v2: start impl multi assign

vlib/v/ast/ast.v

@@ -14,7 +14,7 @@ AssignExpr | PrefixExpr | MethodCallExpr | IndexExpr | RangeExpr | MatchExpr
 
 pub type Stmt = VarDecl | GlobalDecl | FnDecl | Return | Module | Import | ExprStmt | 	
 ForStmt | StructDecl | ForCStmt | ForInStmt | CompIf | ConstDecl | Attr | BranchStmt | 	
-HashStmt
+HashStmt | AssignStmt
 // | IncDecStmt k
 // Stand-alone expression in a statement list.
 pub struct ExprStmt {
@@ -195,7 +195,8 @@ pub:
 
 pub struct IdentVar {
 pub mut:
-	typ  table.TypeRef
+	typ    table.TypeRef
+	is_mut bool
 	//name string
 }
 
@@ -205,6 +206,7 @@ pub enum IdentKind {
 	blank_ident
 	variable
 	constant
+	func
 }
 
 // A single identifier
@@ -219,6 +221,18 @@ mut:
 	info     IdentInfo
 }
 
+pub fn(i &Ident) var_info() IdentVar {
+	match i.info {
+		IdentVar {
+			return it
+		}
+		else {
+			// return IdentVar{}
+			panic('Ident.var_info(): info is not IdentVar variant')
+		}
+	}
+}
+
 pub struct InfixExpr {
 pub:
 // op    BinaryOp
@@ -326,14 +340,14 @@ pub:
 	name string
 }
 
-/*
+
 pub struct AssignStmt {
 pub:
-	left  Expr
-	right Expr
+	left  []Ident
+	right []Expr
 	op    token.Kind
 }
-*/
+
 
 // e.g. `[unsafe_fn]`
 pub struct Attr {

vlib/v/checker/checker.v

@@ -46,7 +46,7 @@ fn (c mut Checker) resolve_types() {
 	// update any types with unresolved sub types
 	for idx, t in c.table.types {
 		if t.kind == .array {
-			mut info := t.info as table.Array
+			mut info := t.array_info()
 			if info.elem_type.typ.kind == .unresolved {
 				info.elem_type = c.resolved[info.elem_type.idx]
 				mut t1 := &c.table.types[idx]
@@ -55,7 +55,7 @@ fn (c mut Checker) resolve_types() {
 			}
 		}
 		else if t.kind == .map {
-			mut info := t.info as table.Map
+			mut info := t.map_info()
 			mut updated := false
 			if info.key_type.typ.kind == .unresolved {
 				info.key_type = c.resolved[info.key_type.idx]
@@ -71,6 +71,22 @@ fn (c mut Checker) resolve_types() {
 				t1.info = info
 			}
 		}
+		else if t.kind == .multi_return {
+			mut info := t.mr_info()
+			mut types := info.types
+			mut updated := false
+			for i, ut in types {
+				if ut.typ.kind == .unresolved {
+					types[i] = c.resolved[ut.idx]
+					updated = true
+				}
+			}
+			if updated {
+				mut t1 := &c.table.types[idx]
+				info.types = types
+				t1.info = info
+			}
+		}
 	}
 }
 
@@ -197,6 +213,8 @@ pub fn (c &Checker) return_stmt(return_stmt ast.Return) {
 	}
 }
 
+pub fn (c &Checker) assign_stmt(assign_stmt ast.AssignStmt) {}
+
 pub fn (c &Checker) array_init(array_init ast.ArrayInit) table.TypeRef {
 	mut elem_type := c.table.type_ref(table.void_type_idx)
 	for i, expr in array_init.exprs {
@@ -224,6 +242,9 @@ fn (c &Checker) stmt(node ast.Stmt) {
 		ast.Return {
 			c.return_stmt(it)
 		}
+		ast.AssignStmt {
+			c.assign_stmt(it)
+		}
 		ast.VarDecl {
 			typ := c.expr(it.expr)
 			// println('checker: var decl $typ.name  it.typ=$it.typ.name $it.pos.line_nr')

vlib/v/gen/cgen.v

@@ -106,6 +106,23 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			}
 			g.writeln(';')
 		}
+		ast.AssignStmt {
+			// ident0 := it.left[0]
+			// info0 := ident0.var_info()
+			// for i, ident in it.left {
+			// 	info := ident.var_info()
+			// 	if info0.typ.typ.kind == .multi_return {
+			// 		if i == 0 {
+			// 			g.write('$info.typ.typ.name $ident.name = ')
+			// 			g.expr(it.right[0])
+			// 		} else {
+			// 			arg_no := i-1
+			// 			g.write('$info.typ.typ.name $ident.name = $ident0.name->arg[$arg_no]')
+			// 		}
+			// 	}
+			// 	g.writeln(';')
+			// }
+		}
 		ast.VarDecl {
 			g.write('$it.typ.typ.name $it.name = ')
 			g.expr(it.expr)

