v/vlib/v/parser/parser.v

// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module parser

import (
	v.scanner
	v.ast
	v.token
	v.table
	v.pref
	term
	os
	filepath
)

const (
	colored_output = term.can_show_color_on_stderr()
)
/*
type PrefixParseFn fn()ast.Expr

type InfixParseFn fn(e ast.Expr)ast.Expr

type PostfixParseFn fn()ast.Expr
*/


struct Parser {
	scanner       &scanner.Scanner
	file_name     string
mut:
	tok           token.Token
	peek_tok      token.Token
	// vars []string
	table         &table.Table
	return_type   table.Type // current function's return type
	is_c          bool
	//
	// prefix_parse_fns []PrefixParseFn
	inside_if     bool
	pref          &pref.Preferences // Preferences shared from V struct
	builtin_mod   bool
	mod           string
	expr_mod      string
	expected_type table.Type
	scope         &ast.Scope
	imports       map[string]string
}

// for tests
pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
	s := scanner.new_scanner(text)
	mut p := Parser{
		scanner: s
		table: table
		pref: &pref.Preferences{}
		scope: scope
		// scope: &ast.Scope{start_pos: 0, parent: 0}
		
	}
	p.init_parse_fns()
	p.read_first_token()
	return p.stmt()
}

pub fn parse_file(path string, table &table.Table) ast.File {
	// println('parse_file("$path")')
	text := os.read_file(path) or {
		panic(err)
	}
	mut stmts := []ast.Stmt
	mut p := Parser{
		scanner: scanner.new_scanner(text)
		table: table
		file_name: path
		pref: &pref.Preferences{}
		scope: &ast.Scope{
			start_pos: 0
			parent: 0
		}
	}
	p.read_first_token()
	// p.scope = &ast.Scope{start_pos: p.tok.position(), parent: 0}
	// module decl
	module_decl := if p.tok.kind == .key_module { p.module_decl() } else { ast.Module{name: 'main'
	} }
	p.mod = module_decl.name
	p.builtin_mod = p.mod == 'builtin'
	// imports
	mut imports := []ast.Import
	for p.tok.kind == .key_import {
		imports << p.import_stmt()
	}
	// TODO: import only mode
	for {
		// res := s.scan()
		if p.tok.kind == .eof {
			// println('EOF, breaking')
			break
		}
		// println('stmt at ' + p.tok.str())
		stmts << p.top_stmt()
	}
	// println('nr stmts = $stmts.len')
	// println(stmts[0])
	p.scope.end_pos = p.tok.pos
	return ast.File{
		path: path
		mod: module_decl
		imports: imports
		stmts: stmts
		scope: p.scope
	}
}

pub fn parse_files(paths []string, table &table.Table) []ast.File {
	mut files := []ast.File
	for path in paths {
		files << parse_file(path, table)
	}
	return files
}

pub fn (p &Parser) init_parse_fns() {
	// p.prefix_parse_fns = make(100, 100, sizeof(PrefixParseFn))
	// p.prefix_parse_fns[token.Kind.name] = parse_name
	println('')
}

pub fn (p mut Parser) read_first_token() {
	// need to call next() twice to get peek token and current token
	p.next()
	p.next()
}

pub fn (p mut Parser) open_scope() {
	p.scope = &ast.Scope{
		parent: p.scope
		start_pos: p.tok.pos
	}
}

pub fn (p mut Parser) close_scope() {
	p.scope.end_pos = p.tok.pos
	p.scope.parent.children << p.scope
	p.scope = p.scope.parent
}

pub fn (p mut Parser) parse_block() []ast.Stmt {
	p.open_scope()
	p.check(.lcbr)
	mut stmts := []ast.Stmt
	if p.tok.kind != .rcbr {
		for {
			stmts << p.stmt()
			// p.warn('after stmt(): tok=$p.tok.str()')
			if p.tok.kind in [.eof, .rcbr] {
				break
			}
		}
	}
	p.check(.rcbr)
	// println('parse block')
	p.close_scope()
	// println('nr exprs in block = $exprs.len')
	return stmts
}

fn (p mut Parser) next() {
	p.tok = p.peek_tok
	p.peek_tok = p.scanner.scan()
	// println(p.tok.str())
}

fn (p mut Parser) check(expected token.Kind) {
	if p.tok.kind != expected {
		s := 'syntax error: unexpected `${p.tok.kind.str()}`, expecting `${expected.str()}`'
		p.error(s)
	}
	p.next()
}

fn (p mut Parser) check_name() string {
	name := p.tok.lit
	p.check(.name)
	return name
}

pub fn (p mut Parser) top_stmt() ast.Stmt {
	match p.tok.kind {
		.key_pub {
			match p.peek_tok.kind {
				.key_const {
					return p.const_decl()
				}
				.key_fn {
					return p.fn_decl()
				}
				.key_struct, .key_union, .key_interface {
					return p.struct_decl()
				}
				.key_enum {
					return p.enum_decl()
				}
				.key_type {
					return p.type_decl()
				}
				else {
					p.error('wrong pub keyword usage')
					return ast.Stmt{}
				}
	}
		}
		.lsbr {
			return p.attr()
		}
		.key_global {
			return p.global_decl()
		}
		.key_const {
			return p.const_decl()
		}
		.key_fn {
			return p.fn_decl()
		}
		.key_struct {
			return p.struct_decl()
		}
		.dollar {
			return p.comp_if()
		}
		.hash {
			return p.hash()
		}
		.key_type {
			return p.type_decl()
		}
		.key_enum {
			return p.enum_decl()
		}
		.key_union {
			return p.struct_decl()
		}
		.line_comment {
			// p.next()
			return ast.LineComment{
				text: p.scanner.line_comment
			}
		}
		.mline_comment {
			// p.next()
			return ast.MultiLineComment{
				text: p.scanner.line_comment
			}
		}
		else {
			// #printf("");
			p.error('parser: bad top level statement ' + p.tok.str())
			return ast.Stmt{}
		}
	}
}

