Initial commit

node_modules/fast-check/lib/arbitrary/_internals/mappers/IndexToMappedConstant.js

@@ -0,0 +1,71 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.indexToMappedConstantMapperFor = indexToMappedConstantMapperFor;
+exports.indexToMappedConstantUnmapperFor = indexToMappedConstantUnmapperFor;
+const globals_1 = require("../../../utils/globals");
+const safeObjectIs = Object.is;
+function buildDichotomyEntries(entries) {
+    let currentFrom = 0;
+    const dichotomyEntries = [];
+    for (const entry of entries) {
+        const from = currentFrom;
+        currentFrom = from + entry.num;
+        const to = currentFrom - 1;
+        dichotomyEntries.push({ from, to, entry });
+    }
+    return dichotomyEntries;
+}
+function findDichotomyEntry(dichotomyEntries, choiceIndex) {
+    let min = 0;
+    let max = dichotomyEntries.length;
+    while (max - min > 1) {
+        const mid = ~~((min + max) / 2);
+        if (choiceIndex < dichotomyEntries[mid].from) {
+            max = mid;
+        }
+        else {
+            min = mid;
+        }
+    }
+    return dichotomyEntries[min];
+}
+function indexToMappedConstantMapperFor(entries) {
+    const dichotomyEntries = buildDichotomyEntries(entries);
+    return function indexToMappedConstantMapper(choiceIndex) {
+        const dichotomyEntry = findDichotomyEntry(dichotomyEntries, choiceIndex);
+        return dichotomyEntry.entry.build(choiceIndex - dichotomyEntry.from);
+    };
+}
+function buildReverseMapping(entries) {
+    const reverseMapping = { mapping: new globals_1.Map(), negativeZeroIndex: undefined };
+    let choiceIndex = 0;
+    for (let entryIdx = 0; entryIdx !== entries.length; ++entryIdx) {
+        const entry = entries[entryIdx];
+        for (let idxInEntry = 0; idxInEntry !== entry.num; ++idxInEntry) {
+            const value = entry.build(idxInEntry);
+            if (value === 0 && 1 / value === globals_1.Number.NEGATIVE_INFINITY) {
+                reverseMapping.negativeZeroIndex = choiceIndex;
+            }
+            else {
+                (0, globals_1.safeMapSet)(reverseMapping.mapping, value, choiceIndex);
+            }
+            ++choiceIndex;
+        }
+    }
+    return reverseMapping;
+}
+function indexToMappedConstantUnmapperFor(entries) {
+    let reverseMapping = null;
+    return function indexToMappedConstantUnmapper(value) {
+        if (reverseMapping === null) {
+            reverseMapping = buildReverseMapping(entries);
+        }
+        const choiceIndex = safeObjectIs(value, -0)
+            ? reverseMapping.negativeZeroIndex
+            : (0, globals_1.safeMapGet)(reverseMapping.mapping, value);
+        if (choiceIndex === undefined) {
+            throw new globals_1.Error('Unknown value encountered cannot be built using this mapToConstant');
+        }
+        return choiceIndex;
+    };
+}