vlib/v/gen/jsgen.v

@@ -55,6 +55,7 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 			}
 			g.writeln(';')
 		}
+		ast.AssignStmt {}
 		ast.VarDecl {
 			g.write('var /* $it.typ.typ.name */ $it.name = ')
 			g.expr(it.expr)

vlib/v/gen/tests/4.c

@@ -1,9 +1,11 @@
+multi_return_int_string mr_test();
 int testa();
 string testb(int a);
 int testc(int a);
 int testa();
 int testb();
 int testa();
+
 int main() {
     Bar b = (Bar){
         .a = 122,
@@ -29,7 +31,11 @@ int main() {
     array_string g = new_array_from_c_array(2, 2, sizeof(array_string), {
         testb(1), tos3("hello"),
     });
-	return 0;
+    return 0;
+}
+
+multi_return_int_string mr_test() {
+    return (multi_return_int_string){.arg0=1,.arg1=tos3("v")};
 }
 
 int testa() {

vlib/v/gen/tests/4.vv

@@ -30,8 +30,13 @@ fn main() {
 
 	mut f := [testa(),2,3,4]
 	mut g := [testb(1),'hello']
+
+	m1, m2 := mr_test()
 }
 
+fn mr_test() (int, string) {
+	return 1,'v'
+}
 
 fn testa() int {
 	return testc(1)

vlib/v/gen/x64/gen.v

@@ -326,6 +326,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			g.ret()
 		}
 		ast.Return {}
+		ast.AssignStmt {}
 		ast.VarDecl {}
 		ast.ForStmt {}
 		ast.StructDecl {}

vlib/v/parser/parser.v

@@ -242,9 +242,13 @@ pub fn (p mut Parser) stmt() ast.Stmt {
 		}
 		else {
 			// `x := ...`
-			if p.tok.kind == .name && p.peek_tok.kind in [.decl_assign, .comma] {
+			// if p.tok.kind == .name && p.peek_tok.kind in [.decl_assign, .comma] {
+			if p.tok.kind == .name && p.peek_tok.kind in [.decl_assign] {
 				return p.var_decl()
 			}
+			if p.tok.kind == .name && p.peek_tok.kind in [.comma] {
+				return p.assign_stmt()
+			}
 			expr,typ := p.expr(0)
 			return ast.ExprStmt{
 				expr: expr
@@ -370,6 +374,60 @@ pub fn (p &Parser) warn(s string) {
 	}
 }
 
