mirror of
https://github.com/HigherOrderCO/Kind.git
synced 2024-09-11 16:25:54 +03:00
Now, there are two local binders: let x = ... use x = ... The 'let' binder will create a local definition, type-check it, and assign a name to it. When compiled, it will create 'dup' nodes. The 'use' binder is just an alias. It will not bind a new variable, and, when compiled, will create inline copies. Also, for type-checking, it allows creating aliases that are definitionaly equal for the checker.
13 lines
353 B
Plaintext
13 lines
353 B
Plaintext
List.find
|
|
: ∀(A: *) ∀(cond: ∀(x: A) Bool) ∀(list: (List A))
|
|
(Maybe A)
|
|
= λA λcond λlist
|
|
use P = λx (Maybe A)
|
|
use cons = λhead λtail
|
|
use found = (cond head)
|
|
use P = λx (Maybe A)
|
|
use true = (Maybe.some A head)
|
|
use false = (List.find A cond tail)
|
|
(~found P true false)
|
|
use nil = (Maybe.none A)
|
|
(~list P cons nil) |