Skip to content

Instantly share code, notes, and snippets.

@chrisdone
chrisdone / AnIntro.md
Last active Aug 21, 2020
Statically Typed Lisp
View AnIntro.md

Basic unit type:

λ> replTy "()"
() :: ()

Basic functions:

@pchiusano
pchiusano / type-inhabitants.markdown
Last active Jan 21, 2020
Reasoning about type inhabitants in Haskell
View type-inhabitants.markdown

This is material to go along with a 2014 Boston Haskell talk.

We are going to look at a series of type signatures in Haskell and explore how parametricity (or lack thereof) lets us constrain what a function is allowed to do.

Let's start with a decidedly non-generic function signature. What are the possible implementations of this function which typecheck?

wrangle :: Int -> Int
View Remove all git tags
#Delete local tags.
git tag -l | xargs git tag -d
#Fetch remote tags.
git fetch
#Delete remote tags.
git tag -l | xargs -n 1 git push --delete origin
#Delete local tasg.
git tag -l | xargs git tag -d
@chaitanyagupta
chaitanyagupta / _reader-macros.md
Last active Oct 19, 2020
Reader Macros in Common Lisp
View _reader-macros.md

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

You can’t perform that action at this time.