function-composer - npm Package Compare versions

Comparing version 0.2.0 to 0.3.0

examples/custom_type.js

@@ -10,3 +10,3 @@ var compose = require('../function-composer');
 // register a test for this new type
-compose.tests['Person'] = function (x) {
+compose.types['Person'] = function (x) {
   return x instanceof Person;
@@ -13,0 +13,0 @@ };

function-composer.js

@@ -22,5 +22,12 @@ /**
   // order types
-  // object will be ordered last as other types may be an object too.
+  // anytype (*) will be ordered last, and then object, as other types may be
+  // an object too.
   function compareTypes(a, b) {
-    return a === 'Object' ? 1 : b === 'Object' ? -1 : 0
+    if (a === '*') return 1;
+    if (b === '*') return -1;
+
+    if (a === 'Object') return 1;
+    if (b === 'Object') return -1;
+
+    return 0;
   }
@@ -34,45 +41,138 @@
   /**
-   * Compose a function from sub-functions each handling a single type signature.
-   * @param {string} [name]  An optional name for the function
-   * @param {Object.<string, function>} signatures
-   *            A map with the type signature as key and the sub-function as value
-   * @return {function} Returns the composed function
+   * Collection with function definitions (local shortcuts to functions)
+   * @constructor
    */
-  function compose(name, signatures) {
-    if (!signatures) {
-      signatures = name;
-      name = null;
-    }
+  function Defs() {}
 
-    var normalized = {};  // normalized function signatures
-    var defs = {   // function definitions (local shortcuts to functions)
-      signature: [],
-      test: [],
-      convert: []
-    };
-    function addDef(fn, type) {
-      var index = defs[type].indexOf(fn);
-      if (index == -1) {
-        index = defs[type].length;
-        defs[type].push(fn);
-      }
-      return type + index;
+  /**
+   * Add a function definition.
+   * @param {function} fn
+   * @param {string} [type='fn']
+   * @returns {string} Returns the function name, for example 'fn0' or 'signature2'
+   */
+  Defs.prototype.add = function (fn, type) {
+    type = type || 'fn';
+    if (!this[type]) this[type] = [];
+
+    var index = this[type].indexOf(fn);
+    if (index == -1) {
+      index = this[type].length;
+      this[type].push(fn);
     }
+    return type + index;
+  };
 
-    // analise all signatures
-    var argumentCount = 0;
-    var parameters = {};
-    Object.keys(signatures).forEach(function (signature) {
-      var fn = signatures[signature];
-      var params = (signature !== '') ? signature.split(',').map(function (param) {
+  /**
+   * Create code lines for all definitions
+   * @param [name='defs']
+   * @returns {Array} Returns the code lines containing all function definitions
+   */
+  Defs.prototype.code = function (name) {
+    var me = this;
+    var code = [];
+    name = name || 'defs';
+
+    Object.keys(this).forEach(function (type) {
+      var def = me[type];
+      def.forEach(function (def, index) {
+        code.push('var ' + type + index + ' = ' + name + '[\'' + type + '\'][' + index + '];');
+      });
+    });
+
+    return code;
+  };
+
+  /**
+   * A function signature
+   * @param {string | Array.<string>} params  Array with the type(s) of each parameter,
+   *                                          or a comma separated string with types
+   * @param {function} fn                     The actual function
+   * @constructor
+   */
+  function Signature(params, fn) {
+    if (typeof params === 'string') {
+      this.params = (params !== '') ? params.split(',').map(function (param) {
         return param.trim();
       }) : [];
-      var normSignature = params.join(',');
-      normalized[normSignature] = fn;
-      argumentCount = Math.max(argumentCount, params.length);
+    }
+    else {
+      this.params = params;
+    }
+    this.fn = fn;
+  }
 