pub fn (p mut Parser) stmt() ast.Stmt {
	match p.tok.kind {
		.key_assert {
			p.next()
			expr,_ := p.expr(0)
			return ast.AssertStmt{
				expr: expr
			}
		}
		.key_mut {
			return p.var_decl_and_assign_stmt()
		}
		.key_for {
			return p.for_statement()
		}
		.key_return {
			return p.return_stmt()
		}
		.dollar {
			return p.comp_if()
		}
		.key_continue, .key_break {
			tok := p.tok
			p.next()
			return ast.BranchStmt{
				tok: tok
			}
		}
		.key_unsafe {
			p.next()
			stmts := p.parse_block()
			return ast.UnsafeStmt{
				stmts: stmts
			}
		}
		.key_defer {
			p.next()
			stmts := p.parse_block()
			return ast.DeferStmt{
				stmts: stmts
			}
		}
		.key_goto {
			p.next()
			name := p.check_name()
			return ast.GotoStmt{
				name: name
			}
		}
		else {
			// `x := ...`
			if p.tok.kind == .name && p.peek_tok.kind in [.decl_assign, .comma] {
				return p.var_decl_and_assign_stmt()
			}
			// `label:`
			else if p.tok.kind == .name && p.peek_tok.kind == .colon {
				name := p.check_name()
				p.check(.colon)
				return ast.GotoLabel{
					name: name
				}
			}
			// expr,typ := p.expr(0)
			expr,_ := p.expr(0)
			return ast.ExprStmt{
				expr: expr
				// typ: typ
				
			}
		}
	}
}

// TODO: merge wtih AssignStmt & VarDecl
pub fn (p mut Parser) assign_expr(left ast.Expr) ast.AssignExpr {
	op := p.tok.kind
	p.next()
	val,_ := p.expr(0)
	node := ast.AssignExpr{
		left: left
		val: val
		op: op
		pos: p.tok.position()
	}
	return node
}

fn (p mut Parser) attr() ast.Attr {
	p.check(.lsbr)
	if p.tok.kind == .key_if {
		p.next()
	}
	name := p.check_name()
	p.check(.rsbr)
	return ast.Attr{
		name: name
	}
}

/*

fn (p mut Parser) range_expr(low ast.Expr) ast.Expr {
	// ,table.Type) {
	if p.tok.kind != .dotdot {
		p.next()
	}
	p.check(.dotdot)
	mut high := ast.Expr{}
	if p.tok.kind != .rsbr {
		high,_ = p.expr(0)
		// if typ.typ.kind != .int {
		// p.error('non-integer index `$typ.typ.name`')
		// }
	}
	node := ast.RangeExpr{
		low: low
		high: high
	}
	return node
}
*/

/*
pub fn (p mut Parser) assign_stmt() ast.AssignStmt {
	name := p.tok.lit
	// println('looking for $name')
	var := p.table.find_var(name) or {
		p.error('assign unknown variable `$name`')
		exit(1)
	}
	if !var.is_mut {
		p.error('`$var.name` is immutable, declare it with `mut $var.name := ...`')
	}
	left_expr,left_type := p.expr(0)
	op := p.tok.kind
	// println('assignn_stmt() ' + op.str())
	p.next()
	right_expr,right_type := p.expr(0)
	if !p.table.check(left_type, right_type) {
		p.error('oops')
	}
	return ast.AssignStmt{
		left: left_expr
		right: right_expr
		op: op
	}
}
*/


pub fn (p &Parser) error(s string) {
	print_backtrace()
	mut path := p.file_name
	// Get relative path
	workdir := os.getwd() + filepath.separator
	if path.starts_with(workdir) {
		path = path.replace(workdir, '')
	}
	final_msg_line := '$path:$p.tok.line_nr: error: $s'
	if colored_output {
		eprintln(term.bold(term.red(final_msg_line)))
	}
	else {
		eprintln(final_msg_line)
	}
	exit(1)
}

pub fn (p &Parser) error_at_line(s string, line_nr int) {
	final_msg_line := '$p.file_name:$line_nr: error: $s'
	if colored_output {
		eprintln(term.bold(term.red(final_msg_line)))
	}
	else {
		eprintln(final_msg_line)
	}
	exit(1)
}

pub fn (p &Parser) warn(s string) {
	final_msg_line := '$p.file_name:$p.tok.line_nr: warning: $s'
	if colored_output {
		eprintln(term.bold(term.blue(final_msg_line)))
	}
	else {
		eprintln(final_msg_line)
	}
}

pub fn (p mut Parser) parse_ident(is_c bool) ast.Ident {
	// p.warn('name ')
	mut name := p.check_name()
	if name == '_' {
		return ast.Ident{
			name: '_'
			kind: .blank_ident
			pos: p.tok.position()
		}
	}
	if p.expr_mod.len > 0 {
		name = '${p.expr_mod}.$name'
	}
	mut ident := ast.Ident{
		kind: .unresolved
		name: name
		is_c: is_c
		pos: p.tok.position()
	}
	// variable
	if p.expr_mod.len == 0 {
		if var := p.scope.find_var(name) {
			ident.kind = .variable
			ident.info = ast.IdentVar{}
		}
	}
	// handle consts/fns in checker
	return ident
}

