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tried to fix few things #2

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tried to fix few things #2

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48ab262
removed the useless filter method
Apr 23, 2018
1fb3183
unused property
Apr 23, 2018
b93c8ad
removed the unaccessed if statement
Apr 23, 2018
6777780
removed the || {}
Apr 23, 2018
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13 changes: 4 additions & 9 deletions src/main.js
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Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,6 @@ var firstFollow = (function() {
// remove spaces, filter empty lines, and break the rules into (production, derivations)
return grammar.split(/;|\n/).map(function(line) {
return line.trim();
}).filter(function(line) {
return line;
}).map(function(rule) {
var data = rule.split(/->|→/);
if (data.length < 2 || !data[0]) {
Expand All @@ -43,7 +41,6 @@ var firstFollow = (function() {

var Grammar = function(str) {
var that = this;
this.grammar = str;
this.productionList = GetProductions(str);
if (!this.productionList.length) {
throw 'Empty grammar';
Expand Down Expand Up @@ -125,10 +122,8 @@ var firstFollow = (function() {
var symbol = prod.symbol;
var derivationList = prod.derivation;

if (!that.isNonTerminal(symbol)) {
that.addToFirstSet(symbol, symbol);
}
else {


// set to true when the first derivation has epsilon in its first set,
// it remains true as long as the subsequent derivations also contain '' in their first sets.
var addEpsilon = false;
Expand All @@ -138,7 +133,7 @@ var firstFollow = (function() {
}
else {
if (index === 0 || addEpsilon) {
var fSet = that.firstSet[derivation] || {};
var fSet = that.firstSet[derivation] ;

// only add epsilon to firt(X) if epsilon is in all k for X -> Y1, Y2...Yk
addEpsilon = '' in fSet;
Expand Down Expand Up @@ -188,7 +183,7 @@ var firstFollow = (function() {
if (addEpsilon) {
that.addToFirstSet(symbol, '');
}
}

});
// we stop iterating and consider that the sets are complete when after a iteration nothing was added to them.
} while(this._changed);
Expand Down