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496 lines
19 KiB
496 lines
19 KiB
import htmlDecodeTree from "./generated/decode-data-html.js"; |
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import xmlDecodeTree from "./generated/decode-data-xml.js"; |
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import decodeCodePoint, { replaceCodePoint, fromCodePoint, } from "./decode_codepoint.js"; |
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// Re-export for use by eg. htmlparser2 |
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export { htmlDecodeTree, xmlDecodeTree, decodeCodePoint }; |
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export { replaceCodePoint, fromCodePoint } from "./decode_codepoint.js"; |
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var CharCodes; |
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(function (CharCodes) { |
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CharCodes[CharCodes["NUM"] = 35] = "NUM"; |
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CharCodes[CharCodes["SEMI"] = 59] = "SEMI"; |
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CharCodes[CharCodes["EQUALS"] = 61] = "EQUALS"; |
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CharCodes[CharCodes["ZERO"] = 48] = "ZERO"; |
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CharCodes[CharCodes["NINE"] = 57] = "NINE"; |
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CharCodes[CharCodes["LOWER_A"] = 97] = "LOWER_A"; |
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CharCodes[CharCodes["LOWER_F"] = 102] = "LOWER_F"; |
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CharCodes[CharCodes["LOWER_X"] = 120] = "LOWER_X"; |
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CharCodes[CharCodes["LOWER_Z"] = 122] = "LOWER_Z"; |
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CharCodes[CharCodes["UPPER_A"] = 65] = "UPPER_A"; |
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CharCodes[CharCodes["UPPER_F"] = 70] = "UPPER_F"; |
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CharCodes[CharCodes["UPPER_Z"] = 90] = "UPPER_Z"; |
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})(CharCodes || (CharCodes = {})); |
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/** Bit that needs to be set to convert an upper case ASCII character to lower case */ |
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const TO_LOWER_BIT = 0b100000; |
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export var BinTrieFlags; |
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(function (BinTrieFlags) { |
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BinTrieFlags[BinTrieFlags["VALUE_LENGTH"] = 49152] = "VALUE_LENGTH"; |
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BinTrieFlags[BinTrieFlags["BRANCH_LENGTH"] = 16256] = "BRANCH_LENGTH"; |
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BinTrieFlags[BinTrieFlags["JUMP_TABLE"] = 127] = "JUMP_TABLE"; |
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})(BinTrieFlags || (BinTrieFlags = {})); |
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function isNumber(code) { |
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return code >= CharCodes.ZERO && code <= CharCodes.NINE; |
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} |
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function isHexadecimalCharacter(code) { |
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return ((code >= CharCodes.UPPER_A && code <= CharCodes.UPPER_F) || |
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(code >= CharCodes.LOWER_A && code <= CharCodes.LOWER_F)); |
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} |
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function isAsciiAlphaNumeric(code) { |
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return ((code >= CharCodes.UPPER_A && code <= CharCodes.UPPER_Z) || |
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(code >= CharCodes.LOWER_A && code <= CharCodes.LOWER_Z) || |
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isNumber(code)); |
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} |
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/** |
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* Checks if the given character is a valid end character for an entity in an attribute. |
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* |
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* Attribute values that aren't terminated properly aren't parsed, and shouldn't lead to a parser error. |
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* See the example in https://html.spec.whatwg.org/multipage/parsing.html#named-character-reference-state |
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*/ |
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function isEntityInAttributeInvalidEnd(code) { |
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return code === CharCodes.EQUALS || isAsciiAlphaNumeric(code); |
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} |
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var EntityDecoderState; |
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(function (EntityDecoderState) { |
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EntityDecoderState[EntityDecoderState["EntityStart"] = 0] = "EntityStart"; |
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EntityDecoderState[EntityDecoderState["NumericStart"] = 1] = "NumericStart"; |
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EntityDecoderState[EntityDecoderState["NumericDecimal"] = 2] = "NumericDecimal"; |
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EntityDecoderState[EntityDecoderState["NumericHex"] = 3] = "NumericHex"; |
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EntityDecoderState[EntityDecoderState["NamedEntity"] = 4] = "NamedEntity"; |
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})(EntityDecoderState || (EntityDecoderState = {})); |
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export var DecodingMode; |
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(function (DecodingMode) { |
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/** Entities in text nodes that can end with any character. */ |
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DecodingMode[DecodingMode["Legacy"] = 0] = "Legacy"; |
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/** Only allow entities terminated with a semicolon. */ |
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DecodingMode[DecodingMode["Strict"] = 1] = "Strict"; |
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/** Entities in attributes have limitations on ending characters. */ |
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DecodingMode[DecodingMode["Attribute"] = 2] = "Attribute"; |
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})(DecodingMode || (DecodingMode = {})); |
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/** |
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* Token decoder with support of writing partial entities. |
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*/ |
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export class EntityDecoder { |
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constructor( |
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/** The tree used to decode entities. */ |
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decodeTree, |
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/** |
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* The function that is called when a codepoint is decoded. |
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* |
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* For multi-byte named entities, this will be called multiple times, |
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* with the second codepoint, and the same `consumed` value. |
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* |
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* @param codepoint The decoded codepoint. |
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* @param consumed The number of bytes consumed by the decoder. |
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*/ |
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emitCodePoint, |
