mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
755 lines
15 KiB
Go
755 lines
15 KiB
Go
// Copyright (c) 2019 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 main
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import os
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import strings
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struct Scanner {
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mut:
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file_path string
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text string
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pos int
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line_nr int
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inside_string bool
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dollar_start bool // for hacky string interpolation TODO simplify
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dollar_end bool
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debug bool
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line_comment string
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started bool
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// vfmt fields
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fmt_out strings.Builder
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fmt_indent int
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fmt_line_empty bool
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prev_tok Token
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}
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fn new_scanner(file_path string) *Scanner {
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if !os.file_exists(file_path) {
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panic('"$file_path" doesn\'t exist')
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}
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mut raw_text := os.read_file(file_path) or {
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panic('scanner: failed to open "$file_path"')
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return &Scanner{}
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}
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// BOM check
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if raw_text.len >= 3 {
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c_text := raw_text.str
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if c_text[0] == 0xEF && c_text[1] == 0xBB && c_text[2] == 0xBF {
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// skip three BOM bytes
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offset_from_begin := 3
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raw_text = tos(c_text[offset_from_begin], C.strlen(c_text) - offset_from_begin)
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}
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}
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text := raw_text
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scanner := &Scanner {
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file_path: file_path
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text: text
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fmt_out: strings.new_builder(1000)
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}
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return scanner
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}
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// TODO remove once multiple return values are implemented
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struct ScanRes {
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tok Token
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lit string
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}
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fn scan_res(tok Token, lit string) ScanRes {
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return ScanRes{tok, lit}
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}
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fn (s mut Scanner) ident_name() string {
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start := s.pos
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for {
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s.pos++
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if s.pos >= s.text.len {
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break
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}
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c := s.text[s.pos]
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if !is_name_char(c) && !c.is_digit() {
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break
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}
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}
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name := s.text.substr(start, s.pos)
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s.pos--
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return name
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}
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fn (s mut Scanner) ident_hex_number() string {
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start_pos := s.pos
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s.pos += 2 // skip '0x'
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for {
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if s.pos >= s.text.len {
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break
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}
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c := s.text[s.pos]
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if !c.is_hex_digit() {
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break
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}
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s.pos++
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}
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number := s.text.substr(start_pos, s.pos)
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s.pos--
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return number
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}
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fn (s mut Scanner) ident_oct_number() string {
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start_pos := s.pos
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for {
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if s.pos >= s.text.len {
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break
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}
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c := s.text[s.pos]
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if c.is_digit() {
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if !c.is_oct_digit() {
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s.error('malformed octal constant')
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}
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} else {
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break
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}
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s.pos++
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}
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number := s.text.substr(start_pos, s.pos)
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s.pos--
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return number
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}
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fn (s mut Scanner) ident_dec_number() string {
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start_pos := s.pos
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// scan integer part
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for s.text[s.pos].is_digit() {
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s.pos++
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}
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// e.g. 1..9
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// we just return '1' and don't scan '..9'
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if s.expect('..', s.pos) {
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number := s.text.substr(start_pos, s.pos)
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s.pos--
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return number
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}
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// scan fractional part
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if s.text[s.pos] == `.` {
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s.pos++
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for s.text[s.pos].is_digit() {
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s.pos++
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}
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}
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// scan exponential part
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mut has_exponential_part := false
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if s.expect('e+', s.pos) || s.expect('e-', s.pos) {
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exp_start_pos := s.pos += 2
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for s.text[s.pos].is_digit() {
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s.pos++
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}
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if exp_start_pos == s.pos {
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s.error('exponent has no digits')
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}
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has_exponential_part = true
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}
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// error check: 1.23.4, 123.e+3.4
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if s.text[s.pos] == `.` {
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if has_exponential_part {
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s.error('exponential part should be integer')
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}
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else {
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s.error('too many decimal points in number')
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}
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}
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number := s.text.substr(start_pos, s.pos)
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s.pos--
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return number
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}
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fn (s mut Scanner) ident_number() string {
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if s.expect('0x', s.pos) {
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return s.ident_hex_number()
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}
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if s.expect('0.', s.pos) || s.expect('0e', s.pos) {
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return s.ident_dec_number()
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}
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if s.text[s.pos] == `0` {
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return s.ident_oct_number()
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}
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return s.ident_dec_number()
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}