-      // get the entry for this number of arguments
-      var obj = parameters[params.length];
+  // TODO: implement function Signature.split
+  // TODO: implement function Signature.merge
+  // TODO: implement function Signature.toString
+
+  /**
+   * split all raw signatures into an array with splitted params
+   * @param {Object.<string, function>} rawSignatures
+   * @return {Array.<{params: Array.<string>, fn: function}>} Returns splitted signatures
+   */
+  function splitSignatures(rawSignatures) {
+    return Object.keys(rawSignatures).map(function (params) {
+      var fn = rawSignatures[params];
+      return new Signature(params, fn);
+    });
+
+    // TODO: split params containing an '|' into multiple entries
+  }
+
+  /**
+   * create a map with normalized signatures as key and the function as value
+   * @param {Array.<{params: Array.<string>, fn: function}>} signatures   An array with splitted signatures
+   * @return {{}} Returns a map with normalized signatures
+   */
+  function normalizeSignatures(signatures) {
+    var normalized = {};
+
+    signatures.map(function (entry) {
+      var signature = entry.params.join(',');
+      if (signature in normalized) {
+        throw new Error('Error: signature "' + signature + '" defined twice');
+      }
+      normalized[signature] = entry.fn;
+    });
+
+    return normalized
+  }
+
+  /**
+   * create an array with for every parameter an array with possible types
+   * @param {Array.<{params: Array.<string>, fn: function}>} signatures   An array with splitted signatures
+   * @return {Array.<Array.<string>>} Returns an array with allowed types per parameter
+   */
+  function splitTypes(signatures) {
+    var types = [];
+
+    signatures.forEach(function (entry) {
+      entry.params.forEach(function (param, i) {
+        if (!types[i]) {
+          types[i] = [];
+        }
+        if (types[i].indexOf(param) == -1) {
+          types[i].push(param);
+        }
+      });
+    });
+
+    return types;
+  }
+
+  /**
+   * create a recursive tree for traversing the number and type of parameters
+   * @param {Array.<{params: Array.<string>, fn: function}>} signatures   An array with splitted signatures
+   * @returns {{}}
+   */
+  function createParamsTree(signatures) {
+    var tree = {};
+
+    signatures.forEach(function (entry) {
+      var params = entry.params.concat([]);
+
+      // get the tree entry for the current number of arguments
+      var obj = tree[params.length];
       if (!obj) {
-        obj = parameters[params.length] = {
+        obj = tree[params.length] = {
           signature: [],
@@ -97,5 +197,26 @@ fn: null,
 
-      obj.fn = fn;
+      // add the function as leaf
+      obj.fn = entry.fn;
     });
 
+    return tree;
+  }
+
+  /**
+   * Compose a function from sub-functions each handling a single type signature.
+   * @param {string} [name]  An optional name for the function
+   * @param {Object.<string, function>} signatures
+   *            A map with the type signature as key and the sub-function as value
+   * @return {function} Returns the composed function
+   */
+  function compose(name, signatures) {
+    // handle arguments
+    if (!signatures) {
+      signatures = name;
+      name = null;
+    }
+
+    var defs = new Defs();
+    var structure = splitSignatures(signatures);
+
     function switchTypes(signature, args, prefix) {
@@ -105,3 +226,3 @@ var code = [];
       if (signature.fn !== null) {
-        var def = addDef(signature.fn, 'signature');
+        var def = defs.add(signature.fn, 'signature');
         code.push(prefix + 'return ' + def + '(' + args.join(', ') +'); // signature: ' + signature.signature);
@@ -113,9 +234,22 @@ }
             .sort(compareTypes)
-            .forEach(function (type) {
+            .forEach(function (type, index) {
               var arg = 'arg' + args.length;
-              var def = addDef(getTest(type), 'test') + '(' + arg + ')';
 
