty, "declaration")?;
+
+                if right.ty.loc(self.tys) == Loc::Stack {
+                    self.spill(pos, &mut right);
+                }
+                self.assign_pattern(left, right);
+                Some(Value::VOID)
+            }
             Expr::BinOp { left, op: TokenKind::Decl, right, pos } => {
                 let mut right = self.expr(right)?;
 
@@ -1342,14 +1357,21 @@ impl<'a> Codegen<'a> {
                 let align = self.tys.align_of(ty);
                 self.gen_inferred_const(ctx, ty::Id::DINT, align)
             }
-            Expr::Directive { name: "len", args: [ety], .. } => {
+            Expr::Directive { name: "lenof", args: [ety], .. } => {
                 let ty = self.expr(ety)?;
                 let len = match self.ci.nodes[ty.id].kind {
-                    Kind::CInt { value }
+                    Kind::CInt { value } => match self.tys.len_of(ty::Id::from(value as u64)) {
-                        if let Some(len) = self.tys.len_of(ty::Id::from(value as u64)) =>
+                        Some(len) => len,
-                    {
+                        None => {
-                        len
+                            return self.error(
+                                ety.pos(),
+                                fa!(
+                                    "'@len' only supports structs and arrays or strings. got {}",
+                                    self.ty_display(ty::Id::from(value as u64))
+                                ),
+                            )
                         }
+                    },
                     Kind::Global { global } => self.tys.ins.globals[global].data.len() as u32 - 1,
                     _ => {
                         return self
@@ -2839,7 +2861,10 @@ impl<'a> Codegen<'a> {
         let prev_parent = mem::replace(&mut self.ci.parent, c.parent);
         let f = &self.files[c.file];
         let value = match c.ast.get(f) {
-            Expr::BinOp { left, op: TokenKind::Decl, right, .. } => left
+            &Expr::BinOp { left, op: TokenKind::Decl, right, .. }
+            | &Expr::BinOp {
+                left, op: TokenKind::Colon, right: &Expr::BinOp { right, .. }, ..
+            } => left
                 .find_pattern_path(c.name, right, |expr, is_ct| {
                     debug_assert!(is_ct);
                     self.ptr_expr_ctx(expr, ctx)
@@ -3945,7 +3970,9 @@ impl<'a> Codegen<'a> {
             Expr::Directive { name: "TypeOf", args: [expr], .. } => self.infer_type(expr),
             Expr::Directive { name: "ChildOf", args: [aty], .. } => {
                 let ty = self.parse_ty(sc.anon(), aty);
-                let Some(ty) = self.tys.base_of(ty).or(self.tys.inner_of(ty)) else {
+                let Some(ty) =
+                    self.tys.base_of(ty).or(self.tys.inner_of(ty)).or(self.tys.elem_of(ty))
+                else {
                     return self.error_low(
                         sc.file,
                         aty.pos(),

lang/src/ty.rs

@@ -616,12 +616,11 @@ impl core::fmt::Display for Display<'_> {
             K::Slice(idx) => {
                 let array = self.tys.ins.slices[idx];
                 f.write_str("[")?;
-                self.rety(array.elem).fmt(f)?;
+                if let Some(len) = array.len() {
-                if array.len != ArrayLen::MAX {
+                    len.fmt(f)?;
-                    f.write_str("; ")?;
-                    array.len.fmt(f)?;
                 }
-                f.write_str("]")
+                f.write_str("]")?;
+                self.rety(array.elem).fmt(f)
             }
             K::Const(idx) => {
                 let cnst = &self.tys.ins.consts[idx];
@@ -1260,6 +1259,7 @@ impl Types {
     pub fn len_of(&self, ty: Id) -> Option<u32> {
         Some(match ty.expand() {
             Kind::Struct(s) => self.struct_field_range(s).len() as _,
+            Kind::Tuple(s) => self.ins.tuples[s].fields.len() as _,
             Kind::Slice(s) => self.ins.slices[s].len()? as _,
             _ => return None,
         })
@@ -1274,6 +1274,13 @@ impl Types {
     pub fn tuple_fields(&self, tuple: Tuple) -> &[Id] {
         &self.ins.args[self.ins.tuples[tuple].fields.range()]
     }
+
+    pub fn elem_of(&self, ty: Id) -> Option<Id> {
+        match ty.expand() {
+            Kind::Slice(s) => Some(self.ins.slices[s].elem),
+            _ => None,
+        }
+    }
 }
 
 pub struct OptLayout {