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fn (s Scanner) has_gone_over_line_end() bool {
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mut i := s.pos-1
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for i >= 0 && !s.text[i].is_white() {
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i--
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}
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for i >= 0 && s.text[i].is_white() {
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if is_nl(s.text[i]) {
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return true
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}
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i--
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}
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return false
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}
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fn (s mut Scanner) skip_whitespace() {
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for s.pos < s.text.len && s.text[s.pos].is_white() {
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// Count \r\n as one line
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if is_nl(s.text[s.pos]) && !s.expect('\r\n', s.pos-1) {
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s.line_nr++
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}
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s.pos++
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}
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}
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fn (s mut Scanner) scan() ScanRes {
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if s.line_comment != '' {
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//s.fgenln('// LOL "$s.line_comment"')
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//s.line_comment = ''
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}
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if s.started {
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s.pos++
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}
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s.started = true
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if s.pos >= s.text.len {
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return scan_res(.eof, '')
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}
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// skip whitespace
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if !s.inside_string {
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s.skip_whitespace()
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}
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// End of $var, start next string
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if s.dollar_end {
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if s.text[s.pos] == `\'` {
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s.dollar_end = false
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return scan_res(.str, '')
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}
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s.dollar_end = false
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return scan_res(.str, s.ident_string())
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}
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s.skip_whitespace()
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// end of file
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if s.pos >= s.text.len {
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return scan_res(.eof, '')
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}
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// handle each char
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c := s.text[s.pos]
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mut nextc := `\0`
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if s.pos + 1 < s.text.len {
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nextc = s.text[s.pos + 1]
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}
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// name or keyword
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if is_name_char(c) {
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name := s.ident_name()
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// tmp hack to detect . in ${}
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// Check if not .eof to prevent panic
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next_char := if s.pos + 1 < s.text.len { s.text[s.pos + 1] } else { `\0` }
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if is_key(name) {
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return scan_res(key_to_token(name), '')
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}
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// 'asdf $b' => "b" is the last name in the string, dont start parsing string
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// at the next ', skip it
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if s.inside_string {
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if next_char == `\'` {
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s.pos++
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s.dollar_start = false
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s.inside_string = false
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}
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}
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if s.dollar_start && next_char != `.` {
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s.dollar_end = true
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s.dollar_start = false
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}
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if s.pos == 0 && next_char == ` ` {
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s.pos++
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//If a single letter name at the start of the file, increment
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//Otherwise the scanner would be stuck at s.pos = 0
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}
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return scan_res(.name, name)
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}
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// `123`, `.123`
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else if c.is_digit() || c == `.` && nextc.is_digit() {
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num := s.ident_number()
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return scan_res(.number, num)
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}
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// all other tokens
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switch c {
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case `+`:
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if nextc == `+` {
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s.pos++
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return scan_res(.inc, '')
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}
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else if nextc == `=` {
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s.pos++
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return scan_res(.plus_assign, '')
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}
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return scan_res(.plus, '')
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case `-`:
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if nextc == `-` {
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s.pos++
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return scan_res(.dec, '')
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}
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else if nextc == `=` {
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s.pos++
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return scan_res(.minus_assign, '')
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}
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return scan_res(.minus, '')
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case `*`:
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if nextc == `=` {
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s.pos++
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return scan_res(.mult_assign, '')
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}
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return scan_res(.mul, '')
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case `^`:
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if nextc == `=` {
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s.pos++
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return scan_res(.xor_assign, '')
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}
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return scan_res(.xor, '')
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case `%`:
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if nextc == `=` {
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s.pos++
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return scan_res(.mod_assign, '')
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}
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return scan_res(.mod, '')
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case `?`:
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return scan_res(.question, '')
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case `\'`:
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return scan_res(.str, s.ident_string())
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// TODO allow double quotes
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// case QUOTE:
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// return scan_res(.str, s.ident_string())
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case `\``:
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return scan_res(.chartoken, s.ident_char())
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case `(`:
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return scan_res(.lpar, '')
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case `)`:
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return scan_res(.rpar, '')
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case `[`:
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return scan_res(.lsbr, '')
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case `]`:
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return scan_res(.rsbr, '')
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case `{`:
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// Skip { in ${ in strings
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if s.inside_string {
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return s.scan()
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}
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return scan_res(.lcbr, '')
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case `$`:
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return scan_res(.dollar, '')
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case `}`:
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// s = `hello $name !`
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// s = `hello ${name} !`
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if s.inside_string {
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s.pos++
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// TODO UN.neEDED?
