662 lines
15 KiB
V
662 lines
15 KiB
V
// Copyright (c) 2019-2022 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module parser
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import v.ast
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import v.vet
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import v.token
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pub fn (mut p Parser) expr(precedence int) ast.Expr {
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return p.check_expr(precedence) or {
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p.error_with_pos('invalid expression: unexpected $p.tok', p.tok.pos())
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}
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}
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pub fn (mut p Parser) check_expr(precedence int) ?ast.Expr {
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p.trace_parser('expr($precedence)')
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mut node := ast.empty_expr()
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is_stmt_ident := p.is_stmt_ident
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p.is_stmt_ident = false
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if !p.pref.is_fmt {
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p.eat_comments()
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}
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inside_array_lit := p.inside_array_lit
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p.inside_array_lit = false
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defer {
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p.inside_array_lit = inside_array_lit
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}
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// Prefix
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match p.tok.kind {
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.key_mut, .key_shared, .key_atomic, .key_static, .key_volatile {
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ident := p.parse_ident(ast.Language.v)
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node = ident
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if p.inside_defer {
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if !p.defer_vars.any(it.name == ident.name && it.mod == ident.mod)
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&& ident.name != 'err' {
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p.defer_vars << ident
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}
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}
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p.is_stmt_ident = is_stmt_ident
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}
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.name, .question {
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if p.tok.lit == 'sql' && p.peek_tok.kind == .name {
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p.inside_match = true // reuse the same var for perf instead of inside_sql TODO rename
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node = p.sql_expr()
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p.inside_match = false
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} else if p.tok.lit == 'map' && p.peek_tok.kind == .lcbr && !(p.builtin_mod
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&& p.file_base in ['map.v', 'map_d_gcboehm_opt.v']) {
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p.error_with_pos("deprecated map syntax, use syntax like `{'age': 20}`",
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p.tok.pos())
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} else {
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if p.inside_if && p.is_generic_name() && p.peek_tok.kind != .dot {
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// $if T is string {}
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p.expecting_type = true
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}
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node = p.name_expr()
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p.is_stmt_ident = is_stmt_ident
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}
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}
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.string {
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node = p.string_expr()
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}
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.comment {
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node = p.comment()
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return node
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}
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.dot {
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// .enum_val
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node = p.enum_val()
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}
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.at {
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node = p.at()
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}
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.dollar {
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match p.peek_tok.kind {
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.name {
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if p.peek_tok.lit in comptime_types {
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node = p.parse_comptime_type()
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} else {
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node = p.comptime_call()
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}
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p.is_stmt_ident = is_stmt_ident
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}
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.key_if {
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return p.if_expr(true)
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}
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else {
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return p.error_with_pos('unexpected `$`', p.peek_tok.pos())
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}
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}
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}
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.chartoken {
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node = ast.CharLiteral{
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val: p.tok.lit
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pos: p.tok.pos()
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}
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p.next()
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}
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.amp, .mul, .not, .bit_not, .arrow {
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// &x, *x, !x, ~x, <-x
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node = p.prefix_expr()
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}
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.minus {
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// -1, -a
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if p.peek_tok.kind == .number {
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node = p.parse_number_literal()
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} else {
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node = p.prefix_expr()
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}
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}
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.key_go {
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mut go_expr := p.go_expr()
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go_expr.is_expr = true
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node = go_expr
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}
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.key_true, .key_false {