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/** An object that is used to produce errors. */ |
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errors) { |
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this.decodeTree = decodeTree; |
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this.emitCodePoint = emitCodePoint; |
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this.errors = errors; |
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/** The current state of the decoder. */ |
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this.state = EntityDecoderState.EntityStart; |
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/** Characters that were consumed while parsing an entity. */ |
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this.consumed = 1; |
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/** |
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* The result of the entity. |
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* |
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* Either the result index of a numeric entity, or the codepoint of a |
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* numeric entity. |
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*/ |
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this.result = 0; |
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/** The current index in the decode tree. */ |
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this.treeIndex = 0; |
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/** The number of characters that were consumed in excess. */ |
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this.excess = 1; |
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/** The mode in which the decoder is operating. */ |
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this.decodeMode = DecodingMode.Strict; |
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} |
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/** Resets the instance to make it reusable. */ |
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startEntity(decodeMode) { |
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this.decodeMode = decodeMode; |
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this.state = EntityDecoderState.EntityStart; |
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this.result = 0; |
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this.treeIndex = 0; |
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this.excess = 1; |
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this.consumed = 1; |
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} |
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/** |
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* Write an entity to the decoder. This can be called multiple times with partial entities. |
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* If the entity is incomplete, the decoder will return -1. |
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* |
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* Mirrors the implementation of `getDecoder`, but with the ability to stop decoding if the |
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* entity is incomplete, and resume when the next string is written. |
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* |
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* @param string The string containing the entity (or a continuation of the entity). |
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* @param offset The offset at which the entity begins. Should be 0 if this is not the first call. |
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* @returns The number of characters that were consumed, or -1 if the entity is incomplete. |
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*/ |
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write(str, offset) { |
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switch (this.state) { |
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case EntityDecoderState.EntityStart: { |
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if (str.charCodeAt(offset) === CharCodes.NUM) { |
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this.state = EntityDecoderState.NumericStart; |
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this.consumed += 1; |
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return this.stateNumericStart(str, offset + 1); |
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} |
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this.state = EntityDecoderState.NamedEntity; |
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return this.stateNamedEntity(str, offset); |
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} |
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case EntityDecoderState.NumericStart: { |
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return this.stateNumericStart(str, offset); |
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} |
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case EntityDecoderState.NumericDecimal: { |
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return this.stateNumericDecimal(str, offset); |
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} |
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case EntityDecoderState.NumericHex: { |
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return this.stateNumericHex(str, offset); |
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} |
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case EntityDecoderState.NamedEntity: { |
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return this.stateNamedEntity(str, offset); |
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} |
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} |
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} |
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/** |
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* Switches between the numeric decimal and hexadecimal states. |
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* |
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* Equivalent to the `Numeric character reference state` in the HTML spec. |
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* |
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* @param str The string containing the entity (or a continuation of the entity). |
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* @param offset The current offset. |
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* @returns The number of characters that were consumed, or -1 if the entity is incomplete. |
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*/ |
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stateNumericStart(str, offset) { |
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if (offset >= str.length) { |
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return -1; |
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} |
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if ((str.charCodeAt(offset) | TO_LOWER_BIT) === CharCodes.LOWER_X) { |
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this.state = EntityDecoderState.NumericHex; |
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this.consumed += 1; |
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return this.stateNumericHex(str, offset + 1); |
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} |
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this.state = EntityDecoderState.NumericDecimal; |
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return this.stateNumericDecimal(str, offset); |
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} |
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addToNumericResult(str, start, end, base) { |
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if (start !== end) { |
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const digitCount = end - start; |
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this.result = |
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this.result * Math.pow(base, digitCount) + |
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parseInt(str.substr(start, digitCount), base); |
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this.consumed += digitCount; |