fn (p mut Parser) struct_init() ast.StructInit {
	typ := p.parse_type()
	sym := p.table.get_type_symbol(typ)
	// p.warn('struct init typ=$sym.name')
	p.check(.lcbr)
	mut field_names := []string
	mut exprs := []ast.Expr
	mut i := 0
	// TODO `if sym.info is table.Struct`
	mut is_struct := false
	match sym.info {
		table.Struct {
			is_struct = true
		}
		else {}
	}
	is_short_syntax := !(p.peek_tok.kind == .colon || p.tok.kind == .rcbr) // `Vec{a,b,c}`
	// p.warn(is_short_syntax.str())
	for p.tok.kind != .rcbr {
		mut field_name := ''
		if is_short_syntax {
			expr,_ := p.expr(0)
			exprs << expr
		}
		else {
			field_name = p.check_name()
			field_names << field_name
		}
		// Set expected type for this field's expression
		// p.warn('$sym.name field $field_name')
		if is_struct {
			info := sym.info as table.Struct
			if is_short_syntax {}
			else {
				field := sym.find_field(field_name) or {
					p.error('field `${sym.name}.$field_name` not found')
					continue
				}
				p.expected_type = field.typ
			}
			// p.warn('setting exp $field.typ')
		}
		if !is_short_syntax {
			p.check(.colon)
			expr,_ := p.expr(0)
			exprs << expr
		}
		i++
		if p.tok.kind == .comma {
			p.check(.comma)
		}
	}
	node := ast.StructInit{
		typ: typ
		exprs: exprs
		fields: field_names
		pos: p.tok.position()
	}
	p.check(.rcbr)
	return node
}

pub fn (p mut Parser) name_expr() ast.Expr {
	mut node := ast.Expr{}
	is_c := p.tok.lit == 'C'
	mut mod := ''
	// p.warn('resetting')
	p.expr_mod = ''
	// `map[string]int` initialization
	if p.tok.lit == 'map' && p.peek_tok.kind == .lsbr {
		map_type := p.parse_map_type()
		return node
	}
	if p.peek_tok.kind == .dot && (is_c || p.known_import(p.tok.lit) || p.mod.all_after('.') == p.tok.lit) {
		if !is_c {
			// prepend the full import
			mod = p.imports[p.tok.lit]
		}
		p.next()
		p.check(.dot)
		p.expr_mod = mod
	}
	// p.warn('name expr  $p.tok.lit $p.peek_tok.str()')
	// fn call or type cast
	if p.peek_tok.kind == .lpar {
		name := p.tok.lit
		// type cast. TODO: finish
		// if name in table.builtin_type_names {
		if name in p.table.type_idxs && !(name in ['stat', 'sigaction']) {
			// TODO handle C.stat()
			to_typ := p.parse_type()
			p.check(.lpar)
			mut expr := ast.Expr{}
			expr,_ = p.expr(0)
			// TODO, string(b, len)
			if p.tok.kind == .comma && table.type_idx(to_typ) == table.string_type_idx {
				p.check(.comma)
				p.expr(0) // len
			}
			p.check(.rpar)
			node = ast.CastExpr{
				typ: to_typ
				expr: expr
			}
			p.expr_mod = ''
			return node
		}
		// fn call
		else {
			// println('calling $p.tok.lit')
			x := p.call_expr(is_c, mod) // TODO `node,typ :=` should work
			node = x
		}
	}
	else if p.peek_tok.kind == .lcbr && (p.tok.lit[0].is_capital() || is_c ||
	//
	p.tok.lit in table.builtin_type_names) &&
	//
	(p.tok.lit.len == 1 || !p.tok.lit[p.tok.lit.len - 1].is_capital())
	//
	{
		// || p.table.known_type(p.tok.lit)) {
		return p.struct_init()
	}
	else if p.peek_tok.kind == .dot && p.tok.lit[0].is_capital() {
		// `Color.green`
		mut enum_name := p.check_name()
		if mod != '' {
			enum_name = mod + '.' + enum_name
		}
		else {
			enum_name = p.prepend_mod(enum_name)
		}
		// p.warn('Color.green $enum_name ' + p.prepend_mod(enum_name) + 'mod=$mod')
		p.check(.dot)
		val := p.check_name()
		// println('enum val $enum_name . $val')
		p.expr_mod = ''
		return ast.EnumVal{
			enum_name: enum_name // lp.prepend_mod(enum_name)
			
			val: val
			pos: p.tok.position()
		}
	}
	else {
		mut ident := ast.Ident{}
		ident = p.parse_ident(is_c)
		node = ident
	}
	p.expr_mod = ''
	return node
}

