Loyc.Syntax.Lexing.LexerSource< CharSrc > Class Template Reference

An implementation of the LLLPG Lexer API, used with the LLLPG options inputSource and inputClass. More...

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Source file:

• /Core/Loyc.Syntax/Lexing/LexerSource.cs

Inheritance diagram for Loyc.Syntax.Lexing.LexerSource< CharSrc >:

Remarks

An implementation of the LLLPG Lexer API, used with the LLLPG options inputSource and inputClass.

This derived class simply makes public all of the LLLPG APIs which are marked protected in BaseLexer{CharSrc}.

LLLPG(lexer(inputSource(src), inputClass(LexerSource))) { static rule int ParseInt(string input) { var src = (LexerSource<UString>)input; @[ (d:='0'..'9' {$result = $result * 10 + (d - '0');})+ ]; } }

Template Parameters

CharSrc

A class that implements ICharSource. In order to write lexers that can accept any source of characters, set CharSrc=ICharSource. For maximum performance when parsing strings (or to avoid memory allocation), set CharSrc=UString (UString is a wrapper around System.String that, among other things, implements ICharSource; please note that C# will implicitly convert normal strings to UString for you).

Type Constraints

CharSrc

:

ICharSource

Properties
new int	LA0 [get]
new CharSrc	CharSource [get]
new string	FileName [get]
new int	InputPosition [get, set]
new LexerSourceFile< CharSrc >	SourceFile [get]
new int	LineStartAt [get]
Properties inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
IMessageSink	ErrorSink [get, set]
	Gets or sets the object to which error messages are sent. The default object is FormatExceptionErrorSink, which throws FormatException if an error occurs. More...
int	LA0 [get, set]
CharSrc	CharSource [get]
string	FileName [get]
int	InputPosition [get, set]
LexerSourceFile< CharSrc >	SourceFile [get]
int	LineNumber [get]
	Current line number. Starts at 1 for the first line, unless derived class changes it. More...
int	LineStartAt [get]
	Index at which the current line started. More...
Properties inherited from Loyc.Syntax.Lexing.ILllpgApi< Token, MatchType, LaType >
LaType	LA0 [get]

