feat: support source pointers and references

source/ast/ast.hon

@@ -1,9 +1,9 @@
 #! grammar:
-#! * type ..... -> identifier {'.' member} | '[' (expr | '_') ']' ['mut'] type | 'struct' '{' fields '}' | 'enum' ['(' type ')'] '{' members '}' | 'union' ['(' (type | 'enum') ')'] '{' fields '}' | ('distinct' | 'alias') type
+#! * type ..... -> identifier {'.' member} | ('@' | '*') ['mut'] type | '[' (expr | '_') ']' ['mut'] type | 'struct' '{' fields '}' | 'enum' ['(' type ')'] '{' members '}' | 'union' ['(' (type | 'enum') ')'] '{' fields '}' | ('distinct' | 'alias') type
 #! * binding ... -> :: | :=
 #! * literal .. -> int | float | string | 'true' | 'false'
 #! * op ....... -> '+' | '-' | '*' | '/' | '==' | '!=' | '<' | '<=' | '>' | '>=' | 'and' | 'or'
-#! * expr ..... -> identifier | literal | type | '.' member | '[' [expr {',' expr} [',']] ']' | [type] '{' [initializer {',' initializer} [',']] '}' | '(' expr ')' | ('-' | '!') expr | expr op expr | expr '(' [expr {',' expr} [',']] ')' | expr '[' expr ']' | expr '.' (member | int) | expr ('..' | '..=') expr | 'match' expr '{' match_arms '}'
+#! * expr ..... -> identifier | literal | type | '.' member | '[' [expr {',' expr} [',']] ']' | [type] '{' [initializer {',' initializer} [',']] '}' | '(' expr ')' | ('-' | '!' | '&') expr | expr '^' | expr op expr | expr '(' [expr {',' expr} [',']] ')' | expr '[' expr ']' | expr '.' (member | int) | expr ('..' | '..=') expr | 'match' expr '{' match_arms '}'
 #! * decl ..... -> identifier [type] binding expr | ['test'] [identifier '::'] 'import' string
 #! * block .... -> '{' {stmt} '}'
 #! * arm ...... -> block | stmt (single statements become canonical blocks)
@@ -11,7 +11,7 @@
 #! enum members and tagged-union variants accept keyword names; member names do not enter lexical scopes.
 #! * stmt ..... -> decl | expr | expr '=' expr | 'return' [expr] | 'break' | 'continue' | 'if' expr arm ['else' arm] | 'while' expr arm | 'for' expr '|' ['@'] identifier [',' identifier] '|' arm
 #! braceless guards/iterables require parentheses unless they are calls; else binds to the nearest if.
-#! precedence (tightest first): calls/indices/selections, unary -/!, multiplication/division, addition/subtraction, relational comparisons, equality, and, or, ranges. compound range endpoints require their own parentheses.
+#! precedence (tightest first): calls/indices/selections/dereference, unary -/!/& higher than multiplication/division, addition/subtraction, relational comparisons, equality, and, or, ranges. compound range endpoints require their own parentheses.
 #! binary operators associate left; unary operators associate right.
 
 import "@std/debug"
@@ -44,6 +44,7 @@ ExprKind :: enum {
     call
     range
     array_type
+    pointer_type
     array_literal
     record_type
     record_literal
@@ -82,7 +83,12 @@ Mutability :: enum {
     constant, variable
 }
 
-UnaryOperator :: enum { negate, logical_not }
+UnaryOperator :: enum {
+    negate
+    logical_not
+    address_of
+    dereference
+}
 
 BinaryOperator :: enum {
     add, subtract
@@ -105,6 +111,7 @@ NodeKind :: enum {
     expr_call
     expr_range
     expr_array_type
+    expr_pointer_type
     expr_array_literal
     expr_record_type
     expr_record_literal
@@ -231,6 +238,12 @@ ArrayTypeView :: struct {
     mutable bool
 }
 
+PointerTypeView :: struct {
+    element NodeId
+    mutable bool
+    many bool
+}
+
 RecordLiteralView :: struct {
     span Span
     type ?NodeId
@@ -482,6 +495,22 @@ add_array_type proc(
     }, span)
 }
 
+add_pointer_type proc(
+    builder @mut Builder,
+    span Span,
+    element NodeId,
+    mutable, many bool,
+) NodeId ! mem.AllocError {
+    mutable_flag :: if (mutable) u32(1) else u32(0)
+    many_flag :: if (many) u32(1) else u32(0)
+    return try add_node(builder, Node{
+        kind = .expr_pointer_type,
+        main = NodeData{ extra = mutable_flag },
+        data0 = NodeData{ extra = many_flag },
+        data1 = NodeData{ node_id = element },
+    }, span)
+}
+
 add_array_literal proc(builder @mut Builder, span Span, elements []NodeId) NodeId ! mem.AllocError {
     start :: builder.storage.extra.items.len
     for (elements) |element| _ = try add_extra(builder, u32(element))
@@ -1073,6 +1102,7 @@ expression_kind proc(kind NodeKind) ExprKind {
         .expr_call: .call
         .expr_range: .range
         .expr_array_type: .array_type
+        .expr_pointer_type: .pointer_type
         .expr_array_literal: .array_literal
         .expr_record_type: .record_type
         .expr_record_literal: .record_literal
@@ -1154,6 +1184,16 @@ array_type proc(tree @Tree, id NodeId) ArrayTypeView {
     }
 }
 
+pointer_type proc(tree @Tree, id NodeId) PointerTypeView {
+    node :: get_node(&tree.storage, id)
+    debug.assert(node.kind == .expr_pointer_type)
+    return PointerTypeView{
+        element = node.data1.node_id,
+        mutable = node.main.extra != 0,
+        many = node.data0.extra != 0,
+    }
+}
+
 array_element_count proc(tree @Tree, id NodeId) usize {
     node :: get_node(&tree.storage, id)
     debug.assert(node.kind == .expr_array_literal)