com.singularsys.jep.misc.lineNumbering
Class LineNumberingShuntingYard

java.lang.Object
  com.singularsys.jep.configurableparser.ShuntingYard
      com.singularsys.jep.misc.lineNumbering.LineNumberingShuntingYard

All Implemented Interfaces:

GrammarParser

public class LineNumberingShuntingYard
extends ShuntingYard

Version of the shunting yard algorithm which sets lines numbers in the parse tree. By convention numbering starts from line 1 column 1.

Since:

3.4.0

Author:

rich

Nested Class Summary

static class

LineNumberingShuntingYard.LineNumberGrammarParserFactory

Nested classes/interfaces inherited from class com.singularsys.jep.configurableparser.ShuntingYard

ShuntingYard.ShuntingYardGrammarParserFactory

Field Summary

protected java.util.Stack<com.singularsys.jep.misc.lineNumbering.LineNumberingShuntingYard.Position>

posns Stack to track positions when pushing and popping operators

Fields inherited from class com.singularsys.jep.configurableparser.ShuntingYard

DUMP, implicitMul, it, jep, matchers, nf, nodes, ops, sentinel

Constructor Summary

LineNumberingShuntingYard(Jep jep, java.util.List<GrammarMatcher> gm)
Constructor

Method Summary

Node	parseSubExpression() Callback function used by GrammerMatchers
protected void	popOp() Pops an operator off the Operator stack, and creates a new node.
protected void	prefix() Matches identifies, numbers, prefix operators and plugged in grammar matchers.
protected void	pushOp(Operator op, Token tok) The pushOp function is worth some explanation Say 1+2*3 is parsed.

Methods inherited from class com.singularsys.jep.configurableparser.ShuntingYard

compareOps, dumpState, expression, getIterator, parse, prefixSuffix, setIterator

Methods inherited from class java.lang.Object

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

Field Detail

posns

protected java.util.Stack<com.singularsys.jep.misc.lineNumbering.LineNumberingShuntingYard.Position> posns

Stack to track positions when pushing and popping operators

Constructor Detail

LineNumberingShuntingYard

public LineNumberingShuntingYard(Jep jep,
                                 java.util.List<GrammarMatcher> gm)

Constructor

Parameters:

jep -

gm -

Method Detail

parseSubExpression

public Node parseSubExpression()
                        throws ParseException

Description copied from class: ShuntingYard

Callback function used by GrammerMatchers

Specified by:

parseSubExpression in interface GrammarParser

Overrides:

parseSubExpression in class ShuntingYard

Returns:

the root node of the matched sub expression.

Throws:

ParseException

popOp

protected void popOp()
              throws ParseException

Description copied from class: ShuntingYard

Pops an operator off the Operator stack, and creates a new node. The children of the node are poped off the node stack and the result is pushed onto the node stack.

Overrides:

popOp in class ShuntingYard

Throws:

ParseException

prefix

protected void prefix()
               throws ParseException

Description copied from class: ShuntingYard

Matches identifies, numbers, prefix operators and plugged in grammar matchers.

Overrides:

prefix in class ShuntingYard

Throws:

ParseException

pushOp

protected void pushOp(Operator op,
                      Token tok)
               throws ParseException

Description copied from class: ShuntingYard

The pushOp function is worth some explanation Say 1+2*3 is parsed. First + is pushed onto the stack, then * is pushed. For 1*2+3. * is pushed, when + is encountered * has tighter precedence so it and the top two elements from the node stack are popped, the result computed and pushed on the node stack. Special cases -1+2 [uminus,+],[1] -> [+],[-1] -> [+],[-1,2] -> [],[(-1)+2] -1^2 [uminus,^],[1] -> [uminus,^],[1] -> [uminus,^],[1,2] -> [uminus],[1^2] -> [],[-(1^2)] 1^-2 [^],[1] -> [^,uminus],[1] ->[^,uminus],[1,2] -> [^],[1,(-2)] ->[],[1^(-2)]

Overrides:

pushOp in class ShuntingYard

tok - Token operator came from

Throws:

ParseException