v2: scopes, or, in, hex

vlib/v/parser/fn.v

@@ -21,6 +21,10 @@ pub fn (p mut Parser) call_expr() (ast.CallExpr,table.Type) {
 		
 		pos: tok.position()
 	}
+	if p.tok.kind == .key_orelse {
+		p.next()
+		p.parse_block()
+	}
 	if f := p.table.find_fn(fn_name) {
 		return node,f.return_type
 	}
@@ -45,6 +49,7 @@ pub fn (p mut Parser) call_args() []ast.Expr {
 }
 
 fn (p mut Parser) fn_decl() ast.FnDecl {
+	p.table.clear_vars()
 	is_pub := p.tok.kind == .key_pub
 	if is_pub {
 		p.next()

vlib/v/parser/parser.v

@@ -32,6 +32,8 @@ mut:
 	// vars []string
 	table       &table.Table
 	return_type table.Type // current function's return type
+	// scope_level int
+	// var_idx     int
 	is_c        bool
 	//
 	// prefix_parse_fns []PrefixParseFn
@@ -118,6 +120,7 @@ pub fn (p mut Parser) read_first_token() {
 }
 
 pub fn (p mut Parser) parse_block() []ast.Stmt {
+	p.table.open_scope()
 	p.check(.lcbr)
 	mut stmts := []ast.Stmt
 	if p.tok.kind != .rcbr {
@@ -130,6 +133,7 @@ pub fn (p mut Parser) parse_block() []ast.Stmt {
 		}
 	}
 	p.check(.rcbr)
+	p.table.close_scope()
 	// println('nr exprs in block = $exprs.len')
 	return stmts
 }
@@ -405,7 +409,7 @@ pub fn (p mut Parser) name_expr() (ast.Expr,table.Type) {
 		}
 		// variable
 		if var := p.table.find_var(p.tok.lit) {
-			println('#### IDENT: $var.name: $var.typ.name - $var.typ.idx')
+			// println('#### IDENT: $var.name: $var.typ.name - $var.typ.idx')
 			typ = var.typ
 			ident.kind = .variable
 			ident.info = ast.IdentVar{
@@ -592,6 +596,10 @@ fn (p mut Parser) dot_expr(left ast.Expr, left_ti &table.Type) (ast.Expr,table.T
 	if p.tok.kind == .lpar {
 		p.next()
 		args := p.call_args()
+		if p.tok.kind == .key_orelse {
+			p.next()
+			p.parse_block()
+		}
 		mcall_expr := ast.MethodCallExpr{
 			expr: left
 			name: field_name
@@ -645,9 +653,12 @@ fn (p &Parser) is_addative() bool {
 
 fn (p mut Parser) for_statement() ast.Stmt {
 	p.check(.key_for)
+	p.table.open_scope()
+	// defer { p.table.close_scope() }
 	// Infinite loop
 	if p.tok.kind == .lcbr {
 		stmts := p.parse_block()
+		p.table.close_scope()
 		return ast.ForStmt{
 			stmts: stmts
 			pos: p.tok.position()
@@ -685,6 +696,7 @@ fn (p mut Parser) for_statement() ast.Stmt {
 			inc = p.stmt()
 		}
 		stmts := p.parse_block()
+		p.table.close_scope()
 		return ast.ForCStmt{
 			stmts: stmts
 			init: init
@@ -693,8 +705,16 @@ fn (p mut Parser) for_statement() ast.Stmt {
 		}
 	}
 	// `for i in vals`, `for i in start .. end`
-	else if p.peek_tok.kind == .key_in {
+	else if p.peek_tok.kind == .key_in || p.peek_tok.kind == .comma {
 		var_name := p.check_name()
+		if p.tok.kind == .comma {
+			p.check(.comma)
+			val_name := p.check_name()
+			p.table.register_var(table.Var{
+				name: val_name
+				typ: table.int_type
+			})
+		}
 		p.check(.key_in)
 		start := p.tok.lit.int()
 		p.expr(0)
@@ -708,6 +728,7 @@ fn (p mut Parser) for_statement() ast.Stmt {
 		})
 		stmts := p.parse_block()
 		// println('nr stmts=$stmts.len')
+		p.table.close_scope()
 		return ast.ForStmt{
 			stmts: stmts
 			pos: p.tok.position()
@@ -716,6 +737,7 @@ fn (p mut Parser) for_statement() ast.Stmt {
 	// `for cond {`
 	cond,_ := p.expr(0)
 	stmts := p.parse_block()
+	p.table.close_scope()
 	return ast.ForStmt{
 		cond: cond
 		stmts: stmts
@@ -735,7 +757,12 @@ fn (p mut Parser) if_expr() (ast.Expr,table.Type) {
 	mut else_stmts := []ast.Stmt
 	if p.tok.kind == .key_else {
 		p.check(.key_else)
-		else_stmts = p.parse_block()
+		if p.tok.kind == .key_if {
+			p.if_expr()
+		}
+		else {
+			else_stmts = p.parse_block()
+		}
 	}
 	mut ti := table.void_type
 	// mut left := ast.Expr{}
@@ -944,13 +971,18 @@ fn (p mut Parser) struct_decl() ast.StructDecl {
 		// println('struct field $ti.name $field_name')
 	}
 	p.check(.rcbr)
-	p.table.register_type(table.Type{
-		kind: .struct_
-		name: name
-		info: table.Struct{
-			fields: fields
+	if name != 'string' {
+		ret := p.table.register_type(table.Type{
+			kind: .struct_
+			name: name
+			info: table.Struct{
+				fields: fields
+			}
+		})
+		if ret == -1 {
+			p.error('cannot register type `$name`, another type with this name exists')
 		}
-	})
+	}
 	return ast.StructDecl{
 		name: name
 		is_pub: is_pub