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node = ast.BoolLiteral{
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val: p.tok.kind == .key_true
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pos: p.tok.pos()
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}
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p.next()
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}
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.key_match {
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node = p.match_expr()
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}
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.key_select {
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node = p.select_expr()
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}
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.number {
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node = p.parse_number_literal()
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}
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.lpar {
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mut pos := p.tok.pos()
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p.check(.lpar)
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node = p.expr(0)
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p.check(.rpar)
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node = ast.ParExpr{
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expr: node
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pos: pos.extend(p.prev_tok.pos())
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}
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}
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.key_if {
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node = p.if_expr(false)
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}
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.key_unsafe {
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// unsafe {
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mut pos := p.tok.pos()
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p.next()
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if p.inside_unsafe {
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return p.error_with_pos('already inside `unsafe` block', pos)
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}
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p.inside_unsafe = true
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p.check(.lcbr)
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e := p.expr(0)
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p.check(.rcbr)
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pos.update_last_line(p.prev_tok.line_nr)
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node = ast.UnsafeExpr{
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expr: e
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pos: pos
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}
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p.inside_unsafe = false
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}
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.key_lock, .key_rlock {
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node = p.lock_expr()
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}
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.lsbr {
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if p.expecting_type {
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// parse json.decode type (`json.decode([]User, s)`)
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node = p.name_expr()
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} else if p.is_amp && p.peek_tok.kind == .rsbr && p.peek_token(3).kind != .lcbr {
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pos := p.tok.pos()
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typ := p.parse_type()
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typname := p.table.sym(typ).name
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p.check(.lpar)
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expr := p.expr(0)
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p.check(.rpar)
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node = ast.CastExpr{
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typ: typ
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typname: typname
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expr: expr
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pos: pos
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}
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} else {
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node = p.array_init()
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}
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}
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.key_none {
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pos := p.tok.pos()
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p.next()
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node = ast.None{
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pos: pos
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}
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}
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.key_sizeof, .key_isreftype {
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is_reftype := p.tok.kind == .key_isreftype
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p.next() // sizeof
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p.check(.lpar)
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pos := p.tok.pos()
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is_known_var := p.mark_var_as_used(p.tok.lit)
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|| p.table.global_scope.known_const(p.mod + '.' + p.tok.lit)
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//|| p.table.known_fn(p.mod + '.' + p.tok.lit)
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// assume `mod.` prefix leads to a type
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is_type := p.known_import(p.tok.lit) || p.tok.kind.is_start_of_type()
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|| (p.tok.lit.len > 0 && p.tok.lit[0].is_capital())
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if is_known_var || !is_type {
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expr := p.expr(0)
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if is_reftype {
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node = ast.IsRefType{
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is_type: false
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expr: expr
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pos: pos
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}
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} else {
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node = ast.SizeOf{
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is_type: false
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expr: expr
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pos: pos
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}
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}
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} else {
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if p.tok.kind == .name {
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p.register_used_import(p.tok.lit)
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}
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save_expr_mod := p.expr_mod
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p.expr_mod = ''
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arg_type := p.parse_type()
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p.expr_mod = save_expr_mod
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if is_reftype {
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node = ast.IsRefType{
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is_type: true
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typ: arg_type
