Types

ParseState = ref object stream: Stream position, lastPosition: ParsePosition: A ParseState keeps track of the Stream and where we are at it. Source Edit
ParseResult[T] = Result[T, ParseError]: A ParseResult of type T is a Result object with either a parsed object of type T or a ParseError. Source Edit
Parser[T] = ParseState -> ParseResult[T]: A Parser for a type T is a function that receives a ParseState and gives back a ParseResult of type T. Source Edit

Procs

proc `$`[T](res: ParseResult[T]): string {...}{.inline.}

Represent a ParseResult as a string. Mostly used to print errors. Source Edit

proc peekChar(state: ParseState): char {...}{.inline, raises: [IOError, OSError], tags: [ReadIOEffect].}

Peeks a char from the ParseState state. Raises IOError if an error occurred. Returns '0' as an EOF marker. Source Edit

proc readLastStr(state: ParseState; length: int): string {...}{.inline, raises: [IOError, OSError], tags: [ReadIOEffect].}

Reads a string of length length from the ParseState state ending at the current position. Raises IOError if an error occurred. Source Edit

proc readStr(state: ParseState; length: int): string {...}{.inline, raises: [IOError, OSError], tags: [ReadIOEffect].}

Reads a string of length length from the ParseState state starting at the current position. Raises IOError if an error occurred.

Note: This function is experimental.

proc debugParse[T](parser: Parser[T]; x: auto; withPosition = false): string {...}{. inline.}

func fail[T](unexpected: string; expected: openArray[string]; state: ParseState; message = ""): ParseResult[T] {...}{.inline.}: Stop parsing and report a ParseError. Source Edit
func fail[T](res: ParseResult[auto]): ParseResult[T] {...}{.inline.}: Stop parsing and report the ParseError of a ParseResult. Source Edit
func newParseState(s: Stream): ParseState {...}{.inline, raises: [], tags: [].}: Creates a new ParseState from the stream s. Source Edit

template atEnd(state: ParseState): bool: Checks if more data can be read from state. Returns true if all data has been read. Source Edit
template stepBack(state: ParseState): Go a step back. Source Edit
template getPosition(state: ParseState): int: Retrieves the current position in the ParseState state. Source Edit
template readChar(state: ParseState): char: Reads a char from the ParseState state. Raises IOError if an error occurred. Returns '0' as an EOF marker. Source Edit
template newParseState(s: string): ParseState: Creates a new ParseState from the string s. Source Edit
template parse[T; ](parser: Parser[T]; x: auto): ParseResult[T]: Apply a Parser to x. Source Edit
template parse[T](parser: Parser[T]; x: ParseState): ParseResult[T]: Apply a Parser to x. Source Edit