me.jaimegarza.syntax.model.parser

Class ErrorToken

java.lang.Object

me.jaimegarza.syntax.model.parser.Symbol

me.jaimegarza.syntax.model.parser.Terminal

me.jaimegarza.syntax.model.parser.ErrorToken

public class ErrorToken
extends Terminal

~pojo class

Represents an error non terminal in the grammar . Error tokens are defined with %error. They are used by the grammar to generate an error recovery table. When an error is found during the resulting code's parsing phase, the recover table is used to try to recover the engine to a valid state where compilation could continue so that the parsing does not stop at the first error.

The error recovery system is based on an algorithm that drops stack states until one with a proper error token transition is found.

Other than that, error tokens are just another non-terminal symbol.

Symbols have the following hierarchy:

  -+ Symbol
   |
   +--+ Terminal     - Lexical Symbol (i.e. number, id '+')
   |  |
   |  +-- ErrorToken - Lexical Symbol declared with %error
   |
   +-- NonTerminal   - Syntactical symbol (i.e. Expression, Statement)
   

Author:

jaimegarza@gmail.com

Field Summary

Fields inherited from class me.jaimegarza.syntax.model.parser.Symbol

associativity, count, fullName, id, name, precedence, token, type, variable

Constructor Summary

Constructors

Constructor and Description
ErrorToken(String name)

Method Summary

Methods inherited from class me.jaimegarza.syntax.model.parser.Symbol

computeVariable, equals, getAssociativity, getCount, getFullName, getId, getName, getPrecedence, getToken, getType, getVariable, isIdentifier, setAssociativity, setCount, setFullName, setId, setName, setPrecedence, setToken, setType, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ErrorToken

public ErrorToken(String name)