strings.textscanner #

fn new #

fn new(input string) TextScanner

new returns a stack allocated instance of TextScanner.

struct TextScanner #

struct TextScanner {
pub:
	input string
	ilen  int
mut:
	pos int
}

TextScanner simplifies writing small scanners/parsers by providing safe methods to scan texts character by character, peek for the next characters, go back, etc.

fn (TextScanner) free #

unsafe
fn (mut ss TextScanner) free()

free frees all allocated resources.

fn (TextScanner) remaining #

fn (ss &TextScanner) remaining() int

remaining returns how many characters remain from current position.

fn (TextScanner) next #

fn (mut ss TextScanner) next() int

next returns the next character code from the input text.
next returns -1 if it can't reach the next character.
next advances the scanner position.

fn (TextScanner) skip #

fn (mut ss TextScanner) skip()

skip skips one character ahead; skip() is slightly faster than .next().
skip() does not return a result.

fn (TextScanner) skip_n #

fn (mut ss TextScanner) skip_n(n int)

skip_n skips ahead n characters, stopping at the end of the input.

fn (TextScanner) peek #

fn (ss &TextScanner) peek() int

peek returns the next character code from the input text.
peek returns -1 if it can't peek the next character.
unlike next(), peek() does not change the state of the scanner.

fn (TextScanner) peek_n #

fn (ss &TextScanner) peek_n(n int) int

peek_n returns the character code from the input text at position + n.
peek_n returns -1 if it can't peek n characters ahead.
ts.peek_n(0) == ts.current() .
ts.peek_n(1) == ts.peek() .

fn (TextScanner) back #

fn (mut ss TextScanner) back()

back goes back one character from the current scanner position.

fn (TextScanner) back_n #

fn (mut ss TextScanner) back_n(n int)

back_n goes back n characters from the current scanner position.

fn (TextScanner) peek_back #

fn (ss &TextScanner) peek_back() int

peek_back returns the previous character code from the input text.
peek_back returns -1 if it can't peek the previous character.
unlike back(), peek_back() does not change the state of the scanner.

fn (TextScanner) peek_back_n #

fn (ss &TextScanner) peek_back_n(n int) int

peek_back_n returns the character code from the input text at position - n.
peek_back_n returns -1 if it can't peek n characters back.
ts.peek_back_n(0) == ts.current() ts.peek_back_n(1) == ts.peek_back()

fn (TextScanner) current #

fn (mut ss TextScanner) current() int

current returns the current character code from the input text.
current returns -1 at the start of the input text.
NB: after c := ts.next(), ts.current() will also return c.

fn (TextScanner) reset #

fn (mut ss TextScanner) reset()

reset resets the internal state of the scanner After calling .reset(), .next() will start reading again from the start of the input text.

fn (TextScanner) goto_end #

fn (mut ss TextScanner) goto_end()

goto_end has the same effect as for ts.next() != -1 {} i.e. after calling .goto_end(), the scanner will be at the end of the input text. Further .next() calls will return -1, unless you go back.