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pos: pos
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}
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} else {
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node = ast.SizeOf{
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is_type: true
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typ: arg_type
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pos: pos
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}
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}
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}
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p.check(.rpar)
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}
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.key_typeof {
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spos := p.tok.pos()
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p.next()
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p.check(.lpar)
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expr := p.expr(0)
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p.check(.rpar)
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if p.tok.kind != .dot && p.tok.line_nr == p.prev_tok.line_nr {
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p.warn_with_pos('use e.g. `typeof(expr).name` or `sum_type_instance.type_name()` instead',
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spos)
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}
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node = ast.TypeOf{
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expr: expr
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pos: spos.extend(p.tok.pos())
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}
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}
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.key_dump {
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spos := p.tok.pos()
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p.next()
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p.check(.lpar)
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expr := p.expr(0)
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p.check(.rpar)
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node = ast.DumpExpr{
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expr: expr
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pos: spos.extend(p.tok.pos())
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}
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}
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.key_offsetof {
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pos := p.tok.pos()
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p.next() // __offsetof
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p.check(.lpar)
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st := p.parse_type()
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p.check(.comma)
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if p.tok.kind != .name {
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return p.error_with_pos('unexpected `$p.tok.lit`, expecting struct field',
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p.tok.pos())
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}
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field := p.tok.lit
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p.next()
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p.check(.rpar)
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node = ast.OffsetOf{
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struct_type: st
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field: field
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pos: pos
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}
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}
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.key_likely, .key_unlikely {
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is_likely := p.tok.kind == .key_likely
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p.next()
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p.check(.lpar)
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lpos := p.tok.pos()
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expr := p.expr(0)
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p.check(.rpar)
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node = ast.Likely{
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expr: expr
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pos: lpos
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is_likely: is_likely
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}
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}
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.lcbr {
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// Map `{"age": 20}`
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p.next()
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node = p.map_init()
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p.check(.rcbr)
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}
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.key_fn {
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if p.expecting_type {
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// Anonymous function type
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start_pos := p.tok.pos()
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return ast.TypeNode{
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typ: p.parse_type()
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pos: start_pos.extend(p.prev_tok.pos())
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}
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} else {
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// Anonymous function
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node = p.anon_fn()
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// its a call
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// NOTE: this could be moved to just before the pratt loop
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// then anything can be a call, eg. `index[2]()` or `struct.field()`
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// but this would take a bit of modification
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if p.tok.kind == .lpar {
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p.next()
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pos := p.tok.pos()
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args := p.call_args()
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p.check(.rpar)
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node = ast.CallExpr{
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name: 'anon'
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left: node
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args: args
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pos: pos
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scope: p.scope
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}
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}
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return node
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}
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}
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else {
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if p.tok.kind != .eof && !(p.tok.kind == .rsbr && p.inside_asm) {
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// eof should be handled where it happens
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return none
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// return p.error_with_pos('invalid expression: unexpected $p.tok', p.tok.pos())
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}
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}
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}
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if inside_array_lit {