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if s.text[s.pos] == `\'` {
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s.inside_string = false
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return scan_res(.str, '')
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}
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return scan_res(.str, s.ident_string())
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}
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else {
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return scan_res(.rcbr, '')
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}
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case `&`:
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if nextc == `=` {
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s.pos++
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return scan_res(.and_assign, '')
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}
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if nextc == `&` {
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s.pos++
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return scan_res(.and, '')
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}
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return scan_res(.amp, '')
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case `|`:
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if nextc == `|` {
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s.pos++
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return scan_res(.logical_or, '')
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}
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if nextc == `=` {
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s.pos++
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return scan_res(.or_assign, '')
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}
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return scan_res(.pipe, '')
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case `,`:
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return scan_res(.comma, '')
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case `@`:
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s.pos++
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name := s.ident_name()
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if !is_key(name) {
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s.error('@ must be used before keywords (e.g. `@type string`)')
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}
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return scan_res(.name, name)
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case `\r`:
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if nextc == `\n` {
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s.pos++
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return scan_res(.nl, '')
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}
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case `\n`:
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return scan_res(.nl, '')
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case `.`:
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if nextc == `.` {
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s.pos++
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return scan_res(.dotdot, '')
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}
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return scan_res(.dot, '')
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case `#`:
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start := s.pos + 1
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for s.pos < s.text.len && s.text[s.pos] != `\n` {
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s.pos++
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}
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s.line_nr++
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hash := s.text.substr(start, s.pos)
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return scan_res(.hash, hash.trim_space())
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case `>`:
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if nextc == `=` {
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s.pos++
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return scan_res(.ge, '')
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}
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else if nextc == `>` {
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if s.pos + 2 < s.text.len && s.text[s.pos + 2] == `=` {
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s.pos += 2
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return scan_res(.righ_shift_assign, '')
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}
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s.pos++
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return scan_res(.righ_shift, '')
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}
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else {
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return scan_res(.gt, '')
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}
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case `<`:
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if nextc == `=` {
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s.pos++
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return scan_res(.le, '')
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}
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else if nextc == `<` {
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if s.pos + 2 < s.text.len && s.text[s.pos + 2] == `=` {
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s.pos += 2
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return scan_res(.left_shift_assign, '')
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}
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s.pos++
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return scan_res(.left_shift, '')
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}
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else {