pub fn (p mut Parser) expr(precedence int) (ast.Expr,table.Type) {
	// println('\n\nparser.expr()')
	mut typ := table.void_type
	mut node := ast.Expr{}
	// Prefix
	match p.tok.kind {
		.name {
			node = p.name_expr()
		}
		.str {
			node,typ = p.string_expr()
		}
		.dot {
			// .enum_val
			// node,typ = p.enum_val()
			node = p.enum_val()
		}
		.chartoken {
			typ = table.byte_type
			node = ast.CharLiteral{
				val: p.tok.lit
			}
			p.next()
		}
		// -1, -a, !x, &x, ~x
		.minus, .amp, .mul, .not, .bit_not {
			node = p.prefix_expr()
		}
		// .amp {
		// p.next()
		// }
		.key_true, .key_false {
			node = ast.BoolLiteral{
				val: p.tok.kind == .key_true
			}
			typ = table.bool_type
			p.next()
		}
		.key_match {
			// node,typ = p.match_expr()
			node = p.match_expr()
		}
		.number {
			node,typ = p.parse_number_literal()
		}
		.lpar {
			p.check(.lpar)
			node,typ = p.expr(0)
			p.check(.rpar)
			node = ast.ParExpr{
				expr: node
			}
		}
		.key_if {
			node = p.if_expr()
		}
		.lsbr {
			node = p.array_init()
		}
		.key_none {
			p.next()
			typ = table.none_type
			node = ast.None{}
		}
		.key_sizeof {
			p.next() // sizeof
			p.check(.lpar)
			if p.tok.lit == 'C' {
				p.next()
				p.check(.dot)
			}
			if p.tok.kind == .amp {
				p.next()
			}
			type_name := p.check_name()
			p.check(.rpar)
			node = ast.SizeOf{
				type_name: type_name
			}
			typ = table.int_type
		}
		// Map `{"age": 20}` or `{ x | foo:bar, a:10 }`
		.lcbr {
			p.next()
			if p.tok.kind == .str {
				mut keys := []ast.Expr
				mut vals := []ast.Expr
				for p.tok.kind != .rcbr && p.tok.kind != .eof {
					// p.check(.str)
					key,_ := p.expr(0)
					keys << key
					p.check(.colon)
					val,_ := p.expr(0)
					vals << val
					if p.tok.kind == .comma {
						p.next()
					}
				}
				node = ast.MapInit{
					keys: keys
					vals: vals
					pos: p.tok.position()
				}
			}
			else {
				name := p.check_name()
				mut fields := []string
				mut vals := []ast.Expr
				p.check(.pipe)
				for {
					fields << p.check_name()
					p.check(.colon)
					expr,_ := p.expr(0)
					vals << expr
					if p.tok.kind == .comma {
						p.check(.comma)
					}
					if p.tok.kind == .rcbr {
						break
					}
				}
				node = ast.Assoc{
					name: name
					fields: fields
					exprs: vals
				}
			}
			p.check(.rcbr)
		}
		else {
			p.error('parser: expr(): bad token `$p.tok.str()`')
		}
	}
	// Infix
	for precedence < p.tok.precedence() {
		if p.tok.kind.is_assign() {
			node = p.assign_expr(node)
		}
		else if p.tok.kind == .dot {
			node = p.dot_expr(node, typ)
		}
		else if p.tok.kind == .lsbr {
			node = p.index_expr(node)
		}
		else if p.tok.kind == .key_as {
			p.next()
			typ = p.parse_type()
		}
		else if p.tok.kind.is_infix() {
			node,typ = p.infix_expr(node)
		}
		// Postfix
		else if p.tok.kind in [.inc, .dec] {
			node = ast.PostfixExpr{
				op: p.tok.kind
				expr: node
				pos: p.tok.position()
			}
			p.next()
			return node,typ
		}
		else {
			return node,typ
		}
	}
	return node,typ
}

fn (p mut Parser) prefix_expr() ast.PrefixExpr {
	op := p.tok.kind
	p.next()
	right,_ := p.expr(1)
	return ast.PrefixExpr{
		op: op
		right: right
	}
}

fn (p mut Parser) index_expr(left ast.Expr) ast.IndexExpr {
	// left == `a` in `a[0]`
	p.next() // [
	if p.tok.kind == .dotdot {
		// [..end]
		p.next()
		high,_ := p.expr(0)
		p.check(.rsbr)
		return ast.IndexExpr{
			left: left
			pos: p.tok.position()
			index: ast.RangeExpr{
				low: ast.Expr{}
				high: high
			}
		}
	}
	expr,_ := p.expr(0) // `[expr]` or  `[expr..]`
	if p.tok.kind == .dotdot {
		// [start..end] or [start..]
		p.check(.dotdot)
		mut high := ast.Expr{}
		if p.tok.kind != .rsbr {
			high,_ = p.expr(0)
		}
		p.check(.rsbr)
		return ast.IndexExpr{
			left: left
			pos: p.tok.position()
			index: ast.RangeExpr{
				low: expr
				high: high
			}
		}
	}
	// get the element type
	/*
	mut typ := left_type
	left_type_sym := p.table.get_type_symbol(left_type)
	if left_type_sym.kind == .array {
		info := left_type_sym.info as table.Array
		typ = info.elem_type
	}
	*/
	// [expr]
	p.check(.rsbr)
	return ast.IndexExpr{
		left: left
		index: expr
		pos: p.tok.position()
	}
}

fn (p mut Parser) filter(typ table.Type) {
	p.scope.register_var(ast.VarDecl{
		name: 'it'
		typ: typ
	})
}

fn (p mut Parser) dot_expr(left ast.Expr, left_type table.Type) ast.Expr {
	p.next()
	field_name := p.check_name()
	if field_name == 'filter' {
		p.open_scope()
		p.filter(left_type)
		defer {
			p.close_scope()
		}
	}
	// Method call
	if p.tok.kind == .lpar {
		p.next()
		args,muts := p.call_args()
		mut or_stmts := []ast.Stmt
		if p.tok.kind == .key_orelse {
			p.next()
			or_stmts = p.parse_block()
		}
		mcall_expr := ast.MethodCallExpr{
			expr: left
			name: field_name
			args: args
			muts: muts
			pos: p.tok.position()
			or_block: ast.OrExpr{
				stmts: or_stmts
			}
		}
		mut node := ast.Expr{}
		node = mcall_expr
		return node
	}
	sel_expr := ast.SelectorExpr{
		expr: left
		field: field_name
		pos: p.tok.position()
	}
	mut node := ast.Expr{}
	node = sel_expr
	return node
}

fn (p mut Parser) infix_expr(left ast.Expr) (ast.Expr,table.Type) {
	op := p.tok.kind
	// mut typ := p.
	// println('infix op=$op.str()')
	precedence := p.tok.precedence()
	pos := p.tok.position()
	p.next()
	mut typ := table.Type{}
	mut right := ast.Expr{}
	right,typ = p.expr(precedence)
	if op.is_relational() {
		typ = table.bool_type
	}
	mut expr := ast.Expr{}
	expr = ast.InfixExpr{
		left: left
		right: right
		right_type: typ
		op: op
		pos: pos
	}
	return expr,typ
}