-              code.push(prefix + 'if (' + def + ') { // type: ' + type);
-              code = code.concat(switchTypes(signature.types[type], args.concat(arg), prefix + '  '));
-              code.push(prefix + '}');
+              var before;
+              var after;
+              var nextPrefix = prefix + '  ';
+              if (type == '*') {
+                before = (index > 0 ? 'else {' : '');
+                after  = (index > 0 ? '}' : '');
+                if (index == 0) {nextPrefix = prefix;}
+              }
+              else {
+                var def = defs.add(getTest(type), 'test') + '(' + arg + ')';
+                before = 'if (' + def + ') { // type: ' + type;
+                after  = '}';
+              }
+
+              if (before) code.push(prefix + before);
+              code = code.concat(switchTypes(signature.types[type], args.concat(arg), nextPrefix));
+              if (after) code.push(prefix + after);
             });
@@ -135,4 +269,4 @@
                 var arg = 'arg' + args.length;
-                var test = addDef(getTest(conversion.from), 'test') + '(' + arg + ')';
-                var convert = addDef(conversion.convert, 'convert') + '(' + arg + ')';
+                var test = defs.add(getTest(conversion.from), 'test') + '(' + arg + ')';
+                var convert = defs.add(conversion.convert, 'convert') + '(' + arg + ')';
 
@@ -144,3 +278,2 @@ code.push(prefix + 'if (' + test + ') { // type: ' + conversion.from + ', convert to ' + conversion.to);
             });
-
       }
@@ -151,14 +284,16 @@
 
-    var args = [];
-    for (var i = 0; i < argumentCount; i++) {
-      args.push('arg' + i);
+    var types = splitTypes(structure);
+    var params = [];
+    for (var i = 0; i < types.length; i++) { // we can't use .map here, some entries may be undefined
+      params.push('arg' + i);
     }
 
     var code = [];
-    var counts = Object.keys(parameters);
-    code.push('return function ' + (name || '') + '(' + args.join(', ') + ') {');
-    counts
+    var tree = createParamsTree(structure);
+    var paramCounts = Object.keys(tree);
+    code.push('return function ' + (name || '') + '(' + params.join(', ') + ') {');
+    paramCounts
         .sort(compareNumbers)
         .forEach(function (count, index) {
-          var signature = parameters[count];
+          var signature = tree[count];
           var args = [];
@@ -170,3 +305,3 @@ var statement = (index == 0) ? 'if' : 'else if';
           code.push('  }');
-          if (index == counts.length - 1) {
+          if (index == paramCounts.length - 1) {
             code.push('  else {');
@@ -182,15 +317,10 @@ code.push('    throw new TypeError(\'Wrong number of arguments\');'); // TODO: output the allowed numbers
     factory.push('(function (defs) {');
-    Object.keys(defs).forEach(function (type) {
-      defs[type].forEach(function
-          (def, index) {
-        factory.push('var ' + type + index + ' = defs[\'' + type + '\'][' + index + '];');
-      });
-    });
+    factory = factory.concat(defs.code('defs'));
     factory = factory.concat(code);
-    factory.push( '})');
+    factory.push('})');
 
     var fn = eval(factory.join('\n'))(defs);
 
-    // attach the original functions
-    fn.signatures = normalized;
+    // attach the signatures with sub-functions to the constructed function
+    fn.signatures = normalizeSignatures(structure); // normalized signatures
 
@@ -201,3 +331,3 @@ return fn;
   // data type tests
-  compose.tests = {
+  compose.types = {
     'null':     function (x) {return x === null},
@@ -215,5 +345,5 @@ 'boolean':  function (x) {return typeof x === 'boolean'},
   function getTest(type) {
-    var test = compose.tests[type];
+    var test = compose.types[type];
     if (!test) {
-      var matches = Object.keys(compose.tests)
+      var matches = Object.keys(compose.types)
           .filter(function (t) {
@@ -220,0 +350,0 @@ return t.toLowerCase() == type.toLowerCase();

