docs: genericClosure

This commit is contained in:
Tom Bereknyei 2022-03-23 22:54:43 -04:00
parent 8ad485ea89
commit 0736f3651d

View file

@ -694,7 +694,32 @@ static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * ar
static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info { static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info {
.name = "__genericClosure", .name = "__genericClosure",
.args = {"attrset"},
.arity = 1, .arity = 1,
.doc = R"(
Take an *attrset* with values named `startSet` and `operator` in order to
return a *list of attrsets* by starting with the `startSet`, recursively
applying the `operator` function to each element. The *attrsets* in the
`startSet` and produced by the `operator` must each contain value named
`key` which are comparable to each other. The result is produced by
repeatedly calling the operator for each element encountered with a
unique key, terminating when no new elements are produced. For example,
```
builtins.genericClosure {
startSet = [ {key = 5;} ];
operator = item: [{
key = if (item.key / 2 ) * 2 == item.key
then item.key / 2
else 3 * item.key + 1;
}];
}
```
evaluates to
```
[ { key = 5; } { key = 16; } { key = 8; } { key = 4; } { key = 2; } { key = 1; } ]
```
)",
.fun = prim_genericClosure, .fun = prim_genericClosure,
}); });