// Implementation of Pratt Precedence
/*
[inline]
fn (p &Parser) is_addative() bool {
	return p.tok.kind in [.plus, .minus] && p.peek_tok.kind in [.number, .name]
}
*/
// `.green`
// `pref.BuildMode.default_mode`
fn (p mut Parser) enum_val() ast.EnumVal {
	p.check(.dot)
	val := p.check_name()
	/*
	if p.expected_type == 0 {
		p.error('wtf')
	}
	*/

	/*
	sym := p.table.get_type_symbol(p.expected_type) //or {
		//return ast.EnumVal{val:val}
	//}
	p.warn(sym.name)
	*/

	return ast.EnumVal{
		val: val
		pos: p.tok.position()
	}
}

fn (p mut Parser) for_statement() ast.Stmt {
	p.check(.key_for)
	p.open_scope()
	// defer { p.close_scope() }
	// Infinite loop
	if p.tok.kind == .lcbr {
		pos := p.tok.position()
		stmts := p.parse_block()
		p.close_scope()
		return ast.ForStmt{
			stmts: stmts
			pos: pos
			is_inf: true
		}
	}
	else if p.tok.kind == .key_mut {
		p.error('`mut` is not required in for loops')
	}
	// for i := 0; i < 10; i++ {
	else if p.peek_tok.kind in [.decl_assign, .assign, .semicolon] || p.tok.kind == .semicolon {
		mut init := ast.Stmt{}
		mut cond := ast.Expr{}
		mut inc := ast.Stmt{}
		if p.peek_tok.kind in [.assign, .decl_assign] {
			init = p.var_decl_and_assign_stmt()
		}
		else if p.tok.kind != .semicolon {}
		// allow `for ;; i++ {`
		// Allow `for i = 0; i < ...`
		/*
			cond, typ = p.expr(0)
			if typ.kind != _bool {
				p.error('non-bool used as for condition')
			}
			*/
		// println(1)
		// }
		p.check(.semicolon)
		if p.tok.kind != .semicolon {
			mut typ := table.void_type
			cond,typ = p.expr(0)
		}
		p.check(.semicolon)
		if p.tok.kind != .lcbr {
			inc = p.stmt()
		}
		stmts := p.parse_block()
		p.close_scope()
		return ast.ForCStmt{
			stmts: stmts
			init: init
			cond: cond
			inc: inc
		}
	}
	// `for i in vals`, `for i in start .. end`
	else if p.peek_tok.kind in [.key_in, .comma] {
		var_name := p.check_name()
		mut val_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.scope.register_var(ast.VarDecl{
				name: val_name
				typ: table.int_type
			})
		}
		p.check(.key_in)
		mut elem_type := table.void_type
		// arr_expr
		cond,arr_typ := p.expr(0)
		// array / map
		if table.type_idx(arr_typ) == table.string_type_idx {
			elem_type = table.byte_type
		}
		else {
			arr_typ_sym := p.table.get_type_symbol(arr_typ)
			match arr_typ_sym.info {
				table.Array {
					elem_type = it.elem_type
				}
				table.Map {
					elem_type = it.value_type
				}
				else {}
				// println(1)
				// elem_type_sym := p.table.get_type_symbol(elem_type)
				// p.error('cannot loop over type: $elem_type_sym.name')
				// }
			}
		}
		// 0 .. 10
		// start := p.tok.lit.int()
		// TODO use RangeExpr
		mut high_expr := ast.Expr{}
		mut is_range := false
		if p.tok.kind == .dotdot {
			is_range = true
			p.check(.dotdot)
			high_expr,_ = p.expr(0)
		}
		// p.table.register_var(table.Var{
		// name: var_name
		// typ: elem_type
		// })
		p.scope.register_var(ast.VarDecl{
			name: var_name
			typ: elem_type
		})
		stmts := p.parse_block()
		// println('nr stmts=$stmts.len')
		p.close_scope()
		return ast.ForInStmt{
			stmts: stmts
			pos: p.tok.position()
			cond: cond
			key_var: var_name
			val_var: val_name
			high: high_expr
			is_range: is_range
		}
	}
	// `for cond {`
	cond,_ := p.expr(0)
	stmts := p.parse_block()
	p.close_scope()
	return ast.ForStmt{
		cond: cond
		stmts: stmts
		pos: p.tok.position()
	}
}

fn (p mut Parser) if_expr() ast.Expr {
	p.inside_if = true
	// defer {
	// }
	mut node := ast.Expr{}
	p.check(.key_if)
	pos := p.tok.position()
	// `if x := opt() {`
	mut cond := ast.Expr{}
	mut is_or := false
	if p.peek_tok.kind == .decl_assign {
		is_or = true
		p.open_scope()
		var_name := p.check_name()
		// p.table.register_var(
		p.check(.decl_assign)
		expr,typ := p.expr(0)
		p.scope.register_var(ast.VarDecl{
			name: var_name
			typ: typ
		})
		cond = ast.IfGuardExpr{
			var_name: var_name
			expr: expr
		}
	}
	else {
		cond,_ = p.expr(0)
	}
	p.inside_if = false
	mut has_else := false
	stmts := p.parse_block()
	mut else_stmts := []ast.Stmt
	if p.tok.kind == .key_else {
		p.check(.key_else)
		if p.tok.kind == .key_if {
			// The next if block is handled by next if_expr()
			has_else = true
		}
		// p.if_expr()
		else {
			else_stmts = p.parse_block()
		}
	}
	if is_or {
		p.close_scope()
	}
	// mut typ := table.void_type
	// mut left := ast.Expr{}
	// If the last statement is an expression, return its type
	/*
	if stmts.len > 0 {
		match stmts[stmts.len - 1] {
			ast.ExprStmt {
				type_sym := p.table.get_type_symbol(it.typ)
				p.warn('if expr ret $type_sym.name')
				typ = it.typ
				// return node,it.ti
				// left =
			}
			else {}
	}
	}
	*/

