Lalr parser - xml table output, Programming Languages

LALR Parser:

Rule Table - Contains definitions of production rules within the grammar.

Attributes:

  • Count - Number of production rules in the table

Child items:

  • Rule

Rule - Defines a given production rule in the grammar.  Each production rule has a Left Hand Side (LHS) which is a single non-terminal) and a Right Hand Side (RHS), which can be a mix of terminals and non-terminals.  This structure can be used to determine how many and which symbols to pop off the parser stack during a reduction.  The LHS symbol must be placed on the parser stack to complete the rule reduction.

Attributes:

  • Index - Unique identifier of rule in the rule table
  • NonTerminalIndex - Provides the index for the non-terminal symbol (LHS) in the symbol table.
  • Symbol Count - number of symbols in the RHS of the production

Child items:

  • Rule Symbol

Rule Symbol - Defines a terminal or non-terminal in the RHS of the rule.  Symbols are listed in order of appearance on the RHS (from leftmost to rightmost). 

Attributes:

  • SymbolIndex - Provides the index into the symbol table for the particular symbol on the RHS of the production

LALR Table - This structure represents the LALR parse table.  Recall from class that the LALR table has symbols (terminals and non-terminals) on its X-Axis and LALR states on its Y-Axis (refer to class slides).  This table is defined in terms of states, which call out the appropriate symbols that are applicable to that state.

Attributes:

  • Count - Total number of LALR states in the table
  • Initial State - Start state for the parser (nominally state 0)

Child items:

  • LALR State

LALR State - This item defines a given state in the LALR parse table.  Each state is mapped to one or more symbols.  For each mapping, an action is specified (shift, reduce, goto, or accept).  If a state does not reference a symbol, then no action is specified when the parser is in that state and the symbol is at the front of the input queue-in short, this is a parser error.

Attributes:

  • Index - State number within the table
  • Action count - Number of actions associated with a given state (at least one)

Child items:

  • LALR Action

LALR Action - This item defines the action for a given state-symbol pair.  Since the LALR Action is a child of LALR State, all listed actions are associated with the parent state.  Each pair will have a single mapping associated with it of type:  shift, reduce, goto, or accept. 

Attributes:

  • SymbolIndex - The index of the symbol mapped to the LALR state for this action.
  • Action - The type of action being accomplished.  Actions:  1- Shift, 2- Reduce, 3 - Goto, 4 - Accept.
  • Value - The meaning of this value is dependent on the action type.  For a shift or goto action, the value refers to the next LALR state.  For a reduce action, the value refers to the rule index in the Rule Table.  For an accept action, the value is meaningless (nominally 0) as it ends the parsing process for a given statement.

 

 

 

Best Programming Strategy:

  • Mimic the GPB XML structure
  • Implement each structure that has items as an array of objects

 

 

Posted Date: 3/25/2013 5:49:01 AM | Location : United States







Related Discussions:- Lalr parser - xml table output, Assignment Help, Ask Question on Lalr parser - xml table output, Get Answer, Expert's Help, Lalr parser - xml table output Discussions

Write discussion on Lalr parser - xml table output
Your posts are moderated
Related Questions
'This program compares interest rates between two banks and determines the best bank 'Eric Weber, Adam Litchfield, Eric Romero, Sarah, Alex, Amy '10/5/12 'Lab #4 Problem 42 'CSC

The next major set of tasks to tackle are delete and update. Version control systems typically version updates to a ?le and only store the differences between the ?les. Two system

HOW CAN I DESIGN A MOBILE WEB BROWSER LIKE OPERA MINI. USING VISUAL BASIC? HELP ME.

I need help programming an arduino uno to scan an ean-8 student barcode and display their name and id on computer. This is a capstone project.

I need someone to make an ER diagram.

Computers and Programming Concept 1. Classify computer systems according to capacity. How they are different from computers according to the classification of technology. Provi

Create a logical expression that corresponds to the following statement: If you like talking about computers or playing video games at LAN parties, and you want to meet others w

1. use a small perl program and matching config file to retrieve and reformat the system time for a number of remote machines via snmp.  Readings should have a local timestamp for

Expertsmind.com is expert in java assignment help JAVA Virtual Machine A Java exclusive device or java virtual machine (JVM) is an exclusive device able of undertaking Jav

Let S =  {s 1 , s 2 , .... , s k } denote a set of k genomes. The problem of fingerprinting is the task of identifying a shortest possible substring α i from each string si such t