function-composer.min.js

@@ -1,1 +0,1 @@
-(function(root,factory){if(typeof define==="function"&&define.amd){define([],factory)}else if(typeof exports==="object"){module.exports=factory()}else{root.compose=factory()}})(this,function(){"use strict";function compareTypes(a,b){return a==="Object"?1:b==="Object"?-1:0}function compareNumbers(a,b){return a>b}function compose(name,signatures){if(!signatures){signatures=name;name=null}var normalized={};var defs={signature:[],test:[],convert:[]};function addDef(fn,type){var index=defs[type].indexOf(fn);if(index==-1){index=defs[type].length;defs[type].push(fn)}return type+index}var argumentCount=0;var parameters={};Object.keys(signatures).forEach(function(signature){var fn=signatures[signature];var params=signature!==""?signature.split(",").map(function(param){return param.trim()}):[];var normSignature=params.join(",");normalized[normSignature]=fn;argumentCount=Math.max(argumentCount,params.length);var obj=parameters[params.length];if(!obj){obj=parameters[params.length]={signature:[],fn:null,types:{}}}while(params.length>0){var param=params.shift();if(!obj.types[param]){obj.types[param]={signature:obj.signature.concat(param),fn:null,types:{}}}obj=obj.types[param]}obj.fn=fn});function switchTypes(signature,args,prefix){var code=[];if(signature.fn!==null){var def=addDef(signature.fn,"signature");code.push(prefix+"return "+def+"("+args.join(", ")+"); // signature: "+signature.signature)}else{Object.keys(signature.types).sort(compareTypes).forEach(function(type){var arg="arg"+args.length;var def=addDef(getTest(type),"test")+"("+arg+")";code.push(prefix+"if ("+def+") { // type: "+type);code=code.concat(switchTypes(signature.types[type],args.concat(arg),prefix+"  "));code.push(prefix+"}")});var added={};compose.conversions.filter(function(conversion){return signature.types[conversion.to]&&!signature.types[conversion.from]}).forEach(function(conversion){if(!added[conversion.from]){added[conversion.from]=true;var arg="arg"+args.length;var test=addDef(getTest(conversion.from),"test")+"("+arg+")";var convert=addDef(conversion.convert,"convert")+"("+arg+")";code.push(prefix+"if ("+test+") { // type: "+conversion.from+", convert to "+conversion.to);code=code.concat(switchTypes(signature.types[conversion.to],args.concat(convert),prefix+"  "));code.push(prefix+"}")}})}return code}var args=[];for(var i=0;i<argumentCount;i++){args.push("arg"+i)}var code=[];var counts=Object.keys(parameters);code.push("return function "+(name||"")+"("+args.join(", ")+") {");counts.sort(compareNumbers).forEach(function(count,index){var signature=parameters[count];var args=[];var statement=index==0?"if":"else if";code.push("  "+statement+" (arguments.length == "+count+") {");code=code.concat(switchTypes(signature,args,"    "));code.push("  }");if(index==counts.length-1){code.push("  else {");code.push("    throw new TypeError('Wrong number of arguments');");code.push("  }")}});code.push("  throw new TypeError('Wrong function signature');");code.push("}");var factory=[];factory.push("(function (defs) {");Object.keys(defs).forEach(function(type){defs[type].forEach(function(def,index){factory.push("var "+type+index+" = defs['"+type+"']["+index+"];")})});factory=factory.concat(code);factory.push("})");var fn=eval(factory.join("\n"))(defs);fn.signatures=normalized;return fn}compose.tests={"null":function(x){return x===null},"boolean":function(x){return typeof x==="boolean"},number:function(x){return typeof x==="number"},string:function(x){return typeof x==="string"},"function":function(x){return typeof x==="function"},Array:function(x){return Array.isArray(x)},Date:function(x){return x instanceof Date},RegExp:function(x){return x instanceof RegExp},Object:function(x){return typeof x==="object"}};function getTest(type){var test=compose.tests[type];if(!test){var matches=Object.keys(compose.tests).filter(function(t){return t.toLowerCase()==type.toLowerCase()}).map(function(t){return'"'+t+'"'});throw new Error('Unknown type "'+type+'"'+(matches.length?". Did you mean "+matches.join(", or ")+"?":""))}return test}compose.conversions=[];return compose});