	node = ast.IfExpr{
		cond: cond
		stmts: stmts
		else_stmts: else_stmts
		// typ: typ
		
		pos: pos
		has_else: has_else
		// left: left
		
	}
	return node
}

fn (p mut Parser) string_expr() (ast.Expr,table.Type) {
	mut node := ast.Expr{}
	node = ast.StringLiteral{
		val: p.tok.lit
	}
	if p.peek_tok.kind != .str_dollar {
		p.next()
		return node,table.string_type
	}
	// Handle $ interpolation
	for p.tok.kind == .str {
		p.next()
		if p.tok.kind != .str_dollar {
			continue
		}
		p.check(.str_dollar)
		p.expr(0)
		if p.tok.kind == .colon {
			p.next()
		}
		// ${num:2d}
		if p.tok.kind == .number {
			p.next()
			if p.tok.lit.len == 1 {
				p.next()
			}
		}
	}
	return node,table.string_type
}

fn (p mut Parser) array_init() ast.ArrayInit {
	p.check(.lsbr)
	// `[]` - empty array with an automatically deduced type
	// p.warn('array_init() exp=$p.expected_type')
	/*
	if p.expected_type != 0 {
		sym := p.table.get_type_symbol(p.expected_type)
		println(sym.name)
	}
	*/
	/* TODO: joe
	if p.tok.kind == .rsbr && int(p.expected_type) != 0 && p.table.get_type_symbol(p.expected_type).kind == .array {
		// p.warn('[] expr')
		node = ast.ArrayInit{
			// typ: array_type
			exprs: []
			pos: p.tok.position()
		}
		p.check(.rsbr)
		return node,p.expected_type
	}
	*/

	mut array_type := table.Type(0)
	mut exprs := []ast.Expr
	// mut is_fixed := false
	// mut fixed_size := 0
	if p.tok.kind == .rsbr {
		// []typ => `[]` and `typ` must be on the same line
		line_nr := p.tok.line_nr
		p.check(.rsbr)
		// []string
		if p.tok.kind == .name && p.tok.line_nr == line_nr {
			val_type := p.parse_type()
			// this is set here becasue its a known type, others could be the
			// result of expr so we do those in checker
			idx := p.table.find_or_register_array(val_type, 1)
			array_type = table.new_type(idx)
		}
		// []
		else {}
		// TODO ?
	}
	else {
		// [1,2,3]
		for i := 0; p.tok.kind != .rsbr; i++ {
			expr,_ := p.expr(0)
			exprs << expr
			if p.tok.kind == .comma {
				p.check(.comma)
			}
		}
		// line_nr := p.tok.line_nr
		p.check(.rsbr)
		// Fixed size array? (`[100]byte`)
		// NOTE: this should be hanled in parse_type() ?
		/*
		if exprs.len == 1 && p.tok.kind == .name && p.tok.line_nr == line_nr {
			is_fixed = true
			val_type = p.parse_type()
			match exprs[0] {
				ast.IntegerLiteral {
					fixed_size = it.val
				}
				else {}
			}
			p.warn('fixed size array')
		}
		*/

	}
	// !
	if p.tok.kind == .not {
		p.next()
	}
	if p.tok.kind == .not {
		p.next()
	}
	// idx := if is_fixed { p.table.find_or_register_array_fixed(val_type, fixed_size, 1) } else { p.table.find_or_register_array(val_type, 1) }
	// array_type := table.new_type(idx)
	return ast.ArrayInit{
		typ: array_type
		exprs: exprs
		pos: p.tok.position()
	}
}

fn (p mut Parser) parse_number_literal() (ast.Expr,table.Type) {
	lit := p.tok.lit
	mut node := ast.Expr{}
	mut typ := table.int_type
	if lit.contains('.') {
		node = ast.FloatLiteral{
			// val: lit.f64()
			val: lit
		}
		typ = table.f64_type
	}
	else {
		node = ast.IntegerLiteral{
			val: lit.int()
		}
	}
	p.next()
	return node,typ
}

fn (p mut Parser) module_decl() ast.Module {
	p.check(.key_module)
	mod := p.check_name()
	full_mod := p.table.qualify_module(mod, p.file_name)
	p.mod = full_mod
	return ast.Module{
		name: full_mod
	}
}

fn (p mut Parser) parse_import() ast.Import {
	mut mod_name := p.check_name()
	mut mod_alias := mod_name
	for p.tok.kind == .dot {
		p.check(.dot)
		submod_name := p.check_name()
		mod_name += '.' + submod_name
		mod_alias = submod_name
	}
	if p.tok.kind == .key_as {
		p.check(.key_as)
		mod_alias = p.check_name()
	}
	p.imports[mod_alias] = mod_name
	p.table.imports << mod_name
	return ast.Import{
		mod: mod_name
		alias: mod_alias
		pos: p.tok.position()
	}
}

fn (p mut Parser) import_stmt() []ast.Import {
	p.check(.key_import)
	mut imports := []ast.Import
	if p.tok.kind == .lpar {
		p.check(.lpar)
		for p.tok.kind != .rpar {
			imports << p.parse_import()
		}
		p.check(.rpar)
	}
	else {
		imports << p.parse_import()
	}
	return imports
}

