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/*---------------------------------------------------------------------------------------------
editSurvivalTracker.ts
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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*--------------------------------------------------------------------------------------------*/
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/*
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* Edit-survival math for agent-host file edits.
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*
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* Sister implementation of the chat extension's `EditSurvivalTracker`
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* (`extensions/copilot/src/platform/editSurvivalTracking/common/editSurvivalTracker.ts`).
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* The extension version operates on multi-range `StringEdit`s with a
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* live `TextModel`; here we only have whole-file snapshots and (when
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* the tool input is recognisable) the explicit text the AI wrote. The
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* whole-file path is the baseline; the chunked path uses asymmetric
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* "fraction of AI 4-grams still present in the file" scoring so an
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* edit's score doesn't decay as the file grows around it.
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*
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* Mostly carried over from the chat extension's version.
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*/
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/**
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* Computes a number between 0 and 1 that reflects how similar the two
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* texts are by counting how many 4-grams are shared between them.
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*/
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export function compute4GramTextSimilarity(text1: string, text2: string): number {
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const n = 4;
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