Simple precedence parser: Difference between revisions

Revision as of 16:36, 9 August 2010

Revision as of 12:24, 27 September 2010

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{{Unreferenced stub|auto=yes|date=December 2009}}

In computer science, a '''Simple precedence parser''' is a type of [[bottom-up parser]] for [[context-free grammars]] that can be used only by [[Simple precedence grammar]]s.

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* While not (Stack equals to $S and Input equals to $) (S = Initial symbol of the grammar)

** Search in the table the relationship between Top(stack) and NextToken(Input)

** if the relationship is <Math> \dot =</math> or <Math>\lessdot</math>

*** '''Shift''':

*** Push(Stack, relationship)

*** Push(Stack, NextToken(Input))

*** RemoveNextToken(Input)

** if the relationship is <Math>\gtrdot</math>

*** '''Reduce''':

*** SearchProductionToReduce(Stack)

*** RemovePivot(Stack)

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| ||E|| E' || T || T' || F || + ||*||(||)||num || $

|-

| E || || || || || ||<math>\dot =</math>|| || ||<math>\gtrdot</math> || ||<math>\gtrdot</math>

|-

| E'|| || || || || || || || ||<math>\dot =</math>|| ||

|-

| T || || || || || ||<math>\gtrdot</math>||<math>\dot =</math>|| ||<math>\gtrdot</math>|| ||<math>\gtrdot</math>

|-

| T'|| || || || || ||<math>\gtrdot</math>|| || ||<math>\gtrdot</math>|| ||<math>\gtrdot</math>

|-

| F || || || || || ||<math>\gtrdot</math>||<math>\gtrdot</math>|| ||<math>\gtrdot</math>|| ||<math>\gtrdot</math>

|-

| + || || ||<math>\lessdot</math>||<math>\dot =</math>||<math>\lessdot</math>|| || ||<math>\lessdot</math>|| ||<math>\lessdot</math> ||

|-

| * || || || || ||<math>\dot =</math>|| || ||<math>\lessdot</math>|| ||<math>\lessdot</math> ||

|-

| ( ||<math>\lessdot</math>||<math>\dot =</math>||<math>\lessdot</math>||<math>\lessdot</math>||<math>\lessdot</math>|| || ||<math>\lessdot</math>|| ||<math>\lessdot</math> ||

|-

| ) || || || || || ||<math>\gtrdot</math>||<math>\gtrdot</math>|| ||<math>\gtrdot</math>|| ||<math>\gtrdot</math>

|-

| num|| || || || || ||<math>\gtrdot</math>||<math>\gtrdot</math>||||<math>\gtrdot</math>|| ||<math>\gtrdot</math>

|-

| $ ||<math>\lessdot</math>|| ||<math>\lessdot</math>||<math>\lessdot</math>||<math>\lessdot</math>|| || ||<math>\lessdot</math>|| ||<math>\lessdot</math> ||

|}