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if p.tok.kind in [.minus, .mul, .amp, .arrow] && p.tok.pos + 1 == p.peek_tok.pos
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&& p.prev_tok.pos + p.prev_tok.len + 1 != p.peek_tok.pos {
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return node
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}
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}
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return p.expr_with_left(node, precedence, is_stmt_ident)
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}
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pub fn (mut p Parser) expr_with_left(left ast.Expr, precedence int, is_stmt_ident bool) ast.Expr {
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mut node := left
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if p.inside_asm && p.prev_tok.pos().line_nr < p.tok.pos().line_nr {
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return node
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}
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// Infix
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for precedence < p.tok.precedence() {
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if p.tok.kind == .dot { //&& (p.tok.line_nr == p.prev_tok.line_nr
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// TODO fix a bug with prev_tok.last_line
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//|| p.prev_tok.pos().last_line == p.tok.line_nr) {
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// if p.fileis('vcache.v') {
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// p.warn('tok.line_nr = $p.tok.line_nr; prev_tok.line_nr=$p.prev_tok.line_nr;
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// prev_tok.last_line=$p.prev_tok.pos().last_line')
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//}
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node = p.dot_expr(node)
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if p.name_error {
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return node
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}
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p.is_stmt_ident = is_stmt_ident
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} else if p.tok.kind in [.lsbr, .nilsbr] && p.tok.line_nr == p.prev_tok.line_nr {
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if p.tok.kind == .nilsbr {
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node = p.index_expr(node, true)
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} else {
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node = p.index_expr(node, false)
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}
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p.is_stmt_ident = is_stmt_ident
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if p.tok.kind == .lpar && p.tok.line_nr == p.prev_tok.line_nr && node is ast.IndexExpr {
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p.next()
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pos := p.tok.pos()
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args := p.call_args()
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p.check(.rpar)
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node = ast.CallExpr{
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left: node
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args: args
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pos: pos
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scope: p.scope
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}
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p.is_stmt_ident = is_stmt_ident
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}
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} else if p.tok.kind == .key_as {
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// sum type as cast `x := SumType as Variant`
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if !p.inside_asm {
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pos := p.tok.pos()
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p.next()
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typ := p.parse_type()
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node = ast.AsCast{
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expr: node
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typ: typ
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pos: pos
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}
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} else {
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return node
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}
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} else if p.tok.kind == .left_shift && p.is_stmt_ident {
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// arr << elem
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tok := p.tok
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mut pos := tok.pos()
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p.next()
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right := p.expr(precedence - 1)
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pos.update_last_line(p.prev_tok.line_nr)
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if mut node is ast.IndexExpr {
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node.recursive_mapset_is_setter(true)
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}
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node = ast.InfixExpr{
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left: node
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right: right
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op: tok.kind
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pos: pos
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is_stmt: true
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}
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} else if p.tok.kind.is_infix() {
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if p.tok.kind.is_prefix() && p.tok.line_nr != p.prev_tok.line_nr {
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// return early for deref assign `*x = 2` goes to prefix expr
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if p.tok.kind == .mul && p.peek_token(2).kind == .assign {
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return node
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}
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// added 10/2020: LATER this will be parsed as PrefixExpr instead
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p.warn_with_pos('move infix `$p.tok.kind` operator before new line (if infix intended) or use brackets for a prefix expression',
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p.tok.pos())
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}
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// continue on infix expr
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node = p.infix_expr(node)
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// return early `if bar is SumType as b {`
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if p.tok.kind == .key_as && p.inside_if {
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return node
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}
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} else if p.tok.kind in [.inc, .dec] || (p.tok.kind == .question && p.inside_ct_if_expr) {
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// Postfix
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// detect `f(x++)`, `a[x++]`
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if p.peek_tok.kind in [.rpar, .rsbr] {
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if !p.inside_ct_if_expr {
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p.warn_with_pos('`$p.tok.kind` operator can only be used as a statement',
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p.peek_tok.pos())
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}
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}
