jeremykohn/functional-javascript

Automatically exported from code.google.com/p/functional-javascript

functional-javascript's Issues

Map (and other lib functions) parameter order

map takes three arguments... iterator, sequence, object


but in functional programming we want to call our functions with the data last.

in this case sequence is our data, so why not place object before sequence?

Original issue reported on code.google.com by [email protected] on 16 Jul 2014 at 8:35

"Function.S" should be "Functional.S"

What version of the product are you using? On what operating system?

 -- This is the version on osteele.com as of this morning.

Please provide any additional information below.

 ...just like I and K are in Functional. But at least the docs and the code
are consistent....  (-:

Original issue reported on code.google.com by [email protected] on 2 Nov 2007 at 6:13

'apply' used unnecessarily when 'call' can be used

In many of the functions, the 'apply' function is used and has an explicit 
array passed as the second argument, like this snippet from 'foldr':

result = fn.apply(object, [sequence[i], result]);

There is no reason to use 'apply' here - you should use 'call' when you know 
how many arguments you're passing ahead of time.  Lines like the above should 
instead be:

result = fn.call(object, sequence[i], result);

'call' is much faster than 'apply', and clearer.

Original issue reported on code.google.com by [email protected] on 27 Dec 2011 at 11:16

currying is broken: map('1-foobar', [2, 3]) = [-1, -2]

At the demo page

http://osteele.com/sources/javascript/functional/

enter 

map('1-foobar', [2, 3]) 

and the result is 

[-1, -2]

I am not sure if this is a defect of only the demo page, or the library
itself. 

Assuming there is no easy fix to the demo page, I would say currying is
broken.  The simplest thing would be to disallow currying, and only allow
constructions like 

map (function (a) {return a + 1;}, [2,3]);

Otherwise you have to fix currying to do something sane.

This was pointed out to me by rhoomba at 

http://programming.reddit.com/info/2u5tz/comments/c2u8ln

Original issue reported on code.google.com by [email protected] on 27 Sep 2007 at 9:22

Help understanding compose

Hi,

I'm obsessed with this library.  It's been a joy to use and has revolutionized 
the way i write code.  Seriously.

I know it may not translate very well, but I would love to try and recreate 
this point-free example from the tacit programming wikipedia 
(http://en.wikipedia.org/wiki/Tacit_programming):

// pointfree
mf = (. map) . (.) . filter 

// pointfull
mf criteria operator list = filter criteria (map operator list)


Is there a way this is possible?

Original issue reported on code.google.com by [email protected] on 19 Mar 2012 at 3:30

Eliminate dependency on browser DOM

What steps will reproduce the problem?

1. execute load('functional.js') from within Rhino

What is the expected output? What do you see instead?

I expect no output, no exceptions. But instead, we get an exception because
the "window" global is not defined.

Changing the top of the source to read:

var window;
var Functional = (window && window.Functional) || {};

Fixes the problem.

Original issue reported on code.google.com by [email protected] on 13 Sep 2007 at 2:50

Math with leading zeroes

What steps will reproduce the problem?
1.  from: http://osteele.com/sources/javascript/functional/  
change example box: map('10+', [2, 32])  this works fine, but map('10+', [2, 
032]) does not.  

What is the expected output? What do you see instead?
should see 42 for the second value, it returns 36 when using a leading zero.  I 
tested using a single digit value and it returned the correct values for all 
leading zero cases (from single to many), but once I used a 2 (or more) digit 
number, it began to exhibit the anomoly.

What version of the product are you using? On what operating system?
The one in the example above.  Chrome 19.0.1084.46 m, Win 7 (64bit).

Please provide any additional information below.

Original issue reported on code.google.com by [email protected] on 21 May 2012 at 6:28

Suggestion: Caching Lambda Functions

An application which calls Functional methods with lambda strings, rather
than verbosely-declared functions, will result in a lot of calls to
`string.lambda()`. However, at present each call to `lambda()` represents
an invocation of the javascript runtime compiler, whether or not the string
has been converted into a function already in a previous call.

I suggest caching the output of `string.lambda()` for equivalent inputs,
thereby (hopefully) improving performance by minimizing recompilation. A
modified version of `String.prototype.lambda`, including a small caching
facility, is attached.

Original issue reported on code.google.com by [email protected] on 7 Aug 2007 at 6:02

Attachments:

• String.prototype.lambda.js

toFunction does not work in Rhino

What steps will reproduce the problem?
1. Start Rhino Console
2. load("env.js","functional.js"); <-- env.js is DOM curtain for Rhino
3. ">2".toFunction();

What is the expected output? What do you see instead?

js: "functional.js#886(Function)", line 1: uncaught JavaScript runtime
exception: SyntaxError: missing formal parameter
js: function anonymous(['$1']) {return ($1>2)}
js: ...................^

Expected:
"function anonymous($1) {
    return $1 > 2;
}"



What version of the product are you using? On what operating system?
OS X, JVM 1.5, functional.js version: 1.0.1


Please provide any additional information below.

String.toFunction returns

function () {
    return this;
}


And String.prototype.toFunction returns
function () {
    var body = this;
    if (body.match(/\breturn\b/)) {
        return new Function(this);
    }
    return this.lambda();
}

which looks right.

This means the attached property toFunction() is used by Rhino instead of
the prototype chain.


It'd be great if this worked in rhino. javascript is fast becoming my
favourite language for scripting everything.

