Class Parser<TToken, T>

Represents a parser which consumes a stream of values of type TToken and returns a value of type T. A parser can either succeed, and return a value of type T, or fail and return a ParseError<TToken>.

Inheritance

Object
Parser<TToken, T>

Declaration

public abstract class Parser<TToken, T> : Object

Type Parameters

Name	Description
TToken	The type of the tokens in the parser's input stream
T	The type of the value returned by the parser

Remarks

This type is not intended to be subclassed by users of the library

Constructors

Parser()

Declaration

protected Parser()

Methods

Assert(Func<T, Boolean>)

Creates a parser that fails if the value returned by the current parser fails to satisfy a predicate.

Declaration

public Parser<TToken, T> Assert(Func<T, bool> predicate)

Parameters

Type	Name	Description
Func<T, Boolean>	predicate	The predicate to apply to the value returned by the current parser

Returns

Type	Description
Parser<TToken, T>	A parser that fails if the value returned by the current parser fails to satisfy `predicate`

Assert(Func<T, Boolean>, Func<T, String>)

Creates a parser that fails if the value returned by the current parser fails to satisfy a predicate.

Declaration

public Parser<TToken, T> Assert(Func<T, bool> predicate, Func<T, string> message)

Parameters

Type	Name	Description
Func<T, Boolean>	predicate	The predicate to apply to the value returned by the current parser
Func<T, String>	message	A function to produce a custom error message to return when the value returned by the current parser fails to satisfy the predicate

Returns

Type	Description
Parser<TToken, T>	A parser that fails if the value returned by the current parser fails to satisfy `predicate`

Assert(Func<T, Boolean>, String)

Creates a parser that fails if the value returned by the current parser fails to satisfy a predicate.

Declaration

public Parser<TToken, T> Assert(Func<T, bool> predicate, string message)

Parameters

Type	Name	Description
Func<T, Boolean>	predicate	The predicate to apply to the value returned by the current parser
String	message	A custom error message to return when the value returned by the current parser fails to satisfy the predicate

Returns

Type	Description
Parser<TToken, T>	A parser that fails if the value returned by the current parser fails to satisfy `predicate`

AtLeastOnce()

Creates a parser that applies the current parser one or more times. The resulting parser fails if the current parser fails the first time it is applied, or if the current parser fails after consuming input

Declaration

public Parser<TToken, IEnumerable<T>> AtLeastOnce()

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser that applies the current parser one or more times

AtLeastOnceUntil(Parser<TToken, U>)

Creates a parser which applies this parser one or more times until terminator succeeds. Fails if this parser fails or if terminator fails after consuming input. The return value of terminator is ignored.

Declaration

public Parser<TToken, IEnumerable<T>> AtLeastOnceUntil<U>(Parser<TToken, U> terminator)

Parameters

Type	Name	Description
Parser<TToken, U>	terminator	A parser to parse a terminator

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies this parser repeatedly until `terminator` succeeds

Type Parameters

Name	Description
U

Before(Parser<TToken, U>)

Creates a parser that applies the current parser followed by the specified parser. The resulting parser returns the result of the current parser, ignoring the result of the second parser.

Declaration

public Parser<TToken, T> Before<U>(Parser<TToken, U> parser)

Parameters

Type	Name	Description
Parser<TToken, U>	parser	The parser to apply after applying the current parser.

Returns

Type	Description
Parser<TToken, T>	A parser that applies the current parser followed by the specified parser

Type Parameters

Name	Description
U	The type of the value returned by the second parser

Between(Parser<TToken, U>)

Creates a parser that applies the specified parser both before and after applying the current parser. The resulting parser returns the result of the current parser, ignoring the return value of the bracketing parser.

Declaration

public Parser<TToken, T> Between<U>(Parser<TToken, U> parser)

Parameters

Type	Name	Description
Parser<TToken, U>	parser	The parser to apply before and after applying the current parser

Returns

Type	Description
Parser<TToken, T>	A parser that applies the specified parser before and after applying the current parser

Type Parameters

Name	Description
U	The type of the value returned by the bracketing parser

Between<U, V>(Parser<TToken, U>, Parser<TToken, V>)

Creates a parser that applies the specified parsers before and after applying the current parser. The resulting parser returns the result of the current parser, ignoring the return values of the bracketing parsers.