+!function(e,t){"function"==typeof define&&define.amd?define([],t):"object"==typeof exports?module.exports=t():e.compose=t()}(this,function(){"use strict";function compareTypes(e,t){return"*"===e?1:"*"===t?-1:"Object"===e?1:"Object"===t?-1:0}function compareNumbers(e,t){return e>t}function Defs(){}function Signature(e,t){this.params="string"==typeof e?""!==e?e.split(",").map(function(e){return e.trim()}):[]:e,this.fn=t}function splitSignatures(e){return Object.keys(e).map(function(t){var n=e[t];return new Signature(t,n)})}function normalizeSignatures(e){var t={};return e.map(function(e){var n=e.params.join(",");if(n in t)throw new Error('Error: signature "'+n+'" defined twice');t[n]=e.fn}),t}function splitTypes(e){var t=[];return e.forEach(function(e){e.params.forEach(function(e,n){t[n]||(t[n]=[]),-1==t[n].indexOf(e)&&t[n].push(e)})}),t}function createParamsTree(e){var t={};return e.forEach(function(e){var n=e.params.concat([]),r=t[n.length];for(r||(r=t[n.length]={signature:[],fn:null,types:{}});n.length>0;){var o=n.shift();r.types[o]||(r.types[o]={signature:r.signature.concat(o),fn:null,types:{}}),r=r.types[o]}r.fn=e.fn}),t}function compose(name,signatures){function switchTypes(e,t,n){var r=[];if(null!==e.fn){var o=defs.add(e.fn,"signature");r.push(n+"return "+o+"("+t.join(", ")+"); // signature: "+e.signature)}else{Object.keys(e.types).sort(compareTypes).forEach(function(o,s){var u,c,a="arg"+t.length,i=n+"  ";if("*"==o)u=s>0?"else {":"",c=s>0?"}":"",0==s&&(i=n);else{var f=defs.add(getTest(o),"test")+"("+a+")";u="if ("+f+") { // type: "+o,c="}"}u&&r.push(n+u),r=r.concat(switchTypes(e.types[o],t.concat(a),i)),c&&r.push(n+c)});var s={};compose.conversions.filter(function(t){return e.types[t.to]&&!e.types[t.from]}).forEach(function(o){if(!s[o.from]){s[o.from]=!0;var u="arg"+t.length,c=defs.add(getTest(o.from),"test")+"("+u+")",a=defs.add(o.convert,"convert")+"("+u+")";r.push(n+"if ("+c+") { // type: "+o.from+", convert to "+o.to),r=r.concat(switchTypes(e.types[o.to],t.concat(a),n+"  ")),r.push(n+"}")}})}return r}signatures||(signatures=name,name=null);for(var defs=new Defs,structure=splitSignatures(signatures),types=splitTypes(structure),params=[],i=0;i<types.length;i++)params.push("arg"+i);var code=[],tree=createParamsTree(structure),paramCounts=Object.keys(tree);code.push("return function "+(name||"")+"("+params.join(", ")+") {"),paramCounts.sort(compareNumbers).forEach(function(e,t){var n=tree[e],r=[],o=0==t?"if":"else if";code.push("  "+o+" (arguments.length == "+e+") {"),code=code.concat(switchTypes(n,r,"    ")),code.push("  }"),t==paramCounts.length-1&&(code.push("  else {"),code.push("    throw new TypeError('Wrong number of arguments');"),code.push("  }"))}),code.push("  throw new TypeError('Wrong function signature');"),code.push("}");var factory=[];factory.push("(function (defs) {"),factory=factory.concat(defs.code("defs")),factory=factory.concat(code),factory.push("})");var fn=eval(factory.join("\n"))(defs);return fn.signatures=normalizeSignatures(structure),fn}function getTest(e){var t=compose.types[e];if(!t){var n=Object.keys(compose.types).filter(function(t){return t.toLowerCase()==e.toLowerCase()}).map(function(e){return'"'+e+'"'});throw new Error('Unknown type "'+e+'"'+(n.length?". Did you mean "+n.join(", or ")+"?":""))}return t}return Defs.prototype.add=function(e,t){t=t||"fn",this[t]||(this[t]=[]);var n=this[t].indexOf(e);return-1==n&&(n=this[t].length,this[t].push(e)),t+n},Defs.prototype.code=function(e){var t=this,n=[];return e=e||"defs",Object.keys(this).forEach(function(r){var o=t[r];o.forEach(function(t,o){n.push("var "+r+o+" = "+e+"['"+r+"']["+o+"];")})}),n},compose.types={"null":function(e){return null===e},"boolean":function(e){return"boolean"==typeof e},number:function(e){return"number"==typeof e},string:function(e){return"string"==typeof e},"function":function(e){return"function"==typeof e},Array:function(e){return Array.isArray(e)},Date:function(e){return e instanceof Date},RegExp:function(e){return e instanceof RegExp},Object:function(e){return"object"==typeof e}},compose.conversions=[],compose});

