Functional languages are based on lambda calculus and the CS literature often uses examples where a lambda expression is called simply, "lambda."
In JavaScript, one common use of lambdas is when you register a callback function with some asynchronous operation like an ajax request. Another is for operations on collections of objects like visiting every item in an array.
I wondered if one could use the lambda character, λ, as a variable name in javascript. It would be more compact (one character instead of
See it run here.
Notice that the character encoding is set to UTF-16. If you don't do this you'll get errors. Since the encoding is set that way, I don't even use html entities like λ to write λ :)
Note: I haven't tried this in any version of IE but it appears to work in Chrome, Safari and Firefox.
Now, how do you actually type λ into a text editor? That took some digging. Here's what I did on OSX:
- Open System Preferences -> Language and Text -> Input Sources
- Scroll down to "Unicode Hex Input" and make sure that checkbox is checked.
- Open the US Flag (or nationality of your locale :) icon in the upper right of the OSX menu bar and switch to "Unicode Hex Input" (the "U+" icon)
- Now whenever I want a λ I can just hold down the Option key while I type 03bb and blammo I get a λ. Which by the way is still five key presses but looks way cooler than "lambda" and takes up less space on the screen.
I have no idea what you have to do on linux or windows.
You're right, this isn't very practical. And setting your encoding from UTF-8 to UTF-16 like, doubles the bytes you have to transmit. But you ARE gzipping all of your http responses aren't you? AREN'T YOU?