30 lines
1 KiB
JavaScript
30 lines
1 KiB
JavaScript
import { Bool, Int } from "../primitives/symbols.js";
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import { lsType } from "../structures/list_common.js";
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import { fnType } from "../metacircular.js";
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import { assign, makeGeneric, unify } from "./generics.js";
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// a -> Int
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const a_to_Int = makeGeneric(a => fnType({in: a, out: Int}));
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// Bool -> Int
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const Bool_to_Int = makeGeneric(() => fnType({in: lsType(Bool), out: Int}));
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// should be: Bool -> Int
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console.log(unify(a_to_Int, Bool_to_Int));
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// (a -> a) -> b
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const fnType2 = makeGeneric((a,b) => fnType({in: fnType({in: a, out: a}), out: b}));
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// (Bool -> Bool) -> a
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const fnType3 = makeGeneric(a => fnType({in: fnType({in: Bool, out: Bool}), out: a}));
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// should be: (Bool -> Bool) -> a
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console.log(unify(fnType2, fnType3));
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// (a -> b) -> [a] -> [b]
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const mapFnType = makeGeneric((a,b) =>
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fnType({
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in: fnType({in: a, out: b}),
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out: fnType({in: lsType(a), out: lsType(b)}),
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}));
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// a -> a
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const idFnType = makeGeneric(a =>
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fnType({in: a, out: a}));
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// should be: [a] -> [a]
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console.log(assign(mapFnType, idFnType));
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