691 lines
22 KiB
V
691 lines
22 KiB
V
// Copyright (c) 2021 Lars Pontoppidan. All rights reserved.
|
|
// Use of this source code is governed by an MIT license
|
|
// that can be found in the LICENSE file.
|
|
module scanner
|
|
|
|
import toml.input
|
|
import toml.token
|
|
import toml.util
|
|
|
|
pub const (
|
|
digit_extras = [`_`, `.`, `x`, `o`, `b`, `e`, `E`]
|
|
end_of_text = u32(~0)
|
|
)
|
|
|
|
// Scanner contains the necessary fields for the state of the scan process.
|
|
// the task the scanner does is also refered to as "lexing" or "tokenizing".
|
|
// The Scanner methods are based on much of the work in `vlib/strings/textscanner`.
|
|
pub struct Scanner {
|
|
pub:
|
|
config Config
|
|
text string // the input TOML text
|
|
mut:
|
|
col int // current column number (x coordinate)
|
|
line_nr int = 1 // current line number (y coordinate)
|
|
pos int // current flat/index position in the `text` field
|
|
header_len int // Length, how many bytes of header was found
|
|
// Quirks
|
|
is_left_of_assign bool = true // indicates if the scanner is on the *left* side of an assignment
|
|
}
|
|
|
|
// State is a read-only copy of the scanner's internal state.
|
|
// See also `Scanner.state()`.
|
|
pub struct State {
|
|
pub:
|
|
col int // current column number (x coordinate)
|
|
line_nr int = 1 // current line number (y coordinate)
|
|
pos int // current flat/index position in the `text` field
|
|
}
|
|
|
|
// Config is used to configure a Scanner instance.
|
|
// Only one of the fields `text` and `file_path` is allowed to be set at time of configuration.
|
|
pub struct Config {
|
|
pub:
|
|
input input.Config
|
|
tokenize_formatting bool = true // if true, generate tokens for `\n`, ` `, `\t`, `\r` etc.
|
|
}
|
|
|
|
// new_scanner returns a new *heap* allocated `Scanner` instance, based on the file in config.input.file_path,
|
|
// or based on the text in config.input.text .
|
|
pub fn new_scanner(config Config) ?&Scanner {
|
|
mut s := &Scanner{
|
|
config: config
|
|
text: config.input.read_input()?
|
|
}
|
|
return s
|
|
}
|
|
|
|
// new_simple returns a new *stack* allocated `Scanner` instance.
|
|
pub fn new_simple(config Config) ?Scanner {
|
|
return Scanner{
|
|
config: config
|
|
text: config.input.read_input()?
|
|
}
|
|
}
|
|
|
|
// new_simple_text returns a new *stack* allocated `Scanner` instance
|
|
// ready for parsing TOML in `text`.
|
|
pub fn new_simple_text(text string) ?Scanner {
|
|
in_config := input.Config{
|
|
text: text
|
|
}
|
|
config := Config{
|
|
input: in_config
|
|
}
|
|
return Scanner{
|
|
config: config
|
|
text: config.input.read_input()?
|
|
}
|
|
}
|
|
|
|
// new_simple_file returns a new *stack* allocated `Scanner` instance
|
|
// ready for parsing TOML in file read from `path`.
|
|
pub fn new_simple_file(path string) ?Scanner {
|
|
in_config := input.Config{
|
|
file_path: path
|
|
}
|
|
config := Config{
|
|
input: in_config
|
|
}
|
|
return Scanner{
|
|
config: config
|
|
text: config.input.read_input()?
|
|
}
|
|
}
|
|
|
|
// scan returns the next token from the input.
|
|
[direct_array_access]
|
|
pub fn (mut s Scanner) scan() ?token.Token {
|
|
s.validate_and_skip_headers()?