vlib/v/table/table.v

@@ -8,15 +8,17 @@ module table
 pub struct Table {
 	// struct_fields map[string][]string
 pub mut:
-	types      []Type
+	types       []Type
 	// type_idxs Hashmap
-	type_idxs  map[string]int
-	local_vars []Var
+	type_idxs   map[string]int
+	local_vars  []Var
+	scope_level int
+	var_idx     int
 	// fns Hashmap
-	fns        map[string]Fn
-	consts     map[string]Var
-	tmp_cnt    int
-	imports    []string
+	fns         map[string]Fn
+	consts      map[string]Var
+	tmp_cnt     int
+	imports     []string
 }
 
 pub struct Fn {
@@ -28,12 +30,14 @@ pub:
 
 pub struct Var {
 pub:
-	name      string
-	is_mut    bool
-	is_const  bool
-	is_global bool
+	name        string
+	idx         int
+	is_mut      bool
+	is_const    bool
+	is_global   bool
+	scope_level int
 mut:
-	typ       Type
+	typ         Type
 }
 
 pub fn new_table() &Table {
@@ -52,32 +56,21 @@ pub fn (t &Table) find_var_idx(name string) int {
 }
 
 pub fn (t &Table) find_var(name string) ?Var {
-	/*
-	for i in 0 .. p.var_idx {
-		if p.local_vars[i].name == name {
-			return p.local_vars[i]
+	for i in 0 .. t.var_idx {
+		if t.local_vars[i].name == name {
+			return t.local_vars[i]
 		}
 	}
-	*/
-
+	/*
 	// println(t.names)
 	for var in t.local_vars {
 		if var.name == name {
 			return var
 		}
 	}
-	return none
-}
+	*/
 
-pub fn (t mut Table) clear_vars() {
-	// shared a := [1, 2, 3]
-	// p.var_idx = 0
-	if t.local_vars.len > 0 {
-		// if p.pref.autofree {
-		// p.local_vars.free()
-		// }
-		t.local_vars = []
-	}
+	return none
 }
 
 pub fn (t mut Table) register_const(v Var) {
@@ -99,27 +92,76 @@ pub fn (t mut Table) register_global(name string, typ Type) {
 
 pub fn (t mut Table) register_var(v Var) {
 	println('register_var: $v.name - $v.typ.name')
-	t.local_vars << v
-	/*
 	mut new_var := {
 		v |
-		idx:p.var_idx,
-		scope_level:p.cur_fn.scope_level
+		idx:t.var_idx,
+		scope_level:t.scope_level
 	}
+	// t.local_vars << v
+	/*
 	if v.line_nr == 0 {
 		new_var.token_idx = p.cur_tok_index()
 		new_var.line_nr = p.cur_tok().line_nr
 	}
+	*/
 	// Expand the array
-	if p.var_idx >= p.local_vars.len {
-		p.local_vars << new_var
+	if t.var_idx >= t.local_vars.len {
+		t.local_vars << new_var
 	}
 	else {
-		p.local_vars[p.var_idx] = new_var
+		t.local_vars[t.var_idx] = new_var
+	}
+	t.var_idx++
+}
+
+pub fn (t mut Table) open_scope() {
+	t.scope_level++
+}
+
+pub fn (t mut Table) close_scope() {
+	// println('close_scope level=$f.scope_level var_idx=$f.var_idx')
+	// Move back `var_idx` (pointer to the end of the array) till we reach
+	// the previous scope level.  This effectivly deletes (closes) current
+	// scope.
+	mut i := t.var_idx - 1
+	for ; i >= 0; i-- {
+		var := t.local_vars[i]
+		/*
+		if p.pref.autofree && (v.is_alloc || (v.is_arg && v.typ == 'string')) {
+			// && !p.pref.is_test {
+			p.free_var(v)
+		}
+		*/
+
+		// if p.fileis('mem.v') {
+		// println(v.name + ' $v.is_arg scope=$v.scope_level cur=$p.cur_fn.scope_level')}
+		if var.scope_level != t.scope_level {
+			// && !v.is_arg {
+			break
+		}
+	}
+	/*
+	if p.cur_fn.defer_text.last() != '' {
+		p.genln(p.cur_fn.defer_text.last())
+		// p.cur_fn.defer_text[f] = ''
 	}
-	p.var_idx++
 	*/
 
+	t.scope_level--
+	// p.cur_fn.defer_text = p.cur_fn.defer_text[..p.cur_fn.scope_level + 1]
+	t.var_idx = i + 1
+	// println('close_scope new var_idx=$f.var_idx\n')
+}
+
+pub fn (p mut Table) clear_vars() {
+	// shared a := [1, 2, 3]
+	p.var_idx = 0
+	if p.local_vars.len > 0 {
+		// ///if p.pref.autofree {
+		// p.local_vars.free()
+		// ///}
+		p.local_vars = []
+	}
 }
 
 pub fn (t &Table) find_fn(name string) ?Fn {
@@ -240,7 +282,7 @@ pub fn (t mut Table) register_type(typ Type) int {
 				if ex_type.kind == typ.kind {
 					return existing_idx
 				}
-				panic('cannot register type `$typ.name`, another type with this name exists')
+				return -1
 			}
 	}
 	}