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} |
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} |
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/** |
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* Parses a hexadecimal numeric entity. |
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* |
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* Equivalent to the `Hexademical character reference state` in the HTML spec. |
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* |
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* @param str The string containing the entity (or a continuation of the entity). |
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* @param offset The current offset. |
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* @returns The number of characters that were consumed, or -1 if the entity is incomplete. |
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*/ |
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stateNumericHex(str, offset) { |
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const startIdx = offset; |
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while (offset < str.length) { |
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const char = str.charCodeAt(offset); |
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if (isNumber(char) || isHexadecimalCharacter(char)) { |
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offset += 1; |
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} |
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else { |
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this.addToNumericResult(str, startIdx, offset, 16); |
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return this.emitNumericEntity(char, 3); |
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} |
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} |
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this.addToNumericResult(str, startIdx, offset, 16); |
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return -1; |
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} |
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/** |
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* Parses a decimal numeric entity. |
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* |
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* Equivalent to the `Decimal character reference state` in the HTML spec. |
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* |
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* @param str The string containing the entity (or a continuation of the entity). |
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* @param offset The current offset. |
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* @returns The number of characters that were consumed, or -1 if the entity is incomplete. |
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*/ |
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stateNumericDecimal(str, offset) { |
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const startIdx = offset; |
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while (offset < str.length) { |
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const char = str.charCodeAt(offset); |
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if (isNumber(char)) { |
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offset += 1; |
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} |
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else { |
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this.addToNumericResult(str, startIdx, offset, 10); |
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return this.emitNumericEntity(char, 2); |
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} |
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} |
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this.addToNumericResult(str, startIdx, offset, 10); |
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return -1; |
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} |
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/** |
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* Validate and emit a numeric entity. |
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* |
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* Implements the logic from the `Hexademical character reference start |
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* state` and `Numeric character reference end state` in the HTML spec. |
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* |
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* @param lastCp The last code point of the entity. Used to see if the |
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* entity was terminated with a semicolon. |
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* @param expectedLength The minimum number of characters that should be |
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* consumed. Used to validate that at least one digit |
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* was consumed. |
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* @returns The number of characters that were consumed. |
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*/ |
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emitNumericEntity(lastCp, expectedLength) { |
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var _a; |
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// Ensure we consumed at least one digit. |
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if (this.consumed <= expectedLength) { |
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(_a = this.errors) === null || _a === void 0 ? void 0 : _a.absenceOfDigitsInNumericCharacterReference(this.consumed); |
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return 0; |
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} |
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// Figure out if this is a legit end of the entity |
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if (lastCp === CharCodes.SEMI) { |
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this.consumed += 1; |
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} |
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else if (this.decodeMode === DecodingMode.Strict) { |
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return 0; |
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} |
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this.emitCodePoint(replaceCodePoint(this.result), this.consumed); |
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if (this.errors) { |
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if (lastCp !== CharCodes.SEMI) { |
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this.errors.missingSemicolonAfterCharacterReference(); |
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} |
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this.errors.validateNumericCharacterReference(this.result); |
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} |
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return this.consumed; |
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} |
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/** |
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* Parses a named entity. |
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* |
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* Equivalent to the `Named character reference state` in the HTML spec. |
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* |
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* @param str The string containing the entity (or a continuation of the entity). |
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* @param offset The current offset. |
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* @returns The number of characters that were consumed, or -1 if the entity is incomplete. |
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*/ |
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stateNamedEntity(str, offset) { |
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const { decodeTree } = this; |
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let current = decodeTree[this.treeIndex]; |