|
|
|
|
for {
|
|
c := s.next()
|
|
byte_c := u8(c)
|
|
if c == scanner.end_of_text {
|
|
s.inc_line_number()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'reached EOF')
|
|
return s.new_token(.eof, '', 1)
|
|
}
|
|
|
|
ascii := byte_c.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'current char "$ascii"')
|
|
|
|
if byte_c == u8(0x0) {
|
|
s.reset()
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' NULL control character `$c.hex()` is not allowed at ($s.line_nr,$s.col) "$ascii" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
|
|
is_sign := c == `+` || c == `-`
|
|
|
|
// (+/-)nan & (+/-)inf
|
|
peek_1 := s.peek(1)
|
|
peek_2 := s.peek(2)
|
|
is_nan := c == `n` && s.at() == `a` && peek_1 == `n`
|
|
is_inf := !is_nan && c == `i` && s.at() == `n` && peek_1 == `f`
|
|
is_signed_nan := is_sign && s.at() == `n` && peek_1 == `a` && peek_2 == `n`
|
|
is_signed_inf := !is_signed_nan && is_sign && s.at() == `i` && peek_1 == `n`
|
|
&& peek_2 == `f`
|
|
if !s.is_left_of_assign && (is_nan || is_inf || is_signed_nan || is_signed_inf) {
|
|
num := s.extract_nan_or_inf_number()?
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified a special number "$num" ($num.len)')
|
|
return s.new_token(.number, num, num.len)
|
|
}
|
|
|
|
is_signed_number := is_sign && u8(s.at()).is_digit() && !u8(s.peek(-1)).is_digit()
|
|
is_digit := byte_c.is_digit()
|
|
if is_digit || is_signed_number {
|
|
num := s.extract_number()?
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified a number "$num" ($num.len)')
|
|
return s.new_token(.number, num, num.len)
|
|
}
|
|
|
|
if util.is_key_char(byte_c) {
|
|
key := s.extract_key()
|
|
if !s.is_left_of_assign && (key == 'true' || key == 'false') {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified a boolean "$key" ($key.len)')
|
|
return s.new_token(.boolean, key, key.len)
|
|
}
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified a bare key "$key" ($key.len)')
|
|
return s.new_token(.bare, key, key.len)
|
|
}
|
|
|
|
match rune(c) {
|
|
` `, `\t`, `\n`, `\r` {
|
|
if c == `\n` {
|
|
s.inc_line_number()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'incremented line nr to $s.line_nr')
|
|
}
|
|
// Date-Time in RFC 3339 is allowed to have a space between the date and time in supplement to the 'T'
|
|
// so we allow space characters to slip through to the parser if the space is between two digits...
|
|
// util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, '"'+u8(s.peek(-1)).ascii_str()+'" < "$ascii" > "'+u8(s.at()).ascii_str()+'"')
|
|
if c == ` ` && u8(s.peek(-1)).is_digit() && u8(s.at()).is_digit() {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified, what could be, a space between a RFC 3339 date and time ("$ascii") ($ascii.len)')
|
|
return s.new_token(token.Kind.whitespace, ascii, ascii.len)
|
|
}
|
|
if s.config.tokenize_formatting {
|
|
mut kind := token.Kind.whitespace
|
|
if c == `\t` {
|
|
kind = token.Kind.tab
|
|
} else if c == `\r` {
|
|
kind = token.Kind.cr
|
|
} else if c == `\n` {
|
|
kind = token.Kind.nl
|
|
}
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified formatting character ("$ascii") ($ascii.len)')
|
|
return s.new_token(kind, ascii, ascii.len)
|
|
} else {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'skipping " ", "\\t" or "\\n" ("$ascii") ($ascii.len)')
|
|
}
|
|
continue
|
|
}
|
|
`-` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified minus "$ascii" ($ascii.len)')
|
|
return s.new_token(.minus, ascii, ascii.len)
|
|
}
|
|
`_` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified underscore "$ascii" ($ascii.len)')
|
|
return s.new_token(.underscore, ascii, ascii.len)
|
|
}
|
|
`+` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified plus "$ascii" ($ascii.len)')
|
|
return s.new_token(.plus, ascii, ascii.len)
|
|
}
|
|
`=` {
|
|
s.is_left_of_assign = false
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified assignment "$ascii" ($ascii.len)')
|
|
return s.new_token(.assign, ascii, ascii.len)
|
|
}
|
|
`"`, `'` { // ... some string "/'
|
|
ident_string := s.extract_string()?