Declaration

public Parser<TToken, T> Between<U, V>(Parser<TToken, U> parser1, Parser<TToken, V> parser2)

Parameters

Type	Name	Description
Parser<TToken, U>	parser1	The parser to apply before applying the current parser
Parser<TToken, V>	parser2	The parser to apply after applying the current parser

Returns

Type	Description
Parser<TToken, T>	A parser that applies the specified parsers before and after applying the current parser

Type Parameters

Name	Description
U	The type of the value returned by the first parser
V	The type of the value returned by the second parser

Bind(Func<T, Parser<TToken, U>>)

Creates a parser that applies a transformation function to the return value of the current parser. The transformation function dynamically chooses a second parser, which is applied after applying the current parser.

Declaration

public Parser<TToken, U> Bind<U>(Func<T, Parser<TToken, U>> selector)

Parameters

Type	Name	Description
Func<T, Parser<TToken, U>>	selector	A transformation function which returns a parser to apply after applying the current parser

Returns

Type	Description
Parser<TToken, U>	A parser which applies the current parser before applying the result of the `selector` function.

Type Parameters

Name	Description
U	The type of the return value of the second parser

Bind<U, R>(Func<T, Parser<TToken, U>>, Func<T, U, R>)

Declaration

public Parser<TToken, R> Bind<U, R>(Func<T, Parser<TToken, U>> selector, Func<T, U, R> result)

Parameters

Type	Name	Description
Func<T, Parser<TToken, U>>	selector	A transformation function which returns a parser to apply after applying the current parser
Func<T, U, R>	result	A function to apply to the return values of the two parsers

Returns

Type	Description
Parser<TToken, R>	A parser which applies the current parser before applying the result of the `selector` function

Type Parameters

Name	Description
U	The type of the return value of the second parser
R	The type of the return value of the resulting parser

Cast()

Cast the return value of the current parser to the specified result type

Declaration

public Parser<TToken, U> Cast<U>()

Returns

Type	Description
Parser<TToken, U>	A parser which returns this parser's return value casted to `U`

Type Parameters

Name	Description
U	The type to cast the return value to

Exceptions

Type	Condition
InvalidCastException	Thrown when the return value is not an instance of `U`

IgnoreResult()

Creates a parser which behaves like the current parser but returns Value. Equivalent to p.WithResult(Unit.Value).

Declaration

public Parser<TToken, Unit> IgnoreResult()

Returns

Type	Description
Parser<TToken, Unit>	A parser which behaves like the current parser but returns Value.

Labelled(String)

Creates a parser equivalent to the current parser, with a custom label. The label will be reported in an error message if the parser fails, instead of the default error message. Expected Label

Declaration

public Parser<TToken, T> Labelled(string label)

Parameters

Type	Name	Description
String	label	The custom label to apply to the current parser

Returns

Type	Description
Parser<TToken, T>	A parser equivalent to the current parser, with a custom label

Many()

Creates a parser which applies the current parser zero or more times. The resulting parser fails if the current parser fails after consuming input.

Declaration

public Parser<TToken, IEnumerable<T>> Many()

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser zero or more times

Map(Func<T, U>)

Creates a parser which applies the specified transformation function to the result of the current parser. This is an infix synonym for Map<TToken, T1, R>(Func<T1, R>, Parser<TToken, T1>).

Declaration

public Parser<TToken, U> Map<U>(Func<T, U> selector)

Parameters

Type	Name	Description
Func<T, U>	selector	A transformation function

Returns

Type	Description
Parser<TToken, U>	A parser which applies `selector` to the result of the current parser

Type Parameters

Name	Description
U	The return type of the transformation function

MapWithInput(ReadOnlySpanFunc<TToken, T, U>)

Returns a parser which runs the current parser and applies a selector function. The selector function receives a ReadOnlySpan<T> as its first argument, and the result of the current parser as its second argument. The ReadOnlySpan<T> represents the sequence of input tokens which were consumed by the parser.

This allows you to write "pattern"-style parsers which match a sequence of tokens and return a view of the part of the input stream which they matched.

This function is an alternative name for Slice(ReadOnlySpanFunc<TToken, T, U>).