Public Member Functions
	LexerSource (CharSrc source, string fileName="", int inputPosition=0, bool newSourceFile=true)
	Initializes LexerSource. More...
virtual new void	Reset (CharSrc source, string fileName="", int inputPosition=0, bool newSourceFile=true)
	Reinitializes the object. This method is called by the constructor.See the constructor for documentation of the parameters. This method can be used to avoid memory allocations when you need to parse many small strings in a row. If that's your goal, you should set the newSourceFile parameter to false if possible.
new void	Reset ()
new int	LA (int i)
new void	Skip ()
virtual new void	AfterNewline ()
	The lexer must call this method exactly once after it advances past each newline, even inside comments and strings. This method keeps the LineNumber and LineStartAt properties updated.
new void	Newline ()
new int	MatchAny ()
new int	Match (HashSet< int > set)
new int	Match (int a)
new int	Match (int a, int b)
new int	Match (int a, int b, int c)
new int	Match (int a, int b, int c, int d)
new int	MatchRange (int aLo, int aHi)
new int	MatchRange (int aLo, int aHi, int bLo, int bHi)
new int	MatchExcept ()
new int	MatchExcept (HashSet< int > set)
new int	MatchExcept (int a)
new int	MatchExcept (int a, int b)
new int	MatchExcept (int a, int b, int c)
new int	MatchExcept (int a, int b, int c, int d)
new int	MatchExceptRange (int aLo, int aHi)
new int	MatchExceptRange (int aLo, int aHi, int bLo, int bHi)
new bool	TryMatch (HashSet< int > set)
new bool	TryMatch (int a)
new bool	TryMatch (int a, int b)
new bool	TryMatch (int a, int b, int c)
new bool	TryMatch (int a, int b, int c, int d)
new bool	TryMatchRange (int aLo, int aHi)
new bool	TryMatchRange (int aLo, int aHi, int bLo, int bHi)
new bool	TryMatchExcept ()
new bool	TryMatchExcept (HashSet< int > set)
new bool	TryMatchExcept (int a)
new bool	TryMatchExcept (int a, int b)
new bool	TryMatchExcept (int a, int b, int c)
new bool	TryMatchExcept (int a, int b, int c, int d)
new bool	TryMatchExceptRange (int aLo, int aHi)
new bool	TryMatchExceptRange (int aLo, int aHi, int bLo, int bHi)
virtual new void	Check (bool expectation, string expectedDescr="")
virtual new void	Error (int lookaheadIndex, string format)
	This method is called to handle errors that occur during lexing. More...
virtual new void	Error (int lookaheadIndex, string format, params object[] args)
	This method is called to format and handle errors that occur during lexing. The default implementation sends errors to ErrorSink, which, by default, throws a FormatException. More...
new void	PrintChar (int c, StringBuilder sb)
Public Member Functions inherited from Loyc.Syntax.Lexing.LexerSourceWorkaround< CharSrc >
	LexerSourceWorkaround (CharSrc source, string fileName="", int inputPosition=0, bool newSourceFile=true)
Public Member Functions inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
	BaseLexer (CharSrc chars, string fileName="", int inputPosition=0, bool newSourceFile=true)
	Initializes BaseLexer. More...
SourcePos	IndexToLine (int index)
	Returns the position in a source file of the specified index. More...
Public Member Functions inherited from Loyc.Syntax.Lexing.ILllpgApi< Token, MatchType, LaType >
Token	Match (MatchType a)
Token	Match (MatchType a, MatchType b)
Token	Match (MatchType a, MatchType b, MatchType c)
Token	Match (MatchType a, MatchType b, MatchType c, MatchType d)
Token	Match (HashSet< MatchType > set)
Token	MatchExcept (MatchType a)
Token	MatchExcept (MatchType a, MatchType b)
Token	MatchExcept (MatchType a, MatchType b, MatchType c)
Token	MatchExcept (MatchType a, MatchType b, MatchType c, MatchType d)
Token	MatchExcept (HashSet< MatchType > set)
bool	TryMatch (MatchType a)
bool	TryMatch (MatchType a, MatchType b)
bool	TryMatch (MatchType a, MatchType b, MatchType c)
bool	TryMatch (MatchType a, MatchType b, MatchType c, MatchType d)
bool	TryMatch (HashSet< MatchType > set)
bool	TryMatchExcept (MatchType a)
bool	TryMatchExcept (MatchType a, MatchType b)
bool	TryMatchExcept (MatchType a, MatchType b, MatchType c)
bool	TryMatchExcept (MatchType a, MatchType b, MatchType c, MatchType d)
bool	TryMatchExcept (HashSet< MatchType > set)

Static Public Member Functions
static new HashSet< int >	NewSet (params int[] items)
static new HashSet< int >	NewSetOfRanges (params int[] ranges)
static	operator LexerSource< CharSrc > (CharSrc str)

Protected Member Functions
override void	Error_Renamed (int lookaheadIndex, string format, params object[] args)
override void	Error_Renamed (int lookaheadIndex, string format)
Protected Member Functions inherited from Loyc.Syntax.Lexing.LexerSourceWorkaround< CharSrc >
override void	Error (int lookaheadIndex, string format)
	This method is called to handle errors that occur during lexing. More...
override void	Error (int lookaheadIndex, string format, params object[] args)
	This method is called to format and handle errors that occur during lexing. The default implementation sends errors to ErrorSink, which, by default, throws a FormatException. More...
Protected Member Functions inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
void	Reset ()
int	LA (int i)
void	Skip ()
	Increments InputPosition. Called by LLLPG when prediction already verified the input (and caller doesn't save LA(0)) More...
void	Newline ()
	Default newline parser that matches ' ' or '' unconditionally. More...
void	Spaces ()
	Skips past any spaces at the current position. Equivalent to rule Spaces @[ (' '|'')* ] in LLLPG. More...
int	MatchAny ()
int	Match (HashSet< int > set)
int	Match (int a)
int	Match (int a, int b)
int	Match (int a, int b, int c)
int	Match (int a, int b, int c, int d)
int	MatchRange (int aLo, int aHi)
int	MatchRange (int aLo, int aHi, int bLo, int bHi)
int	MatchExcept ()
int	MatchExcept (HashSet< int > set)
int	MatchExcept (int a)
int	MatchExcept (int a, int b)
int	MatchExcept (int a, int b, int c)
int	MatchExcept (int a, int b, int c, int d)
int	MatchExceptRange (int aLo, int aHi)
int	MatchExceptRange (int aLo, int aHi, int bLo, int bHi)
bool	TryMatch (HashSet< int > set)
bool	TryMatch (int a)
bool	TryMatch (int a, int b)
bool	TryMatch (int a, int b, int c)
bool	TryMatch (int a, int b, int c, int d)
bool	TryMatchRange (int aLo, int aHi)
bool	TryMatchRange (int aLo, int aHi, int bLo, int bHi)
bool	TryMatchExcept ()
bool	TryMatchExcept (HashSet< int > set)
bool	TryMatchExcept (int a)
bool	TryMatchExcept (int a, int b)
bool	TryMatchExcept (int a, int b, int c)
bool	TryMatchExcept (int a, int b, int c, int d)
bool	TryMatchExceptRange (int aLo, int aHi)
bool	TryMatchExceptRange (int aLo, int aHi, int bLo, int bHi)
virtual void	Error (bool inverted, int range0lo, int range0hi)
virtual void	Error (bool inverted, params int[] ranges)
virtual void	Error (bool inverted, IList< int > ranges)
virtual void	Error (bool inverted, HashSet< int > set)
string	RangesToString (IList< int > ranges)
	Converts a list of character ranges to a string, e.g. for input list {'*','*','a','z'}, the output is "'*' 'a'..'z'". More...
void	PrintChar (int c, StringBuilder sb)
	Prints a character as a string, e.g. 'a' -> "'a'", with the special value -1 representing EOF, so PrintChar(-1, ...) == "EOF". More...