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified quoted string `$ident_string`')
|
|
return s.new_token(.quoted, ident_string, ident_string.len)
|
|
}
|
|
`#` {
|
|
hash := s.ignore_line()?
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified comment hash "$hash" ($hash.len)')
|
|
return s.new_token(.hash, hash, hash.len + 1)
|
|
}
|
|
`{` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified left curly bracket "$ascii" ($ascii.len)')
|
|
return s.new_token(.lcbr, ascii, ascii.len)
|
|
}
|
|
`}` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified right curly bracket "$ascii" ($ascii.len)')
|
|
return s.new_token(.rcbr, ascii, ascii.len)
|
|
}
|
|
`[` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified left square bracket "$ascii" ($ascii.len)')
|
|
return s.new_token(.lsbr, ascii, ascii.len)
|
|
}
|
|
`]` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified right square bracket "$ascii" ($ascii.len)')
|
|
return s.new_token(.rsbr, ascii, ascii.len)
|
|
}
|
|
`:` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified colon "$ascii" ($ascii.len)')
|
|
return s.new_token(.colon, ascii, ascii.len)
|
|
}
|
|
`,` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified comma "$ascii" ($ascii.len)')
|
|
return s.new_token(.comma, ascii, ascii.len)
|
|
}
|
|
`.` {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified period "$ascii" ($ascii.len)')
|
|
return s.new_token(.period, ascii, ascii.len)
|
|
}
|
|
else {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' could not scan character `$ascii` / $c at $s.pos ($s.line_nr,$s.col) near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
}
|
|
}
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'unknown character code at $s.pos ($s.line_nr,$s.col) near ...${s.excerpt(s.pos,
|
|
5)}...')
|
|
return s.new_token(.unknown, '', 0)
|
|
}
|
|
|
|
// free frees all allocated resources.
|
|
[unsafe]
|
|
pub fn (mut s Scanner) free() {
|
|
unsafe {
|
|
s.text.free()
|
|
}
|
|
}
|
|
|
|
// remaining returns how many characters remain in the text input.
|
|
[inline]
|
|
pub fn (s &Scanner) remaining() int {
|
|
return s.text.len - s.pos
|
|
}
|
|
|
|
// next returns the next character code from the input text.
|
|
// next returns `end_of_text` if it can't reach the next character.
|
|
[direct_array_access; inline]
|
|
pub fn (mut s Scanner) next() u32 {
|
|
if s.pos < s.text.len {
|
|
opos := s.pos
|
|
s.pos++
|
|
s.col++
|
|
c := s.text[opos]
|
|
return c
|
|
}
|
|
return scanner.end_of_text
|
|
}
|
|
|
|
// skip skips one character ahead.
|
|
[inline]
|
|
pub fn (mut s Scanner) skip() {
|
|
if s.pos + 1 < s.text.len {
|
|
s.pos++
|
|
s.col++
|
|
}
|
|
}
|
|
|
|
// skip_n skips ahead `n` characters.
|
|
// If the skip goes out of bounds from the length of `Scanner.text`,
|
|
// the scanner position will be sat to the last character possible.
|
|
[inline]
|
|
pub fn (mut s Scanner) skip_n(n int) {
|
|
s.pos += n
|
|
if s.pos > s.text.len {
|
|
s.pos = s.text.len
|
|
}
|
|
s.col = s.pos
|
|
}
|
|
|
|
// at returns the *current* character code from the input text.
|
|
// at returns `end_of_text` if it can't get the current character.
|
|
// unlike `next()`, `at()` does not change the state of the scanner.