Original issue reported on code.google.com by [email protected] on 25 Sep 2007 at 2:15

Functional.zip doesn't work (fix included)

I can't find a mailinglist or anything, so I'm just adding this here (and 
private email)


commit 63b15fc9105e0df211e0b813314ff15d965559ea
Author: Randy Robertson <rmrobert <a|t> vmware __dot__ com>
Date:   Fri Apr 30 15:43:59 2010

    Fix usage of pluck

diff --git a/functional.min.js b/functional.min.js
index a0225f0..aeb7a89 100644
--- a/functional.min.js
+++ b/functional.min.js
@@ -34,7 +34,7 @@ Functional.invoke=function(methodName){var 
args=Array.slice(arguments,1);return
 Functional.pluck=function(name){return function(object){return 
object[name];}}
 Functional.until=function(pred,fn){fn=Function.toFunction(fn);pred=Functio
n.toFunction(pred);return function(value){while(!pred.call(null,value))
 value=fn.call(null,value);return value;}}
-Functional.zip=function(){var 
n=Math.min.apply(null,Functional.map('.length',arguments));var results=new 
Array(n);for(var i=0;i<n;i++){var 
key=String(i);results[key]=Functional.map(pluck(key),arguments);};return 
results;}
+Functional.zip=function(){var 
n=Math.min.apply(null,Functional.map('.length',arguments));var results=new 
Array(n);for(var i=0;i<n;i++){var 
key=String(i);results[key]=Functional.map(Functional.pluck(key),arguments);
};return r
 Functional._startRecordingMethodChanges=function(object){var 
initialMethods={};for(var name in object)
 initialMethods[name]=object[name];return{getChangedMethods:function(){var 
changedMethods={};for(var name in object)
 if(object[name]!=initialMethods[name])

Original issue reported on code.google.com by [email protected] on 3 May 2010 at 9:10

Add CommonJS conditional exports (Node.js compatibility)

The CommonJS module system defines an 'exports' object. Only values assigned as 
properties of this object return to the calling context (the caller and the 
called don't share a scope).

If you try to use Functional.js from a CommonJS-using system it won't work. I 
discovered this when trying to load Functinonal.js into my Node.js application.

Applying the following amendment to the Functional.js file would return the 
Functional and Function.prototype objects to the calling scope. The caller can 
then mix the Function.prototype object into Function.prototype in the calling 
scope.

>>
//
// CommonJS:
// Export Functional & Function if an exports object is detected.
//
if (typeof exports === 'object') {
  exports.Functional = Functional;
  exports.FunctionPrototype = Function.prototype;
}
<<

Functional.js is great by the way, Thanks a lot!

Dom

Original issue reported on code.google.com by [email protected] on 11 Oct 2010 at 2:37

Map should work on objects too

This library provides a lot of great stuff for lists, but next to nothing for 
objects.  But an object is not so different from a list.  They're both 
associative arrays, but when you iterate through an object you care what 
the key names are as well as the values.

I want to run map on an object like it's an associative array.  That is, I want 
to do something like python's iteritems()

What is the expected output? What do you see instead?

I expected to be able to do is this:

map('value key -> {key:key, value:value}', {a:"foo", b:5}) 
# -> [{key:"a", value:"foo"}, {key:"b", value:5}]

Unfortunately, this actually returns [undefined]

I think it should be made to work, though, because it already works for 
normal lists:

map('value key -> {key:key, value:value}', ["foo", 5]) 
# -> [{key:0, value:"foo"}, {key:0, value:5}]

Alternatively, if you want to preserve the counter functionality of the 
second argument, you could make the real key name be the third 
argument, like so:

map('value counter key -> {key:key, value:value}', {a:"foo", b:5}) 
# -> [{key:"a", value:"foo"}, {key:"b", value:5}]

What version of the product are you using? On what operating system?

1.0.2 in Safari 4 and Chrome 4 for Mac.

Please provide any additional information below.

The main reason I bring this up is, since your library doesn't contain any 
object iterators, I decided to include underscore.js in my project as well.  
Unfortunately, functional.js seems to break underscore.js -- when I include 
it, it kills the underscore identifier underscore.js uses.  You may file this 
as 
an additional bug.

I wanted to use underscore.js for its _.keys(object) and _.values(object) 
methods.  I proposed they add _.items(object) as well.  I suppose I could 
implement these myself though, since they're rather simple, but this does 
seem in the problem domain of this library.

Original issue reported on code.google.com by [email protected] on 19 Jan 2010 at 9:03

Interested in a Deep Map function?

Hey Oliver, Jeremy Ashkenas mentioned to me that this might be of interest to 
you for functional.js. What do you think? is this something you'd be interested 
in? (I've already written it)

would a map function like this be valuable?

{{{
// Used to map over fields in various parts of the object hierarchy
// all in one step. most useful when you receive an API response
// where all values are strings (but should be ints, dates, bools etc).
//
// Any value that ends with "[]" (ex. photo_ids[] - you know... like 
// an empty array index) indicates the value is an array and that it 
// should be iterated over.
//
// Example:

_.deepMap(obj, [
    "UserID",
    "profile.photos[].ID",
    "profile.lucky_numbers[]"
  ], function(val) {
    return parseInt(val);
});
}}}

The example takes something like

{{{
obj = {
  UserID: "15",
  profile: {
    photos: [
      {name: "dog", ID: "13"},
      {name: "cat", ID: "18"}
    ]
    lucky_numbers: ["15", "7", "21"]
  }
}
}}}

and gives you back:

{{{
obj = {
  UserID: 15,
  profile: {
    photos: [
      {name: "dog", ID: 13},
      {name: "cat", ID: 18}
    ]
    lucky_numbers: [15, 7, 21]
  }
}
}}}

I use it pretty often to convert the data in xml responses from an API to 
useful data types.

Original issue reported on code.google.com by [email protected] on 24 Nov 2010 at 5:03