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// The mask is the number of bytes of the value, including the current byte. |
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let valueLength = (current & BinTrieFlags.VALUE_LENGTH) >> 14; |
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for (; offset < str.length; offset++, this.excess++) { |
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const char = str.charCodeAt(offset); |
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this.treeIndex = determineBranch(decodeTree, current, this.treeIndex + Math.max(1, valueLength), char); |
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if (this.treeIndex < 0) { |
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return this.result === 0 || |
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// If we are parsing an attribute |
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(this.decodeMode === DecodingMode.Attribute && |
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// We shouldn't have consumed any characters after the entity, |
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(valueLength === 0 || |
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// And there should be no invalid characters. |
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isEntityInAttributeInvalidEnd(char))) |
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? 0 |
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: this.emitNotTerminatedNamedEntity(); |
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} |
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current = decodeTree[this.treeIndex]; |
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valueLength = (current & BinTrieFlags.VALUE_LENGTH) >> 14; |
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// If the branch is a value, store it and continue |
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if (valueLength !== 0) { |
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// If the entity is terminated by a semicolon, we are done. |
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if (char === CharCodes.SEMI) { |
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return this.emitNamedEntityData(this.treeIndex, valueLength, this.consumed + this.excess); |
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} |
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// If we encounter a non-terminated (legacy) entity while parsing strictly, then ignore it. |
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if (this.decodeMode !== DecodingMode.Strict) { |
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this.result = this.treeIndex; |
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this.consumed += this.excess; |
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this.excess = 0; |
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} |
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} |
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} |
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return -1; |
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} |
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/** |
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* Emit a named entity that was not terminated with a semicolon. |
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* |
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* @returns The number of characters consumed. |
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*/ |
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emitNotTerminatedNamedEntity() { |
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var _a; |
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const { result, decodeTree } = this; |
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const valueLength = (decodeTree[result] & BinTrieFlags.VALUE_LENGTH) >> 14; |
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this.emitNamedEntityData(result, valueLength, this.consumed); |
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(_a = this.errors) === null || _a === void 0 ? void 0 : _a.missingSemicolonAfterCharacterReference(); |
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return this.consumed; |
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} |
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/** |
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* Emit a named entity. |
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* |
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* @param result The index of the entity in the decode tree. |
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* @param valueLength The number of bytes in the entity. |
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* @param consumed The number of characters consumed. |
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* |
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* @returns The number of characters consumed. |
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*/ |
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emitNamedEntityData(result, valueLength, consumed) { |
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const { decodeTree } = this; |
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this.emitCodePoint(valueLength === 1 |
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? decodeTree[result] & ~BinTrieFlags.VALUE_LENGTH |
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: decodeTree[result + 1], consumed); |
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if (valueLength === 3) { |
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// For multi-byte values, we need to emit the second byte. |
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this.emitCodePoint(decodeTree[result + 2], consumed); |
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} |
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return consumed; |
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} |
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/** |
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* Signal to the parser that the end of the input was reached. |
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* |
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* Remaining data will be emitted and relevant errors will be produced. |
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* |
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* @returns The number of characters consumed. |
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*/ |
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end() { |
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var _a; |
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switch (this.state) { |
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case EntityDecoderState.NamedEntity: { |
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// Emit a named entity if we have one. |
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return this.result !== 0 && |
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(this.decodeMode !== DecodingMode.Attribute || |
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this.result === this.treeIndex) |
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? this.emitNotTerminatedNamedEntity() |
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: 0; |
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} |
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// Otherwise, emit a numeric entity if we have one. |
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case EntityDecoderState.NumericDecimal: { |
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return this.emitNumericEntity(0, 2); |
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} |
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case EntityDecoderState.NumericHex: { |
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return this.emitNumericEntity(0, 3); |
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} |
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case EntityDecoderState.NumericStart: { |
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(_a = this.errors) === null || _a === void 0 ? void 0 : _a.absenceOfDigitsInNumericCharacterReference(this.consumed); |