fn (p mut Parser) const_decl() ast.ConstDecl {
	is_pub := p.tok.kind == .key_pub
	if is_pub {
		p.next()
	}
	p.check(.key_const)
	p.check(.lpar)
	mut fields := []ast.Field
	mut exprs := []ast.Expr
	for p.tok.kind != .rpar {
		name := p.prepend_mod(p.check_name())
		// println('!!const: $name')
		p.check(.assign)
		expr,typ := p.expr(0)
		fields << ast.Field{
			name: name
			typ: typ
		}
		exprs << expr
		p.table.register_const(table.Var{
			name: name
			typ: typ
		})
	}
	p.check(.rpar)
	return ast.ConstDecl{
		fields: fields
		exprs: exprs
		is_pub: is_pub
	}
}

// structs and unions
fn (p mut Parser) struct_decl() ast.StructDecl {
	is_pub := p.tok.kind == .key_pub
	if is_pub {
		p.next()
	}
	if p.tok.kind == .key_struct {
		p.check(.key_struct)
	}
	else {
		p.check(.key_union)
	}
	is_c := p.tok.lit == 'C' && p.peek_tok.kind == .dot
	if is_c {
		p.next() // C
		p.next() // .
	}
	name := p.check_name()
	p.check(.lcbr)
	mut ast_fields := []ast.Field
	mut fields := []table.Field
	mut mut_pos := -1
	mut pub_pos := -1
	mut pub_mut_pos := -1
	for p.tok.kind != .rcbr {
		if p.tok.kind == .key_pub {
			p.check(.key_pub)
			if p.tok.kind == .key_mut {
				p.check(.key_mut)
				pub_mut_pos = fields.len
			}
			else {
				pub_pos = fields.len
			}
			p.check(.colon)
		}
		else if p.tok.kind == .key_mut {
			p.check(.key_mut)
			p.check(.colon)
			mut_pos = fields.len
		}
		field_name := p.check_name()
		// p.warn('field $field_name')
		typ := p.parse_type()
		// Default value
		if p.tok.kind == .assign {
			p.next()
			p.expr(0)
		}
		ast_fields << ast.Field{
			name: field_name
			typ: typ
		}
		fields << table.Field{
			name: field_name
			typ: typ
		}
		// println('struct field $ti.name $field_name')
	}
	p.check(.rcbr)
	t := table.TypeSymbol{
		kind: .struct_
		name: p.prepend_mod(name)
		info: table.Struct{
			fields: fields
		}
	}
	mut ret := 0
	if p.builtin_mod && t.name in table.builtin_type_names {
		// this allows overiding the builtins type
		// with the real struct type info parsed from builtin
		ret = p.table.register_builtin_type_symbol(t)
	}
	else {
		ret = p.table.register_type_symbol(t)
	}
	if ret == -1 {
		p.error('cannot register type `$name`, another type with this name exists')
	}
	p.expr_mod = ''
	return ast.StructDecl{
		name: name
		is_pub: is_pub
		fields: ast_fields
		pos: p.tok.position()
		mut_pos: mut_pos
		pub_pos: pub_pos
		pub_mut_pos: pub_mut_pos
	}
}

fn (p mut Parser) return_stmt() ast.Return {
	p.next()
	// return expressions
	mut exprs := []ast.Expr
	// return type idents
	// mut got_tis := []table.Type
	if table.type_idx(p.return_type) == table.void_type_idx {
		return ast.Return{
			pos: p.tok.position()
		}
	}
	for {
		// expr,ti := p.expr(0)
		expr,_ := p.expr(0)
		exprs << expr
		// got_tis << ti
		if p.tok.kind == .comma {
			p.check(.comma)
		}
		else {
			break
		}
	}
	stmt := ast.Return{
		expected_type: p.return_type
		exprs: exprs
		pos: p.tok.position()
	}
	return stmt
}

// left hand side of `=` or `:=` in `a,b,c := 1,2,3`
fn (p mut Parser) parse_assign_lhs() []ast.Ident {
	mut idents := []ast.Ident
	for {
		is_mut := p.tok.kind == .key_mut
		if is_mut {
			p.check(.key_mut)
		}
		is_static := p.tok.kind == .key_static
		if is_static {
			p.check(.key_static)
		}
		mut ident := p.parse_ident(false)
		ident.info = ast.IdentVar{
			is_mut: is_mut
			is_static: is_static
		}
		idents << ident
		if p.tok.kind == .comma {
			p.check(.comma)
		}
		else {
			break
		}
	}
	return idents
}

// right hand side of `=` or `:=` in `a,b,c := 1,2,3`
fn (p mut Parser) parse_assign_rhs() []ast.Expr {
	mut exprs := []ast.Expr
	for {
		expr,_ := p.expr(0)
		exprs << expr
		if p.tok.kind == .comma {
			p.check(.comma)
		}
		else {
			break
		}
	}
	return exprs
}

fn (p mut Parser) var_decl_and_assign_stmt() ast.Stmt {
	idents := p.parse_assign_lhs()
	op := p.tok.kind
	p.next() // :=, =
	exprs := p.parse_assign_rhs()
	is_decl := op == .decl_assign
	// VarDecl
	if idents.len == 1 {
		ident := idents[0]
		expr := exprs[0]
		info0 := ident.var_info()
		known_var := p.scope.known_var(ident.name)
		if !is_decl && !known_var {
			p.error('unknown variable `$ident.name`')
		}
		if is_decl && ident.kind != .blank_ident {
			if known_var {
				p.error('redefinition of `$ident.name`')
			}
			p.scope.register_var(ast.VarDecl{
				name: ident.name
				expr: expr
			})
		}
		return ast.VarDecl{
			name: ident.name
			// name2: name2
			
			expr: expr // p.expr(token.lowest_prec)
			
			is_mut: info0.is_mut
			// typ: typ
			
			pos: p.tok.position()
		}
		// return p.var_decl(ident[0], exprs[0])
	}
	// AssignStmt
	for ident in idents {
		if is_decl && ident.kind != .blank_ident {
			if p.scope.known_var(ident.name) {
				p.error('redefinition of `$ident.name`')
			}
			p.scope.register_var(ast.VarDecl{
				name: ident.name
			})
		}
	}
	return ast.AssignStmt{
		left: idents
		right: exprs
		op: op
		pos: p.tok.position()
	}
}