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return scan_res(.lt, '')
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}
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case `=`:
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if nextc == `=` {
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s.pos++
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return scan_res(.eq, '')
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}
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else if nextc == `>` {
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s.pos++
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return scan_res(.arrow, '')
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}
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else {
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return scan_res(.assign, '')
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}
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case `:`:
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if nextc == `=` {
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s.pos++
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return scan_res(.decl_assign, '')
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}
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else {
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return scan_res(.colon, '')
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}
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case `;`:
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return scan_res(.semicolon, '')
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case `!`:
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if nextc == `=` {
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s.pos++
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return scan_res(.ne, '')
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}
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else {
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return scan_res(.not, '')
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}
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case `~`:
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return scan_res(.bit_not, '')
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case `/`:
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if nextc == `=` {
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s.pos++
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return scan_res(.div_assign, '')
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}
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if nextc == `/` {
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start := s.pos + 1
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for s.pos < s.text.len && s.text[s.pos] != `\n`{
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s.pos++
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}
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s.line_nr++
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s.line_comment = s.text.substr(start + 1, s.pos)
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s.line_comment = s.line_comment.trim_space()
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s.fgenln('// ${s.prev_tok.str()} "$s.line_comment"')
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// Skip the comment (return the next token)
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return s.scan()
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}
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// Multiline comments
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if nextc == `*` {
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start := s.pos
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mut nest_count := 1
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// Skip comment
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for nest_count > 0 {
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s.pos++
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if s.pos >= s.text.len {
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s.line_nr--
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s.error('comment not terminated')
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}
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if s.text[s.pos] == `\n` {
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s.line_nr++
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continue
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}
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if s.expect('/*', s.pos) {
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nest_count++
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continue
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}
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if s.expect('*/', s.pos) {
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nest_count--
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}
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}
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s.pos++
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end := s.pos + 1
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comm := s.text.substr(start, end)
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s.fgenln(comm)
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// Skip if not in fmt mode
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return s.scan()
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}
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return scan_res(.div, '')
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}
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$if windows {
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if c == `\0` {
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return scan_res(.eof, '')
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}
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}
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mut msg := 'invalid character `${c.str()}`'
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if c == `"` {
