io.parsingdata.metal.token

Class Pre

java.lang.Object

io.parsingdata.metal.token.Token

io.parsingdata.metal.token.Pre

public class Pre
extends Token

A Token that specifies a precondition for parsing a nested token.

A Pre consists of a token (a Token) and a predicate (an Expression). First predicate is evaluated. If it evaluates to true, the token is parsed. Parsing this token will only succeed if the predicate evaluates to true and if parsing the nested token succeeds.

See Also:

Expression

Field Summary

Fields

Modifier and Type	Field and Description
Expression	predicate
Token	token

Fields inherited from class io.parsingdata.metal.token.Token

EMPTY_NAME, encoding, name, NO_NAME, SEPARATOR

Constructor Summary

Constructors

Constructor and Description
Pre(String name, Token token, Expression predicate, Encoding encoding)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
int	hashCode()
protected Optional<ParseState>	parseImpl(Environment environment)
String	toString()

Methods inherited from class io.parsingdata.metal.token.Token

getCanonical, isLocal, makeNameFragment, parse

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

token

public final Token token

predicate

public final Expression predicate

Constructor Detail

Pre

public Pre(String name,
           Token token,
           Expression predicate,
           Encoding encoding)

Method Detail

parseImpl

protected Optional<ParseState> parseImpl(Environment environment)

Specified by:

parseImpl in class Token

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Token

hashCode

public int hashCode()

Overrides:

hashCode in class Token