// pub fn (p mut Parser) assign_stmt() ast.AssignStmt {}
// fn (p mut Parser) var_decl() ast.VarDecl {}
fn (p mut Parser) hash() ast.HashStmt {
	p.next()
	return ast.HashStmt{
		name: p.tok.lit
	}
}

fn (p mut Parser) global_decl() ast.GlobalDecl {
	if !p.pref.translated && !p.pref.is_live && !p.builtin_mod && !p.pref.building_v && p.mod != 'ui' && p.mod != 'gg2' && p.mod != 'uiold' && !os.getwd().contains('/volt') && !p.pref.enable_globals {
		p.error('use `v --enable-globals ...` to enable globals')
	}
	p.next()
	name := p.check_name()
	println(name)
	typ := p.parse_type()
	if p.tok.kind == .assign {
		p.next()
		p.expr(0)
	}
	p.table.register_global(name, typ)
	// p.genln(p.table.cgen_name_type_pair(name, typ))
	/*
		mut g := p.table.cgen_name_type_pair(name, typ)
		if p.tok == .assign {
			p.next()
			g += ' = '
			_,expr := p.tmp_expr()
			g += expr
		}
		// p.genln('; // global')
		g += '; // global'
		if !p.cgen.nogen {
			p.cgen.consts << g
		}
		*/

	return ast.GlobalDecl{
		name: name
	}
}

fn (p mut Parser) match_expr() ast.Expr {
	p.check(.key_match)
	is_mut := p.tok.kind == .key_mut
	if is_mut {
		p.next()
	}
	cond,_ := p.expr(0)
	// sym := p.table.get_type_symbol(typ)
	// p.warn('match typ $sym.name')
	p.check(.lcbr)
	mut blocks := []ast.StmtBlock
	mut match_exprs := []ast.Expr
	// mut return_type := table.void_type
	for {
		// Sum type match
		if p.tok.kind == .name && (p.tok.lit[0].is_capital() || p.peek_tok.kind == .dot) {
			// if sym.kind == .sum_type {
			// p.warn('is sum')
			// p.parse_type()
			p.check_name()
			if p.tok.kind == .dot {
				p.check(.dot)
				p.check_name()
			}
		}
		else {
			// Expression match
			for {
				match_expr,_ := p.expr(0)
				match_exprs << match_expr
				if p.tok.kind != .comma {
					break
				}
				p.check(.comma)
			}
		}
		// p.warn('match block')
		stmts := p.parse_block()
		blocks << ast.StmtBlock{
			stmts: stmts
		}
		if p.tok.kind == .key_else {
			p.next()
			blocks << ast.StmtBlock{
				stmts: p.parse_block()
			}
		}
		// If the last statement is an expression, return its type
		/*
		if stmts.len > 0 {
			match stmts[stmts.len - 1] {
				ast.ExprStmt {
					type_sym := p.table.get_type_symbol(it.typ)
					p.warn('match expr ret $type_sym.name')
					return_type = it.typ
				}
				else {}
			}
		}
		*/

		if p.tok.kind == .rcbr {
			break
		}
	}
	p.check(.rcbr)
	mut node := ast.Expr{}
	node = ast.MatchExpr{
		blocks: blocks
		match_exprs: match_exprs
		// typ: typ
		
		cond: cond
	}
	return node
	// return node,return_type
}

fn (p mut Parser) enum_decl() ast.EnumDecl {
	is_pub := p.tok.kind == .key_pub
	if is_pub {
		p.next()
	}
	p.check(.key_enum)
	name := p.check_name()
	p.check(.lcbr)
	mut vals := []string
	for p.tok.kind != .eof && p.tok.kind != .rcbr {
		val := p.check_name()
		vals << val
		// p.warn('enum val $val')
		if p.tok.kind == .assign {
			p.next()
			p.expr(0)
		}
	}
	p.check(.rcbr)
	p.table.register_type_symbol(table.TypeSymbol{
		kind: .enum_
		name: p.prepend_mod(name)
		info: table.Enum{
			vals: vals
		}
	})
	return ast.EnumDecl{
		name: name
		is_pub: is_pub
		vals: vals
	}
}

fn (p mut Parser) type_decl() ast.TypeDecl {
	is_pub := p.tok.kind == .key_pub
	if is_pub {
		p.next()
	}
	p.check(.key_type)
	name := p.check_name()
	mut is_sum := false
	// type SumType = A | B | c
	if p.tok.kind == .assign {
		p.next()
		for {
			p.check_name()
			if p.tok.kind != .pipe {
				break
			}
			p.check(.pipe)
			is_sum = true
		}
	}
	else {
		p.parse_type()
	}
	p.table.register_type_symbol(table.TypeSymbol{
		kind: .sum_type
		name: name
		info: table.Alias{
			foo: ''
		}
	})
	return ast.TypeDecl{
		name: name
	}
}

fn verror(s string) {
	println(s)
	exit(1)
}