Declaration

public Parser<TToken, U> MapWithInput<U>(ReadOnlySpanFunc<TToken, T, U> selector)

Parameters

Type	Name	Description
ReadOnlySpanFunc<TToken, T, U>	selector	A selector function which computes a result of type `U`. The arguments of the selector function are a ReadOnlySpan<T> containing the sequence of input tokens which were consumed by this parser, and the result of this parser.

Returns

Type	Description
Parser<TToken, U>	A parser which runs the current parser and applies a selector function.

Type Parameters

Name	Description
U	The result type

OfType()

Creates a parser which casts the return value of the current parser to the specified result type, or fails if the return value is not an instance of U.

Declaration

public Parser<TToken, U> OfType<U>()

Returns

Type	Description
Parser<TToken, U>	A parser which returns the current parser's return value casted to `U`, if the value is an instance of `U`

Type Parameters

Name	Description
U	The type to cast the return value of the current parser to

Optional()

Creates a parser which applies the current parser and returns Nothing<T>() if the current parser fails without consuming any input. The resulting parser fails if the current parser fails after consuming input.

Declaration

public Parser<TToken, Maybe<T>> Optional()

Returns

Type	Description
Parser<TToken, Maybe<T>>	A parser which applies the current parser and returns Nothing<T>() if the current parser fails without consuming any input

Or(Parser<TToken, T>)

Creates a parser which tries to apply the current parser, applying the specified parser if the current parser fails without consuming any input. The resulting parser fails if both the current parser and the alternative parser fail, or if the current parser fails after consuming input.

Declaration

public Parser<TToken, T> Or(Parser<TToken, T> parser)

Parameters

Type	Name	Description
Parser<TToken, T>	parser	The alternative parser to apply if the current parser fails without consuming any input

Returns

Type	Description
Parser<TToken, T>	A parser which tries to apply the current parser, and applies `parser` if the current parser fails without consuming any input.

RecoverWith(Func<ParseError<TToken>, Parser<TToken, T>>)

Creates a parser which runs the current parser, running errorHandler on failure.

Declaration

public Parser<TToken, T> RecoverWith(Func<ParseError<TToken>, Parser<TToken, T>> errorHandler)

Parameters

Type	Name	Description
Func<ParseError<TToken>, Parser<TToken, T>>	errorHandler	A function which returns a parser to apply when the current parser fails.

Returns

Type	Description
Parser<TToken, T>	A parser which runs the current parser, running `errorHandler` on failure.

Repeat(Int32)

Creates a parser which applies the current parser count times.

Declaration

public Parser<TToken, IEnumerable<T>> Repeat(int count)

Parameters

Type	Name	Description
Int32	count	The number of times to apply the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser `count` times.

Exceptions

Type	Condition
InvalidOperationException	`count` is less than 0

Select(Func<T, U>)

Creates a parser which applies the specified transformation function to the result of the current parser. This is an infix synonym for Map<TToken, T1, R>(Func<T1, R>, Parser<TToken, T1>).

Declaration

public Parser<TToken, U> Select<U>(Func<T, U> selector)

Parameters

Type	Name	Description
Func<T, U>	selector	A transformation function

Returns

Type	Description
Parser<TToken, U>	A parser which applies `selector` to the result of the current parser

Type Parameters

Name	Description
U	The return type of the transformation function

SelectMany<U, R>(Func<T, Parser<TToken, U>>, Func<T, U, R>)

Declaration

public Parser<TToken, R> SelectMany<U, R>(Func<T, Parser<TToken, U>> selector, Func<T, U, R> result)

Parameters

Type	Name	Description
Func<T, Parser<TToken, U>>	selector	A transformation function which returns a parser to apply after applying the current parser
Func<T, U, R>	result	A function to apply to the return values of the two parsers

Returns

Type	Description
Parser<TToken, R>	A parser which applies the current parser before applying the result of the `selector` function

Type Parameters

Name	Description
U	The type of the return value of the second parser
R	The type of the return value of the resulting parser

Separated(Parser<TToken, U>)

Creates a parser which applies the current parser repeatedly, interleaved with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> Separated<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser repeatedly, interleaved by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SeparatedAndOptionallyTerminated(Parser<TToken, U>)

