sum types: allow modification in `match`

vlib/builtin/array.v

@@ -447,6 +447,7 @@ pub fn (a []char) index(v char) int {
 	return -1
 }
 
+/*
 // []int.reduce executes a given reducer function on each element of the array,
 // resulting in a single output value.
 pub fn (a []int) reduce(iter fn(accum, curr int)int, accum_start int) int {
@@ -457,6 +458,7 @@ pub fn (a []int) reduce(iter fn(accum, curr int)int, accum_start int) int {
 	}
 	return _accum
 }
+*/
 
 // array_eq<T> checks if two arrays contain all the same elements in the same order.
 // []int == []int (also for: i64, f32, f64, byte, string)

vlib/compiler/if_match.v

@@ -139,7 +139,9 @@ fn (p mut Parser) match_statement(is_expr bool) string {
 				// println('got child $sum_child_type')
 				p.register_var(Var{
 					name: 'it'
-					typ: sum_child_type
+					typ: sum_child_type+'*'
+					is_mut: true
+					ptr: true
 				})
 			}
 			else {
@@ -189,7 +191,8 @@ fn (p mut Parser) match_statement(is_expr bool) string {
 			p.check(.lcbr)
 			p.genln('{ ')
 			if is_sum_type {
-				p.genln(' $sum_child_type it = *($sum_child_type*)$tmp_var .obj ;')
+				//p.genln(' $sum_child_type it = *($sum_child_type*)$tmp_var .obj ;')
+				p.genln(' $sum_child_type* it = ($sum_child_type*)${tmp_var}.obj ;')
 			}
 			p.statements()
 			all_cases_return = all_cases_return && p.returns
@@ -261,12 +264,12 @@ fn (p mut Parser) if_statement(is_expr bool, elif_depth int) string {
 			name: var_name
 			typ: typ
 			is_mut: false // TODO
-			
+
 			is_used: true // TODO
 			// is_alloc: p.is_alloc || typ.starts_with('array_')
 			// line_nr: p.tokens[ var_token_idx ].line_nr
 			// token_idx: var_token_idx
-			
+
 		})
 		p.statements()
 		p.close_scope()

vlib/v/checker/checker.v

@@ -197,7 +197,12 @@ fn (c &Checker) stmt(node ast.Stmt) {
 		}
 		ast.VarDecl {
 			typ := c.expr(it.expr)
-			// println('var decl $typ.name  it.typ=$it.typ.name $it.pos.line_nr')
+			// println('checker: var decl $typ.name  it.typ=$it.typ.name $it.pos.line_nr')
+			/*
+			if typ.kind != .void {
+				it.typ = typ
+			}
+			*/
 			// if it.typ.kind == .unresolved {
 			// it.ti = typ
 			// println('unresolved var')
@@ -284,22 +289,7 @@ pub fn (c &Checker) expr(node ast.Expr) table.Type {
 			return c.selector_expr(it)
 		}
 		ast.IndexExpr {
-			mut typ := c.expr(it.left)
+			return c.index_expr(it)
-			if typ.name.starts_with('array_') {
-				elm_typ := typ.name[6..]
-				// TODO `typ = ... or ...`
-				x := c.table.find_type(elm_typ) or {
-					c.error(elm_typ, it.pos)
-					exit(0)
-				}
-				typ = x
-			}
-			else {
-				typ = table.int_type
-			}
-			return typ
-			// c.expr(it.index)
-			//return it.typ
 		}
 		ast.IfExpr {
 			typ := c.expr(it.cond)
@@ -320,6 +310,25 @@ pub fn (c &Checker) expr(node ast.Expr) table.Type {
 	return table.void_type
 }
 
+pub fn (c &Checker) index_expr(node ast.IndexExpr) table.Type {
+	mut typ := c.expr(node.left)
+	if typ.name.starts_with('array_') {
+		elm_typ := typ.name[6..]
+		// TODO `typ = ... or ...`
+		x := c.table.find_type(elm_typ) or {
+			c.error(elm_typ, node.pos)
+			exit(0)
+		}
+		typ = x
+	}
+	else {
+		typ = table.int_type
+	}
+	return typ
+	// c.expr(it.index)
+	// return it.typ
+}
+
 pub fn (c &Checker) error(s string, pos token.Position) {
 	print_backtrace()
 	final_msg_line := '$c.file_name:$pos.line_nr: error: $s'

vlib/v/gen/tests/1.vv

@@ -11,6 +11,17 @@ struct User {
 	age int
 }
 
+/*
+struct One {
+	two Two
+}
+
+struct Two {
+
+}
+*/
+
+
 fn main() {
 	a := 10
 	//bb := 2 + 'hi'

vlib/v/parser/parser.v

@@ -904,6 +904,7 @@ fn (p mut Parser) struct_decl() ast.StructDecl {
 			
 			ti: ti
 		}
+		// println('struct field $ti.name $field_name')
 	}
 	p.check(.rcbr)
 	p.table.register_type(table.Type{