You could improve the usability of this library (or FP in PHP in general), by implementing 'string lambdas' such as those found in Oliver Steele's Functional.js

You could improve the usability of this library (or FP in PHP in general), by implementing 'string lambdas' such as those found in Oliver Steele's Functional.js[0], which was a clever, if controversial, workaround for Javascript's lack of a concise anonymous function syntax at the time. For example function($n) use ($partial) { return $partial($n - 1) + $partial($n - 2); could become 'partial(n - 1) + partial(n - 2)' Compiling the string lambda to a function can be memoized with the string itself as the key (as many regex implementations do with the regex text) so each is only ever compiled once. [0] http://osteele.com/sources/javascript/functional/ http://osteele.com/sources/javascript/functional/