Lexer refactor; updated engine

ajlopez · Dec 12, 2020 · 04a209d · 04a209d
1 parent c4dd8bd
commit 04a209d
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Showing 2 changed files with 34 additions and 44 deletions.
diff --git a/lib/lexers.js b/lib/lexers.js
@@ -1,17 +1,17 @@
 
-var TokenType = { Integer: 1, String: 2, Name: 3, Punctuation: 4, Operator: 5 };
+const TokenType = { Integer: 1, String: 2, Name: 3, Punctuation: 4, Operator: 5 };
 
-var punctuations = ".,()";
-var operators = [ ">", "<", "=", ">=", "<=", "<>" ];
+const punctuations = ".,()";
+const operators = [ ">", "<", "=", ">=", "<=", "<>" ];
 
 function Token(value, type) {
     this.value = value;
     this.type = type;
 }
 
 function Lexer(text) {
-    var position = 0,
-        nexts = [];
+    let position = 0;
+    const nexts = [];
 
     function nextChar() {
         return text[position++];
@@ -74,8 +74,8 @@ function Lexer(text) {
     }
 
     function nextName(letter) {
-        var name = letter,
-            ch;
+        let name = letter;
+        let ch;
 
         for (ch = nextChar(); ch && (isLetter(ch) || isDigit(ch) || ch === '-'); ch = nextChar()) {
             name += ch;
@@ -87,39 +87,38 @@ function Lexer(text) {
     }
 
     function nextOperator(letter) {
-        var ch = nextChar(),
-            value = letter + ch;
+        const ch = nextChar();
+        const value = letter + ch;
 
-        if (operators.indexOf(value) >= 0) {
+        if (operators.indexOf(value) >= 0)
             return new Token(value, TokenType.Operator);
-        }
 
         pushChar(ch);
 
         return new Token(letter, TokenType.Operator);
     }
 
     function nextString() {
-        var name = '',
-            ch;
+        let name = '';
+        let ch;
 
         for (ch = nextChar(); ch && ch !== '"'; ch = nextChar()) {
             name += ch;
+
             if (ch === '\\') {
                 name += nextChar();
             }
         }
 
-        if (!ch) {
+        if (!ch)
             throw "unclosed string";
-        }
 
         return new Token(name, TokenType.String);
     }
 
     function nextNumber(digit) {
-        var number = digit,
-            ch;
+        let number = digit;
+        let ch;
 
         for (ch = nextChar(); ch && isDigit(ch); ch = nextChar()) {
             number += ch;
@@ -131,11 +130,11 @@ function Lexer(text) {
     }
 
     this.nextPhrase = function () {
-        var lastchar = null,
-            lastposition = null,
-            l = text.length,
-            initial,
-            ch;
+        let lastchar = null;
+        let lastposition = null;
+        const l = text.length;
+        let initial;
+        let ch;
 
         skipSpaces();
 
@@ -156,55 +155,46 @@ function Lexer(text) {
             position++;
         }
 
-        if (lastchar === '.') {
+        if (lastchar === '.')
             return text.slice(initial, lastposition);
-        }
 
         throw "unexpected end of input";
     }
 
     this.nextToken = function () {
-        if (nexts.length > 0) {
+        if (nexts.length > 0)
             return nexts.pop();
-        }
 
-        var ch = nextFirstChar();
+        const ch = nextFirstChar();
 
-        if (ch === null) {
+        if (ch === null)
             return null;
-        }
 
-        if (isLetter(ch)) {
+        if (isLetter(ch))
             return nextName(ch);
-        }
 
-        if (isDigit(ch)) {
+        if (isDigit(ch))
             return nextNumber(ch);
-        }
 
-        if (isOperator(ch)) {
+        if (isOperator(ch))
             return nextOperator(ch);
-        }
 
-        if (ch === '"') {
+        if (ch === '"')
             return nextString();
-        }
 
-        if (punctuations.indexOf(ch) >= 0) {
+        if (punctuations.indexOf(ch) >= 0)
             return new Token(ch, TokenType.Punctuation);
-        }
 
         throw "unexpected '" + ch + "'";
     }
 
     this.pushToken = function(token) {
-        if (token) {
+        if (token)
             nexts.push(token);
-        }
     }
 
     this.peekToken = function () {
-        var token = this.nextToken();
+        const token = this.nextToken();
 
         if (token)
             this.pushToken(token);

diff --git a/package.json b/package.json
@@ -5,13 +5,13 @@
 , "author": "Angel 'Java' Lopez <webmaster@ajlopez.com> (http://www.ajlopez.com)"
 , "repository": { "type": "git", "url": "git://github.com/ajlopez/CobolScript.git" }
 , "main": "./lib/cobolscript.js"
-, "engines": { "node": ">= 0.6.0 && < 0.9.0" }
+, "engines": { "node": ">= 8.0.0" }
 , "scripts": {
     "test": "simpleunit test"
   }
 , "dependencies": {
   }
 , "devDependencies": {
-    "simpleunit": "0.0.4"
+    "simpleunit": "0.0.9"
   }
 }