Creates a parser which applies the current parser repeatedly, interleaved and optionally terminated with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> SeparatedAndOptionallyTerminated<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser repeatedly, interleaved and optionally terminated by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SeparatedAndOptionallyTerminatedAtLeastOnce(Parser<TToken, U>)

Creates a parser which applies the current parser at least once, interleaved and optionally terminated with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> SeparatedAndOptionallyTerminatedAtLeastOnce<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser at least once, interleaved and optionally terminated by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SeparatedAndTerminated(Parser<TToken, U>)

Creates a parser which applies the current parser repeatedly, interleaved and terminated with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> SeparatedAndTerminated<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser repeatedly, interleaved and terminated by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SeparatedAndTerminatedAtLeastOnce(Parser<TToken, U>)

Creates a parser which applies the current parser at least once, interleaved and terminated with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> SeparatedAndTerminatedAtLeastOnce<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser at least once, interleaved and terminated by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SeparatedAtLeastOnce(Parser<TToken, U>)

Creates a parser which applies the current parser at least once, interleaved with a specified parser. The resulting parser ignores the return value of the separator parser.

Declaration

public Parser<TToken, IEnumerable<T>> SeparatedAtLeastOnce<U>(Parser<TToken, U> separator)

Parameters

Type	Name	Description
Parser<TToken, U>	separator	A parser which parses a separator to be interleaved with the current parser

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies the current parser at least once, interleaved by `separator`

Type Parameters

Name	Description
U	The return type of the separator parser

SkipAtLeastOnce()

Creates a parser that applies the current parser one or more times, discarding the results. This is more efficient than AtLeastOnce(), if you don't need the results. The resulting parser fails if the current parser fails the first time it is applied, or if the current parser fails after consuming input

Declaration

public Parser<TToken, Unit> SkipAtLeastOnce()

Returns

Type	Description
Parser<TToken, Unit>	A parser that applies the current parser one or more times, discarding the results

SkipAtLeastOnceUntil(Parser<TToken, U>)

Creates a parser which applies this parser one or more times until terminator succeeds, discarding the results. This is more efficient than AtLeastOnceUntil(Parser<TToken, U>) if you don't need the results. Fails if this parser fails or if terminator fails after consuming input. The return value of terminator is ignored.

Declaration

public Parser<TToken, Unit> SkipAtLeastOnceUntil<U>(Parser<TToken, U> terminator)

Parameters

Type	Name	Description
Parser<TToken, U>	terminator	A parser to parse a terminator

Returns

Type	Description
Parser<TToken, Unit>	A parser which applies this parser repeatedly until `terminator` succeeds, discarding the results

Type Parameters

Name	Description
U

SkipMany()

Creates a parser which applies the current parser zero or more times, discarding the results. This is more efficient than Many(), if you don't need the results. The resulting parser fails if the current parser fails after consuming input.

Declaration

public Parser<TToken, Unit> SkipMany()

Returns

Type	Description
Parser<TToken, Unit>	A parser which applies the current parser zero or more times

SkipUntil(Parser<TToken, U>)

Creates a parser which applies this parser zero or more times until terminator succeeds, discarding the results. This is more efficient than Until(Parser<TToken, U>) if you don't need the results. Fails if this parser fails or if terminator fails after consuming input. The return value of terminator is ignored.

Declaration

public Parser<TToken, Unit> SkipUntil<U>(Parser<TToken, U> terminator)

Parameters

Type	Name	Description
Parser<TToken, U>	terminator	A parser to parse a terminator

Returns

Type	Description
Parser<TToken, Unit>	A parser which applies this parser repeatedly until `terminator` succeeds, discarding the results

Type Parameters

Name	Description
U	The return type of `terminator`

Slice(ReadOnlySpanFunc<TToken, T, U>)

This allows you to write "pattern"-style parsers which match a sequence of tokens and return a view of the part of the input stream which they matched.

This function is an alternative name for MapWithInput(ReadOnlySpanFunc<TToken, T, U>).

Declaration

public Parser<TToken, U> Slice<U>(ReadOnlySpanFunc<TToken, T, U> selector)

Parameters

Type	Name	Description
ReadOnlySpanFunc<TToken, T, U>	selector	A selector function which computes a result of type `U`. The arguments of the selector function are a ReadOnlySpan<T> containing the sequence of input tokens which were consumed by this parser, and the result of this parser.

