functools.cache was newly added in version 3.9. The documentation states: Simple lightweight unbounded function cache. Sometimes called “memoize”. Returns the same as lru_cache(maxsize=None), creating a thin wrapper around a dictionary lookup for the function arguments. Because it never needs to evict old values, this is smaller and faster than lru_cache() with a size limit. Example … Read more
Every so often I see a question on SO which forces me to spend half an hour editing a really bad Wikipedia article. The article is now only moderately bad. In the part that bears on your question, I wrote as follows: In computer science, a function or expression is said to have a side … Read more
The Haskell Platform specifies mtl and transformers as standard. If you’re unsure, you should just use mtl. However, if you have a specific technical reason to look at the new libraries, they tend to address issues or add new features to mtl. monadLib in particular has some new features.
With respect to data structures, Chris Okasaki has done substantial research into adopting classic data structures into a purely functional setting, as many of the standard data structures no longer work when using destructive updates. His book “Purely Functional Data Structures” shows how some structures, like binomial heaps and red/black trees, can be implemented quite … Read more
There are cases where the same algorithm will optimize better in a pure context. Specifically, stream fusion allows an algorithm that consists of a sequence of loops that may be of widely varying form: maps, filters, folds, unfolds, to be composed into a single loop. The equivalent optimization in a conventional imperative setting, with mutable … Read more
Either OCaml or Haskell would be a good choice. Why not check out the LLVM tutorials for each language? The LLVM tutorial for OCaml is here: http://llvm.org/docs/tutorial/OCamlLangImpl1.html Haskell has more momentum these days, but there are plenty of good parsing libraries for OCaml as well including the PEG parser generator Aurochs, Menhir, and the GLR … Read more
You should read this question: Javascript as a functional language There are lots of useful links, including: Use functional programming techniques to write elegant JavaScript The Little JavaScripter Higher-Order JavaScript Eloquent JavaScript, Chapter 6: Functional Programming Now, for my opinion. A lot of people misunderstand JavaScript, possibly because its syntax looks like most other programming … Read more
No, they’re not the same, although they do both result in a function you can call via the symbol foo. One is a function declaration, the other is a function expression. They are evaluated at different times, have different effects on the scope in which they’re defined, and are legal in different places. Quoting my … Read more
Answer derived from this blog article: So my question is what would a more traditional functional approach to parsing (i.e. few side effects) look like? Sounds like you need to separate functional (as in Lisp, Scheme, Standard ML, CAML, OCaml, F#) from purity (absence of side effects, as in Haskell) and incidental language features (algebraic … Read more
Docstrings are stored as metadata under the :doc key. This is probably the number 1 most apparent use of metadata. Return and parameter types can be optionally tagged with metadata to improve performance by avoiding the overhead of reflecting on the types at runtime. These are also known as “type hints.” #^String is a type … Read more