Additional Inherited Members
Public static fields inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
static readonly IMessageSink	FormatExceptionErrorSink
	Throws FormatException when it receives an error. Non-errors are sent to MessageSink.Current. More...
Static Protected Member Functions inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
static HashSet< int >	NewSet (params int[] items)
static HashSet< int >	NewSetOfRanges (params int[] ranges)
Protected fields inherited from Loyc.Syntax.Lexing.BaseLexer< CharSrc >
int	CachedBlockSize = 128
int	_lineStartAt
int	_lineNumber = 1

Constructor & Destructor Documentation

Loyc.Syntax.Lexing.LexerSource< CharSrc >.LexerSource ( CharSrc  source, string  fileName = "", int  inputPosition = 0, bool  newSourceFile = true  )

inline

Initializes LexerSource.

Parameters

source	A source of characters, e.g. UString.
fileName	A file name associated with the characters, which will be used for error reporting.
inputPosition	A location to start lexing (normally 0). Careful: If you're starting to lex in the middle of the file, the BaseLexer{C}.LineNumber still starts at 1, and (if newSourceFile is true) the SourceFile object may or may not discover line breaks prior to the starting point, depending on how it is used.
newSourceFile	Whether to create a LexerSourceFile{C} object (an implementation of ISourceFile) to keep track of line boundaries. The SourceFile property will point to this object, and it will be null if this parameter is false. Using 'false' will avoid memory allocation, but prevent you from mapping character positions to line numbers and vice versa. However, this object will still keep track of the current BaseLexer{C}.LineNumber and LineStartAt (the index where the current line started) when this parameter is false.

Member Function Documentation

virtual new void Loyc.Syntax.Lexing.LexerSource< CharSrc >.Error ( int  lookaheadIndex, string  message  )

inlinevirtual

This method is called to handle errors that occur during lexing.

Parameters

lookaheadIndex	Index where the error occurred, relative to the current InputPosition (i.e. InputPosition + lookaheadIndex is the position of the error).
message	An error message, not including the error location.

Reimplemented from Loyc.Syntax.Lexing.BaseLexer< CharSrc >.

virtual new void Loyc.Syntax.Lexing.LexerSource< CharSrc >.Error ( int  lookaheadIndex, string  format, params object[]  args  )

inlinevirtual

This method is called to format and handle errors that occur during lexing. The default implementation sends errors to ErrorSink, which, by default, throws a FormatException.

Parameters

lookaheadIndex	Index where the error occurred, relative to the current InputPosition (i.e. InputPosition + lookaheadIndex is the position of the error).
format	An error description with argument placeholders.
args	Arguments to insert into the error message.

Reimplemented from Loyc.Syntax.Lexing.BaseLexer< CharSrc >.