|
|
[direct_array_access; inline]
|
|
pub fn (s &Scanner) at() u32 {
|
|
if s.pos < s.text.len {
|
|
return s.text[s.pos]
|
|
}
|
|
return scanner.end_of_text
|
|
}
|
|
|
|
// at_crlf returns `true` if the scanner is at a `\r` character
|
|
// and the next character is a `\n`.
|
|
fn (s Scanner) at_crlf() bool {
|
|
return s.at() == `\r` && s.peek(1) == `\n`
|
|
}
|
|
|
|
// peek returns the character code from the input text at position + `n`.
|
|
// peek returns `end_of_text` if it can't peek `n` characters ahead.
|
|
[direct_array_access; inline]
|
|
pub fn (s &Scanner) peek(n int) u32 {
|
|
if s.pos + n < s.text.len {
|
|
// Allow peeking back - needed for spaces between date and time in RFC 3339 format :/
|
|
if n - 1 < 0 && s.pos + n - 1 >= 0 {
|
|
// util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'LOOKING BAAAA-AACK - OOOVER MY SHOOOOULDEEEER "${s.text[s.pos + n-1]}"')
|
|
return s.text[s.pos + n - 1]
|
|
}
|
|
return s.text[s.pos + n]
|
|
}
|
|
return scanner.end_of_text
|
|
}
|
|
|
|
// reset resets the internal state of the scanner.
|
|
pub fn (mut s Scanner) reset() {
|
|
s.pos = 0
|
|
s.col = 0
|
|
s.line_nr = 1
|
|
s.header_len = 0
|
|
}
|
|
|
|
// new_token returns a new `token.Token`.
|
|
[inline]
|
|
fn (mut s Scanner) new_token(kind token.Kind, lit string, len int) token.Token {
|
|
// println('new_token($lit)')
|
|
mut col := s.col - len + 1
|
|
if s.line_nr == 1 {
|
|
col -= s.header_len
|
|
}
|
|
return token.Token{
|
|
kind: kind
|
|
lit: lit
|
|
col: if col < 1 { 1 } else { col }
|
|
line_nr: s.line_nr + 1
|
|
pos: s.pos - s.header_len - len + 1
|
|
len: len
|
|
}
|
|
}
|
|
|
|
// ignore_line forwards the scanner to the end of the current line.
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) ignore_line() ?string {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, ' ignoring until EOL...')
|
|
start := s.pos
|
|
for c := s.at(); c != scanner.end_of_text && c != `\n`; c = s.at() {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'skipping "${u8(c).ascii_str()} / $c"')
|
|
if s.at_crlf() {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'letting `\\r\\n` slip through')
|
|
break
|
|
}
|
|
s.next()
|
|
}
|
|
return s.text[start..s.pos]
|
|
}
|
|
|
|
// inc_line_number increases the internal line number.
|
|
[inline]
|
|
fn (mut s Scanner) inc_line_number() {
|
|
s.col = 0
|
|
s.line_nr++
|
|
s.is_left_of_assign = true
|
|
}
|
|
|
|
// extract_key parses and returns a TOML key as a string.
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) extract_key() string {
|
|
s.pos--
|
|
s.col--
|
|
start := s.pos
|
|
for s.pos < s.text.len {
|
|
c := u8(s.at())
|
|
if !(util.is_key_char(c) || c.is_digit() || c in [`_`, `-`]) {
|
|
break
|
|
}
|
|
s.pos++
|
|
s.col++
|
|
}
|
|
key := s.text[start..s.pos]
|
|
return key
|
|
}
|
|
|
|
// extract_string collects and returns a string containing
|
|
// any bytes recognized as a TOML string.
|
|
// TOML strings are everything found between two double or single quotation marks (`"`/`'`).
