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Merge pull request #6305 from flox/genericClosure_doc
docs: genericClosure
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d67fe90375
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@ -694,7 +694,32 @@ static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * ar
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static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info {
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static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info {
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.name = "__genericClosure",
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.name = "__genericClosure",
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.args = {"attrset"},
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.arity = 1,
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.arity = 1,
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.doc = R"(
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Take an *attrset* with values named `startSet` and `operator` in order to
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return a *list of attrsets* by starting with the `startSet`, recursively
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applying the `operator` function to each element. The *attrsets* in the
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`startSet` and produced by the `operator` must each contain value named
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`key` which are comparable to each other. The result is produced by
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repeatedly calling the operator for each element encountered with a
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unique key, terminating when no new elements are produced. For example,
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```
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builtins.genericClosure {
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startSet = [ {key = 5;} ];
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operator = item: [{
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key = if (item.key / 2 ) * 2 == item.key
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then item.key / 2
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else 3 * item.key + 1;
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}];
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}
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```
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evaluates to
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```
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[ { key = 5; } { key = 16; } { key = 8; } { key = 4; } { key = 2; } { key = 1; } ]
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```
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)",
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.fun = prim_genericClosure,
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.fun = prim_genericClosure,
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});
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});
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