mirror of https://github.com/denoland/deno.git
46 lines
1.0 KiB
TypeScript
46 lines
1.0 KiB
TypeScript
// Ported from js-yaml v3.13.1:
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// https://github.com/nodeca/js-yaml/commit/665aadda42349dcae869f12040d9b10ef18d12da
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// Copyright 2011-2015 by Vitaly Puzrin. All rights reserved. MIT license.
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// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
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import { Type } from "../type.ts";
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function resolveYamlNull(data: string): boolean {
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const max = data.length;
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return (
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(max === 1 && data === "~") ||
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(max === 4 && (data === "null" || data === "Null" || data === "NULL"))
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);
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}
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function constructYamlNull(): null {
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return null;
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}
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function isNull(object: unknown): object is null {
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return object === null;
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}
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export const nil = new Type("tag:yaml.org,2002:null", {
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construct: constructYamlNull,
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defaultStyle: "lowercase",
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kind: "scalar",
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predicate: isNull,
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represent: {
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canonical(): string {
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return "~";
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},
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lowercase(): string {
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return "null";
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},
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uppercase(): string {
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return "NULL";
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},
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camelcase(): string {
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return "Null";
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},
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},
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resolve: resolveYamlNull,
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});
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