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) extract_string() ?string {
|
|
// extract_string is called when the scanner has already reached
|
|
// a byte that is the start of a string so we rewind it to start at the correct
|
|
s.pos--
|
|
s.col--
|
|
quote := u8(s.at())
|
|
start := s.pos
|
|
mut lit := quote.ascii_str()
|
|
|
|
is_multiline := s.text[s.pos + 1] == quote && s.text[s.pos + 2] == quote
|
|
// Check for escaped multiline quote
|
|
if is_multiline {
|
|
mls := s.extract_multiline_string()?
|
|
return mls
|
|
}
|
|
|
|
for {
|
|
s.pos++
|
|
s.col++
|
|
|
|
if s.pos >= s.text.len {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' unfinished single-line string literal `$quote.ascii_str()` started at $start ($s.line_nr,$s.col) "${u8(s.at()).ascii_str()}" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
|
|
c := u8(s.at())
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'c: `$c.ascii_str()` / $c (quote type: $quote/$quote.ascii_str())')
|
|
|
|
// Check for escaped chars
|
|
if c == u8(92) {
|
|
esc, skip := s.handle_escapes(quote, is_multiline)
|
|
lit += esc
|
|
if skip > 0 {
|
|
s.pos += skip
|
|
s.col += skip
|
|
continue
|
|
}
|
|
}
|
|
// Check for control characters (allow TAB)
|
|
if util.is_illegal_ascii_control_character(c) {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' control character `$c.hex()` is not allowed at $start ($s.line_nr,$s.col) "${u8(s.at()).ascii_str()}" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
|
|
if c == quote {
|
|
s.pos++
|
|
s.col++
|
|
return lit + quote.ascii_str()
|
|
}
|
|
|
|
lit += c.ascii_str()
|
|
|
|
// Don't eat multiple lines in single-line mode
|
|
if lit.contains('\n') {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' unfinished single-line string literal `$quote.ascii_str()` started at $start ($s.line_nr,$s.col) "${u8(s.at()).ascii_str()}" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
}
|
|
return lit
|
|
}
|
|
|
|
// extract_multiline_string collects and returns a string containing
|
|
// any bytes recognized as a TOML string.
|
|
// TOML strings are everything found between two double or single quotation marks (`"`/`'`).
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) extract_multiline_string() ?string {
|
|
// extract_multiline_string is called from extract_string so we know the 3 first
|
|
// characters is the quotes
|
|
quote := u8(s.at())
|
|
start := s.pos
|
|
mut lit := quote.ascii_str() + quote.ascii_str() + quote.ascii_str()
|
|
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'multi-line `$quote.ascii_str()${s.text[s.pos +
|
|
1].ascii_str()}${s.text[s.pos + 2].ascii_str()}` string started at pos $start ($s.line_nr,$s.col) (quote type: $quote.ascii_str() / $quote)')
|
|
|
|
s.pos += 2
|
|
s.col += 2
|
|
|
|
for {
|
|
s.pos++
|
|
s.col++
|
|
|
|
if s.pos >= s.text.len {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' unfinished multi-line string literal ($quote.ascii_str()$quote.ascii_str()$quote.ascii_str()) started at $start ($s.line_nr,$s.col) "${u8(s.at()).ascii_str()}" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
|
|
c := u8(s.at())
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'c: `$c.ascii_str()` / $c (quote type: $quote/$quote.ascii_str())')
|
|
|
|
if c == `\n` {
|
|
s.inc_line_number()
|
|
lit += c.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'c: `\\n` / $c')
|
|
continue
|
|
}
|
|
// Check for escaped chars
|
|
if c == u8(92) {
|
|
esc, skip := s.handle_escapes(quote, true)
|
|
lit += esc
|
|
if skip > 0 {
|
|
s.pos += skip
|
|
s.col += skip
|
|
continue
|
|
}
|
|
}
|
|
// Check for control characters (allow TAB)
|
|
if util.is_illegal_ascii_control_character(c) {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' control character `$c.hex()` is not allowed at $start ($s.line_nr,$s.col) "${u8(s.at()).ascii_str()}" near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
|
|
if c == quote {
|
|
if s.peek(1) == quote && s.peek(2) == quote {
|
|
if s.peek(3) == scanner.end_of_text {
|
|
s.pos += 3
|
|
s.col += 3
|
|
lit += quote.ascii_str() + quote.ascii_str() + quote.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'returning at $c.ascii_str() `$lit`')
|
|
return lit
|
|
} else if s.peek(3) != quote {
|
|
// lit += c.ascii_str()
|
|
// lit += quote.ascii_str()
|
|
s.pos += 3
|
|
s.col += 3
|
|
lit += quote.ascii_str() + quote.ascii_str() + quote.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'returning at $c.ascii_str() `$lit`')
|
|
return lit
|
|
}
|
|
}
|
|
}
|
|
lit += c.ascii_str()
|
|
}
|
|
return lit
|
|
}
|
|
|
|
// handle_escapes returns any escape character sequence.