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if p.tok.kind in [.inc, .dec] && p.prev_tok.line_nr != p.tok.line_nr {
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p.error_with_pos('$p.tok must be on the same line as the previous token',
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p.tok.pos())
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}
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if mut node is ast.IndexExpr {
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node.recursive_mapset_is_setter(true)
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}
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node = ast.PostfixExpr{
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op: p.tok.kind
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expr: node
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pos: p.tok.pos()
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}
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p.next()
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// return node // TODO bring back, only allow ++/-- in exprs in translated code
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} else {
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return node
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}
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}
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return node
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}
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fn (mut p Parser) infix_expr(left ast.Expr) ast.Expr {
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op := p.tok.kind
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if op == .arrow {
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p.or_is_handled = true
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p.register_auto_import('sync')
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}
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precedence := p.tok.precedence()
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mut pos := p.tok.pos()
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p.next()
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mut right := ast.empty_expr()
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prev_expecting_type := p.expecting_type
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if op in [.key_is, .not_is] {
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p.expecting_type = true
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}
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is_key_in := op in [.key_in, .not_in]
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if is_key_in {
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p.inside_in_array = true
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}
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right = p.expr(precedence)
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if is_key_in {
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p.inside_in_array = false
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}
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p.expecting_type = prev_expecting_type
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if p.pref.is_vet && op in [.key_in, .not_in] && right is ast.ArrayInit
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&& (right as ast.ArrayInit).exprs.len == 1 {
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p.vet_error('Use `var == value` instead of `var in [value]`', pos.line_nr, vet.FixKind.vfmt,
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.default)
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}
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mut or_stmts := []ast.Stmt{}
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mut or_kind := ast.OrKind.absent
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mut or_pos := p.tok.pos()
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// allow `x := <-ch or {...}` to handle closed channel
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if op == .arrow {
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if p.tok.kind == .key_orelse {
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was_inside_or_expr := p.inside_or_expr
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p.inside_or_expr = true
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p.next()
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p.open_scope()
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p.scope.register(ast.Var{
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name: 'err'
|
|
typ: ast.error_type
|
|
pos: p.tok.pos()
|
|
is_used: true
|
|
is_stack_obj: true
|
|
})
|
|
or_kind = .block
|
|
or_stmts = p.parse_block_no_scope(false)
|
|
or_pos = or_pos.extend(p.prev_tok.pos())
|
|
p.close_scope()
|
|
p.inside_or_expr = was_inside_or_expr
|
|
}
|
|
if p.tok.kind == .question {
|
|
p.next()
|
|
or_kind = .propagate
|
|
}
|
|
p.or_is_handled = false
|
|
}
|
|
pos.update_last_line(p.prev_tok.line_nr)
|
|
return ast.InfixExpr{
|
|
left: left
|
|
right: right
|
|
op: op
|
|
pos: pos
|
|
is_stmt: p.is_stmt_ident
|
|
or_block: ast.OrExpr{
|
|
stmts: or_stmts
|
|
kind: or_kind
|
|
pos: or_pos
|
|
}
|
|
}
|
|
}
|
|
|
|
fn (mut p Parser) go_expr() ast.GoExpr {
|
|
p.next()
|
|
spos := p.tok.pos()
|
|
expr := p.expr(0)
|
|
call_expr := if expr is ast.CallExpr {
|
|
expr
|
|
} else {
|
|
p.error_with_pos('expression in `go` must be a function call', expr.pos())
|
|
ast.CallExpr{
|
|
scope: p.scope
|
|
}
|
|
}
|
|
pos := spos.extend(p.prev_tok.pos())
|
|
p.register_auto_import('sync.threads')
|
|
p.table.gostmts++
|
|
return ast.GoExpr{
|
|
call_expr: call_expr
|
|
pos: pos
|
|
}
|
|
}
|
|
|
|
fn (p &Parser) fileis(s string) bool {
|
|
return p.file_name.contains(s)
|
|
}
|
|
|
|
fn (mut p Parser) prefix_expr() ast.Expr {
|
|
mut pos := p.tok.pos()
|
|
op := p.tok.kind
|
|
if op == .amp {
|
|
p.is_amp = true
|
|
}
|
|
if op == .arrow {
|
|
p.or_is_handled = true
|
|
p.register_auto_import('sync')
|
|
}
|
|
// if op == .mul && !p.inside_unsafe {
|
|
// p.warn('unsafe')
|
|
// }
|
|
p.next()
|
|
mut right := p.expr(int(token.Precedence.prefix))
|
|
p.is_amp = false
|
|
if op == .amp {
|
|
if mut right is ast.CastExpr {
|
|
// Handle &Type(x), as well as &&Type(x) etc:
|
|
p.recast_as_pointer(mut right, pos)
|
|
return right
|
|
}
|
|
if mut right is ast.SelectorExpr {
|
|
// Handle &Type(x).name :
|
|
if mut right.expr is ast.CastExpr {
|
|
p.recast_as_pointer(mut right.expr, pos)
|
|
return right
|
|
}
|
|
}
|
|
if mut right is ast.IndexExpr {
|
|
// Handle &u64(x)[idx] :
|
|
if mut right.left is ast.CastExpr {
|
|
p.recast_as_pointer(mut right.left, pos)
|
|
return right
|
|
}
|
|
}
|
|
if mut right is ast.ParExpr {
|
|
if right.expr is ast.StructInit {
|
|
p.note_with_pos('unnecessary `()`, use `&$right.expr` instead of `&($right.expr)`',
|
|
right.pos)
|
|
right = right.expr
|
|
}
|
|
}
|
|
}
|
|
mut or_stmts := []ast.Stmt{}
|
|
mut or_kind := ast.OrKind.absent
|
|
mut or_pos := p.tok.pos()
|
|
// allow `x := <-ch or {...}` to handle closed channel
|
|
if op == .arrow {
|
|
if p.tok.kind == .key_orelse {
|
|
was_inside_or_expr := p.inside_or_expr
|
|
p.inside_or_expr = true
|
|
p.next()
|
|
p.open_scope()
|
|
p.scope.register(ast.Var{
|
|
name: 'err'
|
|
typ: ast.error_type
|
|
pos: p.tok.pos()
|
|
is_used: true
|
|
is_stack_obj: true
|
|
})
|
|
or_kind = .block
|
|
or_stmts = p.parse_block_no_scope(false)
|
|
or_pos = or_pos.extend(p.prev_tok.pos())
|
|
p.close_scope()
|
|
p.inside_or_expr = was_inside_or_expr
|
|
}
|
|
if p.tok.kind == .question {
|
|
p.next()
|
|
or_kind = .propagate
|
|
}
|
|
p.or_is_handled = false
|
|
}
|
|
pos.update_last_line(p.prev_tok.line_nr)
|
|
return ast.PrefixExpr{
|
|
op: op
|
|
right: right
|
|
pos: pos
|
|
or_block: ast.OrExpr{
|
|
stmts: or_stmts
|
|
kind: or_kind
|
|
pos: or_pos
|
|
}
|
|
}
|
|
}
|
|
|
|
fn (mut p Parser) recast_as_pointer(mut cast_expr ast.CastExpr, pos token.Pos) {
|
|
cast_expr.typ = cast_expr.typ.ref()
|
|
cast_expr.typname = p.table.sym(cast_expr.typ).name
|
|
cast_expr.pos = pos.extend(cast_expr.pos)
|
|
}
|