Specialty Parsers

In addition to the Core Parsers, ParserObjects provides a few pre-built parsers for common and familiar programming tasks. Several of these methods will cache the created instances so you don’t recreate them on every call. Exceptions will be noted below. All of the specialty parsers assume char input, because all of these tasks are related to characters and strings.

Digit Parsers

ParserObjects provides parsers for parsing digits (‘0’-‘9’) and sequences of digits.

using static ParserObjects.Parsers.Specialty.DigitParserMethods;

A Single Digit

The Digit parser returns a single character in the range ('0'-'9'). The NonZeroDigit parser returns a single character in the range ('1'-'9'), and the HexadecimalDigit parser returns any valid hex character ('a'-'z', 'A'-'Z', '0'-'9').

var parser = Digit();
var parser = NonZeroDigit();
var parser = HexadecimalDigit();

A String of Digits

The DigitString parser returns a string of consecutive digits. The HexadecimalString parser returns a string of hexadecimal digits.

var parser = DigitString();
var parser = HexadecimalString();

Line Parsers

using static ParserObjects.Parsers.Specialty.LineParserMethods

The Line method parses the remainder of the line until the next newline ('\n') character. It does not return the newline character. The PrefixedLine method parses the line if it starts with the given prefix. If the prefix is null or empty, it is the same as Line.

var parser = Line();
var parser = PrefixedLine("abc");

The PrefixedLine parser is not cached.

Whitespace Parsers

using static ParserObjects.Parsers.Specialty.WhitespaceParserMethods;

The WhitespaceCharacter parser matches any single whitespace character and returns it. The Whitespace parser returns a string of one or more whitespace characters and returns the string. The OptionalWhitespace parser returns a string of zero or more whitespace characters.

var parser = WhitespaceCharacter();
var parser = Whitespace();
var parser = OptionalWhitespace();

Quoted String Parsers

using static ParserObjects.Parsers.Specialty.QuotedParserMethods;

ParserObjects provides several methods for parsing quoted strings with escape characters. By default, the backslash ('\') is used as an escape character, which is a common idiom in modern programming and data serialization languages. These methods all have two variants, one to return the literal match including quotes and escape sequences, and a “stripped” version to return the string contents without quotes or escapes.

Double Quoted Strings

var parser = DoubleQuotedString();
var parser = StrippedDoubleQuotedString();

Single Quoted Strings

var parser = SingleQuotedString();
var parser = StrippedSingleQuotedString();

Custom Strings

You can create your own string parser method by specifying the start, stop and escape characters:

var parser = DelimitedStringWithEscapedDelimiters('"', '"', '\\');
var parser = StrippedDelimitedStringWithEscapedDelimiters('"', '"', '\\');

The parsers created by these methods are not cached.

Regexes

You can use basic regular expressions to create a parser:

using static ParserObjects.Parsers.Specialty.RegexParserMethods;

var parser = Regex("(a|b)?c*");

For more details on what syntax is supported by the Regex parser, see the Regexes Page. Be warned that certain types of patterns may create pathological backtracking behavior which will hurt the performance of your parser.