Package io.github.classgraph.utils

Class Parser

java.lang.Object

io.github.classgraph.utils.Parser

public class Parser
extends Object

A generic PEG parser.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Parser.ParseException	A parsing exception.

Constructor Summary

Constructors

Constructor	Description
Parser(String string)	Construct a parser.

Method Summary

Modifier and Type	Method	Description
void	advance(int numChars)	Advance numChars character positions.
void	appendToToken(char c)	Append the given character to the token buffer.
void	appendToToken(String str)	Append the given string to the token buffer.
String	currToken()	Get the current token, and reset the token to empty.
void	expect(char expectedChar)	Expect the next character.
char	getc()	Get the next character.
int	getPosition()
String	getPositionInfo()
Object	getState()	Get the "state object" from the parser (can be used to parse state between parser functions).
CharSequence	getSubsequence(int startPosition, int endPosition)	Return a subsequence of the input string.
String	getSubstring(int startPosition, int endPosition)	Return a substring of the input string.
boolean	hasMore()
void	next()	Advance one character without returning the value of the character.
char	peek()
void	peekExpect(char expectedChar)	Get the next character, throwing a Parser.ParseException if the next character is not the expected character.
boolean	peekMatches(String strMatch)	Peek operator that can look ahead several characters.
void	setPosition(int position)	Set the position of the parser within the string.
Object	setState(Object state)	Set the "state object" from the parser (can be used to parse state between parser functions).
void	skipWhitespace()	Skip whitespace starting at the current position.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Parser

public Parser(String string)
       throws Parser.ParseException

Construct a parser.

Parameters:

string - The string to parse.

Throws:

Parser.ParseException - If the string was null.

Method Detail

getPositionInfo

public String getPositionInfo()

Returns:

A string showing parsing context, for debugging.

setState

public Object setState(Object state)

Set the "state object" from the parser (can be used to parse state between parser functions).

Parameters:

state - The state object.

Returns:

The old value of the state object.

getState

public Object getState()

Get the "state object" from the parser (can be used to parse state between parser functions).

Returns:

The current value of the state object.

getc

public char getc()
          throws Parser.ParseException

Get the next character.

Returns:

The next character.

Throws:

Parser.ParseException - If there were no more characters in the string.

expect

public void expect(char expectedChar)
            throws Parser.ParseException

Expect the next character.

Parameters:

expectedChar - The expected character.

Throws:

Parser.ParseException - If the next character was not the expected character.

peek

public char peek()

Returns:

The next character, or '\0' if at the end of the string.

peekExpect

public void peekExpect(char expectedChar)
                throws Parser.ParseException

Get the next character, throwing a Parser.ParseException if the next character is not the expected character.

Parameters:

expectedChar - The expected next character.

Throws:

Parser.ParseException - If the next character is not the expected next character.

peekMatches

public boolean peekMatches(String strMatch)

Peek operator that can look ahead several characters.

Parameters:

strMatch - The string to compare, starting at the current position, as a "peek" operation.

Returns:

True if the strMatch matches a substring of the remaining string starting at the current position.

next

public void next()

Advance one character without returning the value of the character.

advance

public void advance(int numChars)

Advance numChars character positions.

Parameters:

numChars - The number of character positions to advance.

Throws:

IllegalArgumentException - If there are insufficient characters remaining in the string.

hasMore

public boolean hasMore()

Returns:

true if the input has not all been consumed.

getPosition

public int getPosition()

Returns:

the current position.

setPosition

public void setPosition(int position)

Set the position of the parser within the string.

Parameters:

position - The position to move to.

Throws:

IllegalArgumentException - If the position is out of range.

getSubsequence

public CharSequence getSubsequence(int startPosition,
                                   int endPosition)

Return a subsequence of the input string.

Parameters:

startPosition - The start position.

endPosition - The end position.

Returns:

The subsequence.

getSubstring

public String getSubstring(int startPosition,
                           int endPosition)

Return a substring of the input string.

Parameters:

startPosition - The start position.

endPosition - The end position.

Returns:

The substring.

appendToToken

public void appendToToken(String str)

Append the given string to the token buffer.

Parameters:

str - The string to append.

appendToToken

public void appendToToken(char c)

Append the given character to the token buffer.

Parameters:

c - The character to append.

skipWhitespace

public void skipWhitespace()

Skip whitespace starting at the current position.

currToken

public String currToken()

Get the current token, and reset the token to empty.

Returns:

The current token. Resets the current token to empty.

toString

public String toString()

Overrides:

toString in class Object