|
|
// For escape sequence validation see `Checker.check_quoted_escapes`.
|
|
fn (mut s Scanner) handle_escapes(quote u8, is_multiline bool) (string, int) {
|
|
c := u8(s.at())
|
|
mut lit := c.ascii_str()
|
|
is_literal_string := quote == `'`
|
|
if !is_literal_string {
|
|
if s.peek(1) == `u` && u8(s.peek(2)).is_hex_digit() && u8(s.peek(3)).is_hex_digit()
|
|
&& u8(s.peek(4)).is_hex_digit() && u8(s.peek(5)).is_hex_digit() {
|
|
lit += s.text[s.pos + 1..s.pos + 6] //.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'gulp escaped unicode `$lit`')
|
|
return lit, 5
|
|
} else if s.peek(1) == quote {
|
|
if (!is_multiline && s.peek(2) == `\n`)
|
|
|| (is_multiline && s.peek(2) == quote && s.peek(3) == quote && s.peek(4) == `\n`) {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'ignore special case escaped `$lit` at end of string')
|
|
return '', 0
|
|
}
|
|
lit += quote.ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'gulp escaped `$lit`')
|
|
return lit, 1
|
|
}
|
|
}
|
|
if is_literal_string {
|
|
if s.peek(1) == quote {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'ignore escape `$lit${u8(s.peek(1)).ascii_str()}` in literal string')
|
|
return '', 0
|
|
}
|
|
}
|
|
|
|
lit += u8(s.peek(1)).ascii_str()
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'gulp escaped `$lit`')
|
|
return lit, 1
|
|
}
|
|
|
|
// extract_number collects and returns a string containing
|
|
// any bytes recognized as a TOML number except for "(+/-)nan" and "(+/-)inf".
|
|
// TOML numbers can include digits 0-9 and `_`.
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) extract_number() ?string {
|
|
// extract_number is called when the scanner has already reached
|
|
// a byte that is a number or +/- - so we rewind it to start at the correct
|
|
// position to get the complete number. Even if it's only one digit
|
|
s.pos--
|
|
s.col--
|
|
start := s.pos
|
|
|
|
mut c := s.at()
|
|
is_digit := u8(c).is_digit()
|
|
if !(is_digit || c in [`+`, `-`]) {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' ${u8(c).ascii_str()} is not a number at ${s.excerpt(s.pos, 10)}')
|
|
}
|
|
s.pos++
|
|
s.col++
|
|
for s.pos < s.text.len {
|
|
c = s.at()
|
|
// Handle signed exponent notation. I.e.: 3e2, 3E2, 3e-2, 3E+2, 3e0, 3.1e2, 3.1E2, -1E-1
|
|
if c in [`e`, `E`] && s.peek(1) in [`+`, `-`] && u8(s.peek(2)).is_digit() {
|
|
s.pos += 2
|
|
s.col += 2
|
|
}
|
|
c = s.at()
|
|
if !(u8(c).is_hex_digit() || c in scanner.digit_extras) || (c == `.` && s.is_left_of_assign) {
|
|
break
|
|
}
|
|
s.pos++
|
|
s.col++
|
|
}
|
|
key := s.text[start..s.pos]
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified number "$key" in range [$start .. $s.pos]')
|
|
return key
|
|
}
|
|
|
|
// extract_nan_or_inf_number collects and returns a string containing
|
|
// any bytes recognized as infinity or not-a-number TOML numbers.