HISTORY.md

 # History
 
 
+## 2014-11-05, version 0.3.0
+
+- Implemented support for anytype arguments (denoted with `*`).
+
+
 ## 2014-10-23, version 0.2.0
@@ -5,0 +10,0 @@

package.json

 {
   "name": "function-composer",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "Compose functions with multiple type signatures",
@@ -26,3 +26,3 @@ "author": "Jos de Jong <[e-mail]> (https://github.com/josdejong)",
   "scripts": {
-    "minify": "uglifyjs function-composer.js -o function-composer.min.js",
+    "minify": "uglifyjs function-composer.js -o function-composer.min.js -c -m",
     "test": "mocha test --recursive",
@@ -29,0 +29,0 @@ "coverage": "istanbul cover _mocha -- test --recursive; echo \"\nCoverage report is available at ./coverage/lcov-report/index.html\""

README.md

@@ -14,3 +14,3 @@ function-composer
 
-# Load
+## Load
 
@@ -22,3 +22,3 @@ Install via npm:
 
-# Usage
+## Usage
 
@@ -57,3 +57,3 @@ Example usage:
 
-# Performance
+## Performance
 
@@ -67,6 +67,8 @@ Type checking input arguments adds some overhead to a function. For very small
 
-# API
+## API
 
-## Construction
+### Construction
 
+A function is constructed as:
+
 ```js
@@ -77,6 +79,7 @@ compose(signatures: Object.<string, function>) : function
 
-## Properties
+### Properties
 
-- `compose.tests: Object`  
-  A map with type checking tests. Add custom types like:
+- `compose.types: Object`
+  A map with the object types as key and a type checking test as value.
+  Custom types can be added like:
 
@@ -88,3 +91,3 @@ ```js
 
-  compose.tests['Person'] = function (x) {
+  compose.types['Person'] = function (x) {
     return x instanceof Person;
@@ -107,7 +110,32 @@ };
 
+### Types
 
-# Roadmap
+function-composer has the following built-in types:
 
-## Version 1
+- `null`
+- `boolean`
+- `number`
+- `string`
+- `function`
+- `Array`
+- `Date`
+- `RegExp`
+- `Object`
+- `*` (anytype)
 
+
+### Output
+
+The functions generated with `compose({...})` have:
+
+- A `toString()` function which returns well readable code, giving insight in
+  what the function exactly does.
+- A property `signatures`, which holds a map with the (normalized)
+  signatures as key and the original sub-functions as value.
+
+
+## Roadmap
+
+### Version 1
+
 - Extend function signatures:
@@ -118,5 +146,8 @@ - Any type arguments like `'*, boolean'`
   - Multiple types per argument like `number | string, number'`
+- Detailed error messages.
 - Create a good benchmark, to get insight in the overhead.
+- Allow conversions not to be able to convert any input (for example string to
+  number is not always possible).
 
-## Version 2
+### Version 2
 
@@ -129,7 +160,13 @@ - Extend function signatures:
 
+## Test
 
-# Minify
+To test the library, run:
 
+    npm test
+
+
+## Minify
+
 To generate the minified version of the library, run:
 
     npm run minify

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Improved metrics

Total package byte prevSize

39380

increased by20.37%

Lines of code

770

increased by34.15%

Number of lines in readme file

164

increased by29.13%

Number of medium supply chain risk alerts

1

decreased by-50%

No dependency changes