The framework can output equivalent parsers natively in C/C++/C#/Java/PHP/JavaScript. Developed with TDD since 2008.
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README.md

#NPEG - .NET Parsing Expression Grammar.

  • The framework can output equivalent parsers natively in C/C++/C#/Java/PHP/JavaScript. Tool Here
  • The framework can read and write it's own DSL. DSL Documentation.

The inline DSL is only supported in C#. All other languages must use the DSL inside the language workbench to export the parse tree in your target language. All offline versions will be faster so we provide an offline C# version also. You can grab dependencies for your target language here: https://github.com/leblancmeneses/NPEG/tree/master/Languages

##How to get started Watch this pair programming session as Leblanc writes a math expression solver.

##Nuget Packages Offline version which requires exporting the parse tree using the language workbench.

Install-Package RobustHaven.Text.Npeg

Online version that allows building the parse tree from a string using the NPEG DSL.

Install-Package NPEG

PEG - Boolean Algebra in CSharp

		String grammar = @"

				S: [\s]+;
                (?<Gate>): ('*' / 'AND') / ('~*' / 'NAND') / ('+' / 'OR') / ('~+' / 'NOR') / ('^' / 'XOR') / ('~^' / 'XNOR');
                ValidVariable: '""' (?<Variable>[a-zA-Z0-9]+) '""'  / '\'' (?<Variable>[a-zA-Z0-9]+) '\'' / (?<Variable>[a-zA-Z]);
                VarProjection1: ValidVariable /  (?<Invertor>'!' ValidVariable);
                VarProjection2: VarProjection1 / '(' Expression ')' / (?<Invertor>'!' '(' Expression ')');
                Expression: S? VarProjection2 S? (Gate S? VarProjection2 S?)*;
                (?<BooleanEquation>): Expression !.;
            "
				.Trim();

		AExpression ROOT = PEGrammar.Load(grammar);
		var iterator = new StringInputIterator("((((!X*Y*Z)+(!X*Y*!Z)+(X*Z))))");
		var visitor = new NpegParserVisitor(iterator);
		ROOT.Accept(visitor);
		Assert.IsTrue(visitor.IsMatch);
		AstNode node = visitor.AST;

PEG - Mathematical Formula in CSharp

		AExpression ROOT = PEGrammar.Load(
			@"
                (?<Value>): [0-9]+ / '(' Expr ')';
                (?<Product>): Value ((?<Symbol>'*' / '/') Value)*;
                (?<Sum>): Product ((?<Symbol>'+' / '-') Product)*;
                (?<Expr>): Sum;
            "
			);

		String input = "((((12/3)+5-2*(81/9))+1))";
		var iterator = new StringInputIterator(input);
		var visitor = new NpegParserVisitor(iterator);

		ROOT.Accept(visitor);
		Assert.IsTrue(visitor.IsMatch);
		AstNode node = visitor.AST;

PEG - Mathematical Formula in C

#include <assert.h>
#include <stdio.h>
#include <string.h>

#include "robusthaven/text/npeg.h"
#include "robusthaven/text/npeg_inputiterator.h"
#include "robusthaven/structures/stack.h"

#include "MathematicalFormula.h"

#define BUFFER_SIZE 100

int main(int argc, char *argv[])
{
  const char text1[] = "(1*3+4)/5*93";
  const char text2[] = "9+(9-8)*10";  

  char buffer[BUFFER_SIZE];
  rh_stack_instance disableBackReferenceStack;
  rh_stackstack_instance sandbox;
  rh_hashmap_instance backreference_lookup;
  rh_list_instance warnings;
  rh_stack_instance errors;
  npeg_context context;
  npeg_inputiterator iterator;
  npeg_astnode* ast, *p_child;

  int (*parsetree)(npeg_inputiterator*, npeg_context*) = &MathematicalFormula_impl_0;
  int IsMatch = 0;

  // load npeg managed memory
  context.disableBackReferenceStack = &disableBackReferenceStack;
  context.sandbox = &sandbox;
  context.backReferenceLookup = &backreference_lookup;
  context.warnings = &warnings; 
  context.errors = &errors;

  npeg_inputiterator_constructor(&iterator, text1, strlen(text1));
  npeg_constructor(&context, NULL);

  IsMatch = parsetree(&iterator, &context);
  assert(IsMatch);
  printf("\tVerified: The expected input was matched by parser.\n");

  ast = npeg_get_ast(&context);
  npeg_printVisitor(ast, NULL);
  assert(0 == strcmp(ast->token->name, "EXPRESSION"));
  printf("\tVerified: The expected token name: '%s'.\n", ast->token->name);
  npeg_inputiterator_get_text(buffer, &iterator, ast->token->start, ast->token->end);
  assert(0 == strcmp(buffer, text1));
  printf("\tVerified: The expected matched string: '%s'.\n", buffer);

PEG - Mathematical Formula in C++

#include <cstdio>
#include <cassert>
#include <iostream>
#include <cstring>
#include "robusthaven/text/StringInputIterator.h"
#include "robusthaven/text/PrintVisitor.h"
#include "MathematicalFormula.h"

using namespace RobustHaven::Text;
using namespace std;

#define BUFFER_SIZE 100

int main(int argc, char *argv[])
{
  const char text1[] = "(1*3+4)/5*93";
  const char text2[] = "9+(9-8)*10";  

  char buffer[BUFFER_SIZE];
  InputIterator* input; 
  MathematicalFormula* context; 
  AstNode *ast, *p_child;

  input = new StringInputIterator(text1, strlen(text1));
  context = new MathematicalFormula(input);
  assert(context->isMatch());
  cout << "\tVerified: Matching of input succeeds\n";
  ast = context->getAST();
  PrintVisitor::printAST(*ast);
  assert(ast->getToken()->getName() == "EXPRESSION");
  printf("\tVerified: The expected token name: '%s'.\n", ast->getToken()->getName().c_str());
  input->getText(buffer, ast->getToken()->getStart(), ast->getToken()->getEnd());
  assert(0 == strcmp(buffer, text1));
  printf("\tVerified: The expected matched string: '%s'.\n", buffer);

PEG - Mathematical Formula in Java

package parser_tests;
import robusthaven.text.npeg.tests.parsers.MathematicalFormula;
import robusthaven.text.*;
import junit.framework.Assert;
import junit.framework.TestCase;
import java.util.*;
import java.io.*;

public class MathematicalFormulaTest extends TestCase {
	static final String text1 = "(1*3+4)/5*93";
	static final String text2 = "9+(9-8)*10";  

	InputIterator input;
	MathematicalFormula parser;
	AstNode ast, child;
	
	public void testInput1() {
	String capturedText;

	try {
		input = new StringInputIterator(text1);
		parser = new MathematicalFormula(input);

		Assert.assertTrue(parser.isMatch());
		System.out.println("\tVerified: Matching of input succeeds\n");
	
		ast = parser.getAST();
		PrintVisitor.printAST(ast);
		Assert.assertTrue(0 == ast.getToken().getName().compareTo("EXPRESSION"));
		System.out.println("\tVerified: The expected token name: " + ast.getToken().getName());

PEG - Mathematical Formula in Javascript

.. framework has been "started" but no tests created yet

PEG - Mathematical Formula in PHP

.. framework has been "started" but no tests created yet