moo - npm Package Compare versions

Comparing version 0.5.1 to 0.5.2

moo.js

@@ -56,2 +56,34 @@ (function(root, factory) {
 
+  function pad(s, length) {
+    if (s.length > length) {
+      return s
+    }
+    return Array(length - s.length + 1).join(" ") + s
+  }
+
+  function lastNLines(string, numLines) {
+    var position = string.length
+    var lineBreaks = 0;
+    while (true) {
+      var idx = string.lastIndexOf("\n", position - 1)
+      if (idx === -1) {
+        break;
+      } else {
+        lineBreaks++
+      }
+      position = idx
+      if (lineBreaks === numLines) {
+        break;
+      }
+      if (position === 0) {
+        break;
+      }
+    }
+    var startPosition = 
+      lineBreaks < numLines ?
+      0 : 
+      position + 1
+    return string.substring(startPosition).split("\n")
+  }
+
   function objectToRules(object) {
@@ -339,4 +371,8 @@ var keys = Object.getOwnPropertyNames(object)
   function keywordTransform(map) {
-    var reverseMap = Object.create(null)
-    var byLength = Object.create(null)
+
+    // Use a JavaScript Map to map keywords to their corresponding token type
+    // unless Map is unsupported, then fall back to using an Object:
+    var isMap = typeof Map !== 'undefined'
+    var reverseMap = isMap ? new Map : Object.create(null)
+
     var types = Object.getOwnPropertyNames(map)
@@ -348,27 +384,15 @@ for (var i = 0; i < types.length; i++) {
       keywordList.forEach(function(keyword) {
-        (byLength[keyword.length] = byLength[keyword.length] || []).push(keyword)
         if (typeof keyword !== 'string') {
           throw new Error("keyword must be string (in keyword '" + tokenType + "')")
         }
-        reverseMap[keyword] = tokenType
+        if (isMap) {
+          reverseMap.set(keyword, tokenType)
+        } else {
+          reverseMap[keyword] = tokenType
+        }
       })
     }
-
-    // fast string lookup
-    // https://jsperf.com/string-lookups
-    function str(x) { return JSON.stringify(x) }
-    var source = ''
-    source += 'switch (value.length) {\n'
-    for (var length in byLength) {
-      var keywords = byLength[length]
-      source += 'case ' + length + ':\n'
-      source += 'switch (value) {\n'
-      keywords.forEach(function(keyword) {
-        var tokenType = reverseMap[keyword]
-        source += 'case ' + str(keyword) + ': return ' + str(tokenType) + '\n'
-      })
-      source += '}\n'
+    return function(k) {
+      return isMap ? reverseMap.get(k) : reverseMap[k]
     }
-    source += '}\n'
-    return Function('value', source) // type
   }
@@ -392,2 +416,3 @@
     this.queuedToken = info ? info.queuedToken : null
+    this.queuedText = info ? info.queuedText: "";
     this.queuedThrow = info ? info.queuedThrow : null
@@ -406,2 +431,3 @@ this.setState(info ? info.state : this.startState)
       queuedToken: this.queuedToken,
+      queuedText: this.queuedText,
       queuedThrow: this.queuedThrow,
@@ -538,3 +564,4 @@ }
     if (group.shouldThrow) {
-      throw new Error(this.formatError(token, "invalid syntax"))
+      var err = new Error(this.formatError(token, "invalid syntax"))
+      throw err;
     }
@@ -580,9 +607,24 @@
     }
-    var start = Math.max(0, token.offset - token.col + 1)
-    var eol = token.lineBreaks ? token.text.indexOf('\n') : token.text.length
-    var firstLine = this.buffer.substring(start, token.offset + eol)
-    message += " at line " + token.line + " col " + token.col + ":\n\n"
-    message += "  " + firstLine + "\n"
-    message += "  " + Array(token.col).join(" ") + "^"
-    return message
+    
+    var numLinesAround = 2
+    var firstDisplayedLine = Math.max(token.line - numLinesAround, 1)
+    var lastDisplayedLine = token.line + numLinesAround
+    var lastLineDigits = String(lastDisplayedLine).length
+    var displayedLines = lastNLines(
+        this.buffer, 
+        (this.line - token.line) + numLinesAround + 1
+      )
+      .slice(0, 5)
+    var errorLines = []
+    errorLines.push(message + " at line " + token.line + " col " + token.col + ":")
+    errorLines.push("")
+    for (var i = 0; i < displayedLines.length; i++) {
+      var line = displayedLines[i]
+      var lineNo = firstDisplayedLine + i
+      errorLines.push(pad(String(lineNo), lastLineDigits) + "  " + line);
+      if (lineNo === token.line) {
+        errorLines.push(pad("", lastLineDigits + token.col + 1) + "^")
+      }
+    }
+    return errorLines.join("\n")
   }
@@ -589,0 +631,0 @@

package.json

 {
   "name": "moo",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "description": "Optimised tokenizer/lexer generator! 🐄 Much performance. Moo!",
@@ -5,0 +5,0 @@ "main": "moo.js",

README.md

@@ -243,8 +243,6 @@ ![](cow.png)
 
-You can use [itt](https://github.com/nathan/itt)'s iterator adapters to make constructing keyword objects easier:
+You can use `Object.fromEntries` to easily construct keyword objects:
 
 ```js
-    itt(['class', 'def', 'if'])
-    .map(k => ['kw-' + k, k])
-    .toObject()
+Object.fromEntries(['class', 'def', 'if'].map(k => ['kw-' + k, k]))
 ```
@@ -274,3 +272,3 @@
         lbrace:   {match: '{', push: 'main'},
-        rbrace:   {match: '}', pop: true},
+        rbrace:   {match: '}', pop: 1},
         colon:    ':',
@@ -282,3 +280,3 @@ space:    {match: /\s+/, lineBreaks: true},
         escape:   /\\./,
-        strend:   {match: '`', pop: true},
+        strend:   {match: '`', pop: 1},
         const:    {match: /(?:[^$`]|\$(?!\{))+/, lineBreaks: true},
@@ -356,6 +354,6 @@ },
 
-Use [itt](https://github.com/nathan/itt)'s iteration tools with Moo.
+Use [itt](https://www.npmjs.com/package/itt)'s iteration tools with Moo.
 
 ```js
-    for (let [here, next] = itt(lexer).lookahead()) { // pass a number if you need more tokens
+    for (let [here, next] of itt(lexer).lookahead()) { // pass a number if you need more tokens
       // enjoy!
@@ -362,0 +360,0 @@ }

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Improved metrics

Total package byte prevSize

32679

increased by2.69%

Lines of code

560

increased by7.28%

Worsened metrics

Number of lines in readme file

384

decreased by-0.52%

No dependency changes