cgen: sum types: match

vlib/v/ast/ast.v

@@ -344,12 +344,13 @@ mut:
 
 pub struct MatchExpr {
 pub:
-	tok_kind  token.Kind
-	cond      Expr
-	branches  []MatchBranch
-	pos       token.Position
+	tok_kind    token.Kind
+	cond        Expr
+	branches    []MatchBranch
+	pos         token.Position
 mut:
-	expr_type table.Type // type of `x` in `match x {`
+	expr_type   table.Type // type of `x` in `match x {`
+	is_sum_type bool
 }
 
 pub struct MatchBranch {

vlib/v/gen/cgen.v

@@ -315,7 +315,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			}
 		}
 		ast.TypeDecl {
-			g.writeln('// type')
+			g.writeln('// TypeDecl')
 		}
 		ast.UnsafeStmt {
 			g.stmts(it.stmts)
@@ -728,7 +728,10 @@ fn (g mut Gen) expr(node ast.Expr) {
 					}
 					g.write('if (')
 					for i, expr in branch.exprs {
-						if type_sym.kind == .string {
+						if it.is_sum_type {
+							g.write('${tmp}.typ == ')
+						}
+						else if type_sym.kind == .string {
 							g.write('string_eq($tmp, ')
 						}
 						else {
@@ -909,7 +912,10 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write(it.field)
 		}
 		ast.Type {
-			g.write('/* Type */')
+			// match sum Type
+			// g.write('/* Type */')
+			g.write('_type_idx_')
+			g.write(g.typ(it.typ))
 		}
 		else {
 			// #printf("node=%d\n", node.typ);
@@ -1270,7 +1276,7 @@ fn (g mut Gen) write_sorted_types() {
 }
 
 fn (g mut Gen) write_types(types []table.TypeSymbol) {
-	for typ in types {
+	for i, typ in types {
 		if typ.name.starts_with('C.') {
 			continue
 		}
@@ -1288,11 +1294,12 @@ fn (g mut Gen) write_types(types []table.TypeSymbol) {
 				// g.definitions.writeln('} $name;\n')
 				//
 				g.definitions.writeln('};\n')
+				g.typedefs.writeln('#define _type_idx_$name $i')
 			}
 			table.Enum {
 				g.definitions.writeln('typedef enum {')
-				for i, val in it.vals {
-					g.definitions.writeln('\t${name}_$val, // $i')
+				for j, val in it.vals {
+					g.definitions.writeln('\t${name}_$val, // $j')
 				}
 				g.definitions.writeln('} $name;\n')
 			}

vlib/v/gen/tests/3.c

@@ -1,3 +1,15 @@
+struct IfExpr {
+};
+
+struct IntegerLiteral {
+};
+
+// Sum type
+typedef struct {
+	void* obj;
+	int typ;
+} Expr;
+
 struct User {
 	int age;
 	string name;
@@ -8,6 +20,9 @@ struct User {
 typedef Option Option_int;
 Option_int get_opt();
 void User_foo(User* u);
+void println(string s);
+void handle_expr(Expr e);
+// TypeDecl
 
 Option_int get_opt() {
 	return opt_ok(& (int []) { 0 }, sizeof(int));
@@ -20,6 +35,26 @@ tos3(""),
 }), u->age);
 }
 
+void println(string s) {
+}
+
+void handle_expr(Expr e) {
+	Expr tmp1 = e;
+	if (tmp1.typ == _type_idx_IfExpr) {
+	println(tos3("if"));
+
+	}
+	else if (tmp1.typ == _type_idx_IntegerLiteral) {
+	println(tos3("integer"));
+
+	}
+	else {
+	println(tos3("else"));
+
+	}
+	;
+}
+
 int main() {
 	User user = (User){
 0};

vlib/v/gen/tests/3.vv

@@ -1,3 +1,8 @@
+type Expr = IfExpr | IntegerLiteral
+
+struct IfExpr{}
+struct IntegerLiteral{}
+
 struct User {
 	age int
 	name string
@@ -12,6 +17,26 @@ fn (u &User) foo() {
 	zzz := [''].repeat(u.age)
 }
 
+fn println(s string) {}
+
+fn handle_expr(e Expr) {
+	match e {
+		IfExpr {
+			println('if')
+
+
+		}
+		IntegerLiteral {
+			println('integer')
+
+		}
+		else {
+			println('else')
+		}
+	}
+
+}
+
 fn main() {
 	user := User{}
 	user.age = 10

vlib/v/parser/parser.v

@@ -703,7 +703,7 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 		// Map `{"age": 20}` or `{ x | foo:bar, a:10 }`
 		.lcbr {
 			p.next()
-			if p.tok.kind == .string{
+			if p.tok.kind == .string {
 				mut keys := []ast.Expr
 				mut vals := []ast.Expr
 				for p.tok.kind != .rcbr && p.tok.kind != .eof {
@@ -1169,7 +1169,7 @@ fn (p mut Parser) string_expr() ast.Expr {
 		return node
 	}
 	// Handle $ interpolation
-	for p.tok.kind == .string{
+	for p.tok.kind == .string {
 		p.next()
 		if p.tok.kind != .str_dollar {
 			continue
@@ -1596,6 +1596,7 @@ fn (p mut Parser) global_decl() ast.GlobalDecl {
 fn (p mut Parser) match_expr() ast.MatchExpr {
 	p.check(.key_match)
 	is_mut := p.tok.kind == .key_mut
+	mut is_sum_type := false
 	if is_mut {
 		p.next()
 	}
@@ -1626,6 +1627,7 @@ fn (p mut Parser) match_expr() ast.MatchExpr {
 				p.next()
 				p.parse_type()
 			}
+			is_sum_type = true
 		}
 		else {
 			// Expression match
@@ -1653,6 +1655,7 @@ fn (p mut Parser) match_expr() ast.MatchExpr {
 	return ast.MatchExpr{
 		branches: branches
 		cond: cond
+		is_sum_type: is_sum_type
 	}
 }