Returns

Type	Description
Parser<TToken, U>	A parser which runs the current parser and applies a selector function.

Type Parameters

Name	Description
U	The result type

Then(Parser<TToken, U>)

Creates a parser which applies the current parser followed by a specified parser. The resulting parser returns the result of the second parser, ignoring the result of the current parser.

Declaration

public Parser<TToken, U> Then<U>(Parser<TToken, U> parser)

Parameters

Type	Name	Description
Parser<TToken, U>	parser	A parser to apply after applying the current parser

Returns

Type	Description
Parser<TToken, U>	A parser which applies the current parser followed by `parser`

Type Parameters

Name	Description
U	The return type of the second parser

Then(Func<T, Parser<TToken, U>>)

Declaration

public Parser<TToken, U> Then<U>(Func<T, Parser<TToken, U>> selector)

Parameters

Type	Name	Description
Func<T, Parser<TToken, U>>	selector	A transformation function which returns a parser to apply after applying the current parser

Returns

Type	Description
Parser<TToken, U>	A parser which applies the current parser before applying the result of the `selector` function.

Type Parameters

Name	Description
U	The type of the return value of the second parser

Remarks

This function is a synonym for Bind(Func<T, Parser<TToken, U>>)

Then<U, R>(Parser<TToken, U>, Func<T, U, R>)

Creates a parser which applies the current parser followed by a specified parser, applying a function to the two results.

Declaration

public Parser<TToken, R> Then<U, R>(Parser<TToken, U> parser, Func<T, U, R> result)

Parameters

Type	Name	Description
Parser<TToken, U>	parser	A parser to apply after applying the current parser
Func<T, U, R>	result	A function to apply to the two parsed values

Returns

Type	Description
Parser<TToken, R>	A parser which applies the current parser followed by `parser`

Type Parameters

Name	Description
U	The return type of the second parser
R	The return type of the composed parser

Remarks

This is a synonym for Map<TToken, T1, T2, R>(Func<T1, T2, R>, Parser<TToken, T1>, Parser<TToken, T2>) with the arguments rearranged.

Then<U, R>(Func<T, Parser<TToken, U>>, Func<T, U, R>)

Declaration

public Parser<TToken, R> Then<U, R>(Func<T, Parser<TToken, U>> selector, Func<T, U, R> result)

Parameters

Type	Name	Description
Func<T, Parser<TToken, U>>	selector	A transformation function which returns a parser to apply after applying the current parser
Func<T, U, R>	result	A function to apply to the return values of the two parsers

Returns

Type	Description
Parser<TToken, R>	A parser which applies the current parser before applying the result of the `selector` function

Type Parameters

Name	Description
U	The type of the return value of the second parser
R	The type of the return value of the resulting parser

Remarks

This function is a synonym for Bind<U, R>(Func<T, Parser<TToken, U>>, Func<T, U, R>)

ThenReturn(U)

Creates a parser which behaves like the current parser but returns result after a successful parse. This is a synonym for WithResult(U).

Declaration

public Parser<TToken, U> ThenReturn<U>(U result)

Parameters

Type	Name	Description
U	result	The result

Returns

Type	Description
Parser<TToken, U>	A parser which behaves like the current parser but returns `result`.

Type Parameters

Name	Description
U

Examples

Equivalent to using Select(Func<T, U>) with a function that returns a fixed value, or Then(Parser<TToken, U>) with Return<T>(T).

p.ThenReturn(x) == p.Select(_ => x) == p.Then(Return(x));

Trace(Func<T, String>)

For debugging use.

Creates a new parser which runs the current parser and prints the given message to the console.

Declaration

public Parser<TToken, T> Trace(Func<T, string> message)

Parameters

Type	Name	Description
Func<T, String>	message

Returns

Type	Description
Parser<TToken, T>	A parser which runs the current parser and prints the given message to the console.

Trace(String)

For debugging use.

Creates a new parser which runs the current parser and prints the given message to the console.

Declaration

public Parser<TToken, T> Trace(string message)

Parameters

Type	Name	Description
String	message

Returns

Type	Description
Parser<TToken, T>	A parser which runs the current parser and prints the given message to the console.

