incr-regex-package/src/rxprint.js

An incremental regular expression parser in JavaScript; useful for input validation, RegExp

// module: rxprint.js
/** 
 * Copyright (c) 2016, Nurul Choudhury
 * 
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 */

"use strict";
import { DONE,dot,matchable } from './rxtree';

export function printExpr(exp,paren) {
  if( paren && exp && exp.oper) return "(" + printExpr(exp) + ")";
  if(exp && exp.oper ) {
    if( exp.oper.type == 'B' ) {
      if(exp.oper.op == '.') return "("+printExpr(exp.left) + "." +printExpr(exp.right)+")";
      return "(" + printExpr(exp.left) + "|" + printExpr(exp.right) + ")";
    }
    else if( exp.oper.type == 'U' ) {
      return "("+printExpr(exp.left,false)+  exp.oper.val + ")";
    }
  }
  else if( exp === DONE) return "<DONE>";
  else return exp.val;
}

export function printExprS(exp,ctxPriority) {
  if(exp && exp.oper ) {
    if( exp.oper.type == 'B' ) {
      if(exp.oper.op == '.') 
      	return ctxPriority > 2 ? "(" + printExprS(exp.left,2) + printExprS(exp.right,2) +")":
                               printExprS(exp.left,2) + printExprS(exp.right,2);
        return ctxPriority > 1 ?"(" + printExprS(exp.left,1) + "|" + printExprS(exp.right,1) + ")":
      					  printExprS(exp.left,ctxPriority+1) + "|" + printExprS(exp.right,ctxPriority)
    }
    else if( exp.oper.type == 'U' ) {
      return ctxPriority > 3  ? "(" + printExprS(exp.left,1)+ ")" + exp.oper.val:
      							  printExprS(exp.left,3)+  exp.oper.val;
    }
  }
  else if( exp === DONE) return "<DONE>";
  else return (exp.val||'~~~');
}

export function printExprQ(exp,paren) {
  if( paren && exp && exp.oper) return "(" + printExprQ(exp) + ")";
  if(exp && exp.oper ) {
    if( exp.oper.type == 'B' ) {
      if(exp.oper.op == '.') return "("+printExprQ(exp.left) + "." +printExprQ(exp.right)+")";
      return "(" + printExprQ(exp.left) + "|" + printExprQ(exp.right) + ")";
    }
    else if( exp.oper.type == 'U' ) {
      return "("+printExprQ(exp.left,false)+  exp.oper.val + ")";
    }
  }
  else if( exp === DONE) return "<DONE>";
  else return "'"+(exp.val||'~~~')+"'";
}

export function printExprN(exp,paren) {
  if( paren && exp && exp.oper) return "(" + printExpr(exp) + ")";
  if(exp && exp.oper ) {
    if( exp.oper.type == 'B' ) {
      if(exp.oper.op == '.') {
        if( exp.nextNode) 
          return "("+printExprN(exp.left) + "." +printExprN(exp.nextNode)+")";
        else return printExprN(exp.left);
      }  
      return "(" + printExprN(exp.left) + "|" + printExprN(exp.right) + ")";
    }
    else if( exp.oper.type == 'U' ) {
      if( exp.nextNode ) {
         return "(("+printExpr(exp.left,false)+  exp.oper.val + ")." + printExprN(exp.nextNode)+ ")";
      }
      return "("+printExpr(exp.left,false)+  exp.oper.val + ")";
    }
  }
  else if( exp === DONE) return "<DONE>";
  else {
    if( exp && exp.nextNode ) return "("+(exp.val||'~~~') + "." +printExprN(exp.nextNode)+")";
    return exp ? exp.val: '';
  }
}