+pub fn(p mut Parser) parse_ident(is_c bool) (ast.Ident, table.TypeRef) {
+	mut node := ast.Ident{}
+	mut typ := p.table.type_ref(table.void_type_idx)
+	// p.warn('name ')
+	// left := p.parse_ident()
+	name := p.check_name()
+	mut ident := ast.Ident{
+		name: name
+	}
+	mut known_var := false
+	if var := p.table.find_var(name) {
+		known_var = true
+		typ = var.typ
+	} 
+	// variable
+	if known_var || p.tok.kind in [.comma, .decl_assign, .assign] {
+		// println('#### IDENT: $var.name: $var.typ.typ.name - $var.typ.idx')
+		ident.kind = .variable
+		ident.info = ast.IdentVar{
+			typ: typ
+			// name: ident.name
+			// expr: p.expr(0)// var.expr
+		}
+		return ident, typ
+	}else{
+		if is_c {
+			typ = p.table.type_ref(table.int_type_idx)
+			ident.info = ast.IdentVar{
+				typ: typ
+				// name: ident.name
+			}
+			return ident,typ
+		}
+		// const
+		if c := p.table.find_const(name) {
+			typ = c.typ
+			ident.kind = .constant
+			ident.info = ast.IdentVar{
+				typ: typ
+				// name: ident.name
+			}
+			node = ident
+		}else{
+			// Function object (not a call), e.g. `onclick(my_click)`
+			p.table.find_fn(name) or {
+				p.error('parse_ident: unknown identifier `$name`')
+				exit(0)
+			}
+			// p.next()
+		}
+	}
+	return node, typ
+}
+
 pub fn (p mut Parser) name_expr() (ast.Expr,table.TypeRef) {
 	mut node := ast.Expr{}
 	mut typ := p.table.type_ref(table.void_type_idx)
@@ -425,54 +483,9 @@ pub fn (p mut Parser) name_expr() (ast.Expr,table.TypeRef) {
 		p.check(.rcbr)
 	}
 	else {
-		// p.warn('name ')
-		// left := p.parse_ident()
-		mut ident := ast.Ident{
-			name: p.tok.lit
-		}
-		// variable
-		if var := p.table.find_var(p.tok.lit) {
-			// println('#### IDENT: $var.name: $var.typ.typ.name - $var.typ.idx')
-			typ = var.typ
-			ident.kind = .variable
-			ident.info = ast.IdentVar{
-				typ: typ
-				// name: ident.name
-				// expr: p.expr(0)// var.expr
-			}
-			// ident.ti = ti
-			node = ident
-			p.next()
-		}else{
-			if is_c {
-				typ = p.table.type_ref(table.int_type_idx)
-				ident.info = ast.IdentVar{
-					typ: typ
-					// name: ident.name
-				}
-				node = ident
-				p.next()
-				return node,typ
-			}
-			// const
-			if c := p.table.find_const(p.tok.lit) {
-				typ = c.typ
-				ident.kind = .constant
-				ident.info = ast.IdentVar{
-					typ: typ
-					// name: ident.name
-				}
-				node = ident
-				p.next()
-			}else{
-				// Function object (not a call), e.g. `onclick(my_click)`
-				p.table.find_fn(p.tok.lit) or {
-					p.error('name expr unknown identifier `$p.tok.lit`')
-					exit(0)
-				}
-				p.next()
-			}
-		}
+		mut ident := ast.Ident{}
+		ident, typ = p.parse_ident(is_c)
+		node = ident
 	}
 	return node,typ
 }
@@ -1047,7 +1060,6 @@ fn (p mut Parser) return_stmt() ast.Return {
 			break
 		}
 	}
-	// TODO: consider non deferred
 	stmt := ast.Return{
 		expected_type: p.return_type
 		exprs: exprs
@@ -1056,6 +1068,26 @@ fn (p mut Parser) return_stmt() ast.Return {
 	return stmt
 }
 
+pub fn (p mut Parser) assign_stmt() ast.AssignStmt {
+	// TODO: multiple return & multiple assign
+	mut idents := []ast.Ident
+	for {
+		ident, _ := p.parse_ident(false)
+		idents << ident
+		if p.tok.kind == .comma {
+			p.check(.comma)
+		} else {
+			break
+		}
+	}
+	p.next() // :=, =
+	expr, _ := p.expr(0)
+	return ast.AssignStmt{
+		left: idents
+		right: [expr]
+	}
+}
+
 fn (p mut Parser) var_decl() ast.VarDecl {
 	is_mut := p.tok.kind == .key_mut // || p.prev_tok == .key_for
 	// is_static := p.tok.kind == .key_static
@@ -1076,8 +1108,6 @@ fn (p mut Parser) var_decl() ast.VarDecl {
 	p.table.register_var(table.Var{
 		name: name
 		is_mut: is_mut
-		// expr: expr
-		
 		typ: typ
 	})
 	p.warn('var decl name=$name typ=$typ.typ.name')
@@ -1170,7 +1200,7 @@ fn (p mut Parser) add_unresolved(key string, expr ast.Expr) table.TypeRef {
 		typ: &table.Type{
 			parent: 0
 			kind: .unresolved
-			name: 'unresolved $p.unresolved.len'
+			name: 'unresolved $idx'
 		}
 	}
 	return t

vlib/v/table/atypes.v

@@ -77,6 +77,54 @@ pub enum Kind {
 	unresolved
 }
 
+[inline]
+pub fn(t &Type) mr_info() MultiReturn {
+	match t.info {
+		MultiReturn {
+			return it
+		}
+		else {
+			panic('Type.mr_info(): no multi return info')
+		}
+	}
+}
+
+[inline]
+pub fn(t &Type) array_info() Array {
+	match t.info {
+		Array {
+			return it
+		}
+		else {
+			panic('Type.mr_info(): no array info')
+		}
+	}
+}
+
+[inline]
+pub fn(t &Type) array_fixed_info() ArrayFixed {
+	match t.info {
+		ArrayFixed {
+			return it
+		}
+		else {
+			panic('Type.mr_info(): no array fixed info')
+		}
+	}
+}
+
+[inline]
+pub fn(t &Type) map_info() Map {
+	match t.info {
+		Map {
+			return it
+		}
+		else {
+			panic('Type.mr_info(): no map info')
+		}
+	}
+}
+
 /*
 pub fn (t Type) str() string {
 	return t.name
@@ -395,6 +443,7 @@ pub mut:
 pub struct MultiReturn {
 pub:
 	name  string
+mut:
 	types []TypeRef
 }