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msg += ', use \' to denote strings'
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}
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s.error(msg)
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return scan_res(.eof, '')
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}
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fn (s &Scanner) error(msg string) {
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file := s.file_path.all_after('/')
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println('panic: $file:${s.line_nr + 1}')
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println(msg)
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exit(1)
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}
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// println('array out of bounds $idx len=$a.len')
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// This is really bad. It needs a major clean up
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fn (s mut Scanner) ident_string() string {
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// println("\nidentString() at char=", string(s.text[s.pos]),
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// "chard=", s.text[s.pos], " pos=", s.pos, "txt=", s.text[s.pos:s.pos+7])
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mut start := s.pos
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s.inside_string = false
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slash := `\\`
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for {
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s.pos++
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if s.pos >= s.text.len {
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break
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}
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c := s.text[s.pos]
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prevc := s.text[s.pos - 1]
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// end of string
|
|
if c == `\'` && (prevc != slash || (prevc == slash && s.text[s.pos - 2] == slash)) {
|
|
// handle '123\\' slash at the end
|
|
break
|
|
}
|
|
if c == `\n` {
|
|
s.line_nr++
|
|
}
|
|
// Don't allow \0
|
|
if c == `0` && s.pos > 2 && s.text[s.pos - 1] == `\\` {
|
|
s.error('0 character in a string literal')
|
|
}
|
|
// Don't allow \x00
|
|
if c == `0` && s.pos > 5 && s.expect('\\x0', s.pos - 3) {
|
|
s.error('0 character in a string literal')
|
|
}
|
|
// ${var}
|
|
if c == `{` && prevc == `$` {
|
|
s.inside_string = true
|
|
// so that s.pos points to $ at the next step
|
|
s.pos -= 2
|
|
break
|
|
}
|
|
// $var
|
|
if (c.is_letter() || c == `_`) && prevc == `$` {
|
|
s.inside_string = true
|
|
s.dollar_start = true
|
|
s.pos -= 2
|
|
break
|
|
}
|
|
}
|
|
mut lit := ''
|
|
if s.text[start] == `\'` {
|
|
start++
|
|
}
|
|
mut end := s.pos
|
|
if s.inside_string {
|
|
end++
|
|
}
|
|
if start > s.pos{}
|
|
else {
|
|
lit = s.text.substr(start, end)
|
|
}
|
|
return lit
|
|
}
|
|
|
|
fn (s mut Scanner) ident_char() string {
|
|
start := s.pos
|
|
slash := `\\`
|
|
mut len := 0
|
|
for {
|
|
s.pos++
|
|
if s.pos >= s.text.len {
|
|
break
|
|
}
|
|
if s.text[s.pos] != slash {
|
|
len++
|
|
}
|
|
double_slash := s.expect('\\\\', s.pos - 2)
|
|
if s.text[s.pos] == `\`` && (s.text[s.pos - 1] != slash || double_slash) {
|
|
if double_slash {
|
|
len++
|
|
}
|
|
break
|
|
}
|
|
}
|
|
len--
|
|
c := s.text.substr(start + 1, s.pos)
|
|
if len != 1 {
|
|
u := c.ustring()
|
|
if u.len != 1 {
|
|
s.error('invalid character literal (more than one character: $len)')
|
|
}
|
|
}
|
|
return c
|
|
}
|
|
|
|
fn (s mut Scanner) peek() Token {
|
|
// save scanner state
|
|
pos := s.pos
|
|
line := s.line_nr
|
|
inside_string := s.inside_string
|
|
dollar_start := s.dollar_start
|
|
dollar_end := s.dollar_end
|
|
|
|
res := s.scan()
|
|
tok := res.tok
|
|
|
|
// restore scanner state
|
|
s.pos = pos
|
|
s.line_nr = line
|
|
s.inside_string = inside_string
|
|
s.dollar_start = dollar_start
|
|
s.dollar_end = dollar_end
|
|
return tok
|
|
}
|
|
|
|
fn (s mut Scanner) expect(want string, start_pos int) bool {
|
|
end_pos := start_pos + want.len
|
|
if start_pos < 0 || start_pos >= s.text.len {
|
|
return false
|
|
}
|
|
if end_pos < 0 || end_pos > s.text.len {
|
|
return false
|
|
}
|
|
for pos in start_pos..end_pos {
|
|
if s.text[pos] != want[pos-start_pos] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
fn (s mut Scanner) debug_tokens() {
|
|
s.pos = 0
|
|
s.debug = true
|
|
|
|
fname := s.file_path.all_after('/')
|
|
println('\n===DEBUG TOKENS $fname===')
|
|
|
|
for {
|
|
res := s.scan()
|
|
tok := res.tok
|
|
lit := res.lit
|
|
print(tok.str())
|
|
if lit != '' {
|
|
println(' `$lit`')
|
|
}
|
|
else {
|
|
println('')
|
|
}
|
|
if tok == .eof {
|
|
println('============ END OF DEBUG TOKENS ==================')
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
fn is_name_char(c byte) bool {
|
|
return c.is_letter() || c == `_`
|
|
}
|
|
|
|
fn is_nl(c byte) bool {
|
|
return c == `\r` || c == `\n`
|
|
}
|
|
|
|
fn (s mut Scanner) get_opening_bracket() int {
|
|
mut pos := s.pos
|
|
mut parentheses := 0
|
|
mut inside_string := false
|
|
|
|
for pos > 0 && s.text[pos] != `\n` {
|
|
if s.text[pos] == `)` && !inside_string {
|
|
parentheses++
|
|
}
|
|
if s.text[pos] == `(` && !inside_string {
|
|
parentheses--
|
|
}
|
|
if s.text[pos] == `\'` && s.text[pos - 1] != `\\` && s.text[pos - 1] != `\`` {
|
|
inside_string = !inside_string
|
|
}
|
|
if parentheses == 0 {
|
|
break
|
|
}
|
|
pos--
|
|
}
|
|
return pos
|
|
}
|
|
|
|
// Foo { bar: 3, baz: 'hi' } => '{ bar: 3, baz: "hi" }'
|
|
fn (s mut Scanner) create_type_string(T Type, name string) {
|
|
line := s.line_nr
|
|
inside_string := s.inside_string
|
|
mut newtext := '\'{ '
|
|
start := s.get_opening_bracket() + 1
|
|
end := s.pos
|
|
for i, field in T.fields {
|
|
if i != 0 {
|
|
newtext += ', '
|
|
}
|
|
newtext += '$field.name: ' + '$${name}.${field.name}'
|
|
}
|
|
newtext += ' }\''
|
|
s.text = s.text.substr(0, start) + newtext + s.text.substr(end, s.text.len)
|
|
s.pos = start - 2
|
|
s.line_nr = line
|
|
s.inside_string = inside_string
|
|
}
|