Type Classes
Why Are PureScript's Type Classes So Granular?
See Phil's explanation of Counterexamples of Type Classes
Relationships
This SVG file (WIP, but still helpful) shows the relationships between the type classes (inheritance hierarchy, dual relationships, usage frequency, and package location) throughout the ecosystem:
Functions
There is also an Excel file (Type-Class-Functions.xlsx) that documents the functions of said type classes using a chart like so (Note: the following chart is long-vertically and short-horizontally to reduce horizontal scrolling. In the real chart, this is inverted):
| Example1 | Example2 | |
|---|---|---|
| package (the 'purescript-' prefix is omitted, so 'prelude' is really 'purescript-prelude') | prelude | prelude |
| Type class name | Functor | Functor |
| Function Definition (Either defined in the initial type class (I) or dervied using that function (D)) | I | D |
| Alias symbol (If no symbol exists, then there is no alias) | <$> | $> |
| Alias infix direction & precedence ( direction is either left (L) or right (R)precedence is 1..9) | L 4 | L 4 |
| Type Parameter (what the type that follows the type class (e.g. Functor f)) | f | f |
| Function Name | map | voidLeft |
| Constraints (These usually appear in derived functions, but may also appear in initial functions) | Functor f | |
| Return type | f b | f b |
| Arg 1 | (a -> b) | f a |
| Arg 2 | f a | a |
| ... | ... | ... |
| Arg N | ... | ... |
Laws
TODO
Category Theory
- See Bortosz Mileski's
- (unofficial) PDF / Hard back of all his blog posts
- blogs
- videos
- Tom Leinster's Basic Category Theory (intended audience: people with "relatively little mathematics background)