TraceResult()

For debugging use.

Creates a new parser which runs the current parser and prints the result to the console.

Declaration

public Parser<TToken, T> TraceResult()

Returns

Type	Description
Parser<TToken, T>	A parser which runs the current parser and prints the result to the console.

TryParse(ref ParseState<TToken>, ref PooledList<Expected<TToken>>, out T)

Override this method to implement a custom parser. Use this if you can't do what you need using the base parser combinators.

If your parser fails it should return false and call SetError(Maybe<TToken>, Boolean, Int32, String).

WARNING: This API is unstable and subject to change in future versions of the library.

Declaration

public abstract bool TryParse(ref ParseState<TToken> state, ref PooledList<Expected<TToken>> expecteds, out T result)

Parameters

Type	Name	Description
ParseState<TToken>	state	The parser's state.
PooledList<Expected<TToken>>	expecteds	A list to which the parser can add its expected tokens when it fails
T	result	The result

Returns

Type	Description
Boolean	True if the parser succeeded, false if it failed.

Until(Parser<TToken, U>)

Creates a parser which applies this parser zero or more times until terminator succeeds. Fails if this parser fails or if terminator fails after consuming input. The return value of terminator is ignored.

Declaration

public Parser<TToken, IEnumerable<T>> Until<U>(Parser<TToken, U> terminator)

Parameters

Type	Name	Description
Parser<TToken, U>	terminator	A parser to parse a terminator

Returns

Type	Description
Parser<TToken, IEnumerable<T>>	A parser which applies this parser repeatedly until `terminator` succeeds

Type Parameters

Name	Description
U	The return type of `terminator`

Where(Func<T, Boolean>)

Creates a parser that fails if the value returned by the current parser fails to satisfy a predicate.

Declaration

public Parser<TToken, T> Where(Func<T, bool> predicate)

Parameters

Type	Name	Description
Func<T, Boolean>	predicate	The predicate to apply to the value returned by the current parser

Returns

Type	Description
Parser<TToken, T>	A parser that fails if the value returned by the current parser fails to satisfy `predicate`

Remarks

This function is a synonym of Assert(Func<T, Boolean>)

WithResult(U)

Creates a parser which behaves like the current parser but returns result after a successful parse. This is a synonym for ThenReturn(U).

Declaration

public Parser<TToken, U> WithResult<U>(U result)

Parameters

Type	Name	Description
U	result	The result

Returns

Type	Description
Parser<TToken, U>	A parser which behaves like the current parser but returns `result`.

Type Parameters

Name	Description
U

Examples

Equivalent to using Select(Func<T, U>) with a function that returns a fixed value, or Then(Parser<TToken, U>) with Return<T>(T).

p.WithResult(x) == p.Select(_ => x) == p.Then(Return(x));

Extension Methods

ParserExtensions.Parse<TToken, T>(Parser<TToken, T>, IList<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseReadOnlyList<TToken, T>(Parser<TToken, T>, IReadOnlyList<TToken>, IConfiguration<TToken>)

ParserExtensions.Parse<TToken, T>(Parser<TToken, T>, IEnumerable<TToken>, IConfiguration<TToken>)

ParserExtensions.Parse<TToken, T>(Parser<TToken, T>, IEnumerator<TToken>, IConfiguration<TToken>)

ParserExtensions.Parse<TToken, T>(Parser<TToken, T>, TToken[], IConfiguration<TToken>)

ParserExtensions.Parse<TToken, T>(Parser<TToken, T>, ReadOnlySpan<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseOrThrow<TToken, T>(Parser<TToken, T>, IList<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseReadOnlyListOrThrow<TToken, T>(Parser<TToken, T>, IReadOnlyList<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseOrThrow<TToken, T>(Parser<TToken, T>, IEnumerable<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseOrThrow<TToken, T>(Parser<TToken, T>, IEnumerator<TToken>, IConfiguration<TToken>)

ParserExtensions.ParseOrThrow<TToken, T>(Parser<TToken, T>, TToken[], IConfiguration<TToken>)

ParserExtensions.ParseOrThrow<TToken, T>(Parser<TToken, T>, ReadOnlySpan<TToken>, IConfiguration<TToken>)