|
|
[direct_array_access; inline]
|
|
fn (mut s Scanner) extract_nan_or_inf_number() ?string {
|
|
// extract_nan_or_inf_number is called when the scanner has already identified that
|
|
// +/- or 'nan'/'inf' bytes is up but we rewind it to start at the correct position
|
|
s.pos--
|
|
s.col--
|
|
start := s.pos
|
|
|
|
mut c := s.at()
|
|
if c !in [`+`, `-`, `n`, `i`] {
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' ${u8(c).ascii_str()} is not a number at ${s.excerpt(s.pos, 10)}')
|
|
}
|
|
s.pos++
|
|
s.col++
|
|
for s.pos < s.text.len {
|
|
c = s.at()
|
|
if c !in [`n`, `a`, `i`, `f`] {
|
|
break
|
|
}
|
|
s.pos++
|
|
s.col++
|
|
}
|
|
key := s.text[start..s.pos]
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'identified special number "$key" in range [$start .. $s.pos]')
|
|
return key
|
|
}
|
|
|
|
// excerpt returns a string excerpt of the input text centered
|
|
// at `pos`. The `margin` argument defines how many chacters
|
|
// on each side of `pos` is returned
|
|
pub fn (s Scanner) excerpt(pos int, margin int) string {
|
|
start := if pos > 0 && pos >= margin { pos - margin } else { 0 }
|
|
end := if pos + margin < s.text.len { pos + margin } else { s.text.len }
|
|
return s.text[start..end].replace('\n', r'\n')
|
|
}
|
|
|
|
// state returns a read-only view of the scanner's internal state.
|
|
pub fn (s Scanner) state() State {
|
|
return State{
|
|
col: s.col
|
|
line_nr: s.line_nr
|
|
pos: s.pos
|
|
}
|
|
}
|
|
|
|
fn (mut s Scanner) validate_and_skip_headers() ? {
|
|
// UTF-16 / UTF-32 headers (BE/LE)
|
|
s.check_utf16_or_32_bom()?
|
|
|
|
// NICE-TO-HAVE-TODO Check other types of (UTF-?) headers and yield an error. TOML is UTF-8 only.
|
|
|
|
// Skip optional UTF-8 heaser, if any.
|
|
if s.at() == 0xEF && s.peek(1) == 0xBB && s.peek(2) == 0xBF {
|
|
util.printdbg(@MOD + '.' + @STRUCT + '.' + @FN, 'skipping UTF-8 byte order mark (BOM)')
|
|
s.header_len = 3
|
|
s.skip_n(s.header_len)
|
|
}
|
|
|
|
// Check after we've skipped UTF-8 BOM
|
|
s.check_utf16_or_32_bom()?
|
|
}
|
|
|
|
fn (mut s Scanner) check_utf16_or_32_bom() ? {
|
|
if (s.at() == 0xFF && s.peek(1) == 0xFE && s.peek(2) == 0x00 && s.peek(3) == 0x00)
|
|
|| (s.at() == 0x00 && s.peek(1) == 0x00 && s.peek(2) == 0xFE && s.peek(3) == 0xFF) {
|
|
s.header_len = 4
|
|
s.skip_n(s.header_len)
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' UTF-32 is not a valid TOML encoding at $s.pos ($s.line_nr,$s.col) near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
if (s.at() == 0xFE && s.peek(1) == 0xFF) || (s.at() == 0xFF && s.peek(1) == 0xFE) {
|
|
s.header_len = 2
|
|
s.skip_n(s.header_len)
|
|
return error(@MOD + '.' + @STRUCT + '.' + @FN +
|
|
' UTF-16 is not a valid TOML encoding at $s.pos ($s.line_nr,$s.col) near ...${s.excerpt(s.pos, 5)}...')
|
|
}
|
|
}
|