57 lines
1.9 KiB
TypeScript
57 lines
1.9 KiB
TypeScript
import * as t from "@babel/types";
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import type {
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JavaScriptSemanticPrimitive,
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JavaScriptSemanticValue,
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} from "./javascriptSemanticIr.js";
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import { compareCodePoints } from "../canonicalOrdering.js";
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import { semanticPrimitiveKey } from "./javascriptSemanticProvenance.js";
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/** Normalize one bounded collection of possible primitive values. */
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export const semanticPrimitiveSet = (
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values: readonly JavaScriptSemanticPrimitive[],
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): JavaScriptSemanticValue => {
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if (
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values.some((value) => typeof value === "number" && !Number.isFinite(value))
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)
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return {
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status: "unknown",
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reason: "Nonfinite numbers are outside the JSON primitive lattice.",
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};
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const unique = [
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...new Map(
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values.map((value) => [semanticPrimitiveKey(value), value]),
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).values(),
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].sort((left, right) =>
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compareCodePoints(semanticPrimitiveKey(left), semanticPrimitiveKey(right)),
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);
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const only = unique[0];
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return unique.length === 1 && only !== undefined
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? { status: "literal", value: only }
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: { status: "union", values: unique };
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};
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/** Read the primitive candidates retained in one lattice value. */
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export const semanticPrimitiveCandidates = (
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value: JavaScriptSemanticValue,
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): readonly JavaScriptSemanticPrimitive[] | null =>
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value.status === "literal"
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? [value.value]
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: value.status === "union"
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? value.values
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: null;
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/** Parse one Babel primitive literal without evaluating code. */
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export const semanticPrimitiveValue = (
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node: t.Node,
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):
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| { readonly found: true; readonly value: JavaScriptSemanticPrimitive }
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| { readonly found: false } => {
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if (t.isStringLiteral(node)) return { found: true, value: node.value };
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if (t.isNumericLiteral(node) && Number.isFinite(node.value))
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return { found: true, value: node.value };
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if (t.isBooleanLiteral(node)) return { found: true, value: node.value };
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if (t.isNullLiteral(node)) return { found: true, value: null };
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return { found: false };
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};
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