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return 0; |
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} |
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case EntityDecoderState.EntityStart: { |
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// Return 0 if we have no entity. |
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return 0; |
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} |
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} |
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} |
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} |
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/** |
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* Creates a function that decodes entities in a string. |
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* |
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* @param decodeTree The decode tree. |
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* @returns A function that decodes entities in a string. |
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*/ |
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function getDecoder(decodeTree) { |
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let ret = ""; |
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const decoder = new EntityDecoder(decodeTree, (str) => (ret += fromCodePoint(str))); |
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return function decodeWithTrie(str, decodeMode) { |
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let lastIndex = 0; |
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let offset = 0; |
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while ((offset = str.indexOf("&", offset)) >= 0) { |
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ret += str.slice(lastIndex, offset); |
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decoder.startEntity(decodeMode); |
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const len = decoder.write(str, |
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// Skip the "&" |
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offset + 1); |
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if (len < 0) { |
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lastIndex = offset + decoder.end(); |
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break; |
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} |
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lastIndex = offset + len; |
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// If `len` is 0, skip the current `&` and continue. |
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offset = len === 0 ? lastIndex + 1 : lastIndex; |
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} |
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const result = ret + str.slice(lastIndex); |
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// Make sure we don't keep a reference to the final string. |
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ret = ""; |
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return result; |
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}; |
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} |
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/** |
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* Determines the branch of the current node that is taken given the current |
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* character. This function is used to traverse the trie. |
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* |
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* @param decodeTree The trie. |
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* @param current The current node. |
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* @param nodeIdx The index right after the current node and its value. |
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* @param char The current character. |
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* @returns The index of the next node, or -1 if no branch is taken. |
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*/ |
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export function determineBranch(decodeTree, current, nodeIdx, char) { |
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const branchCount = (current & BinTrieFlags.BRANCH_LENGTH) >> 7; |
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const jumpOffset = current & BinTrieFlags.JUMP_TABLE; |
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// Case 1: Single branch encoded in jump offset |
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if (branchCount === 0) { |
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return jumpOffset !== 0 && char === jumpOffset ? nodeIdx : -1; |
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} |
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// Case 2: Multiple branches encoded in jump table |
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if (jumpOffset) { |
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const value = char - jumpOffset; |
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return value < 0 || value >= branchCount |
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? -1 |
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: decodeTree[nodeIdx + value] - 1; |
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} |
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// Case 3: Multiple branches encoded in dictionary |
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// Binary search for the character. |
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let lo = nodeIdx; |
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let hi = lo + branchCount - 1; |
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while (lo <= hi) { |
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const mid = (lo + hi) >>> 1; |
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const midVal = decodeTree[mid]; |
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if (midVal < char) { |
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lo = mid + 1; |
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} |
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else if (midVal > char) { |
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hi = mid - 1; |
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} |
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else { |
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return decodeTree[mid + branchCount]; |
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} |
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} |
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return -1; |
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} |
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const htmlDecoder = getDecoder(htmlDecodeTree); |
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const xmlDecoder = getDecoder(xmlDecodeTree); |
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/** |
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* Decodes an HTML string. |
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* |
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* @param str The string to decode. |
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* @param mode The decoding mode. |
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* @returns The decoded string. |
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*/ |
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export function decodeHTML(str, mode = DecodingMode.Legacy) { |
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return htmlDecoder(str, mode); |
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} |
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/** |
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* Decodes an HTML string in an attribute. |
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* |
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* @param str The string to decode. |
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* @returns The decoded string. |
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*/ |
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export function decodeHTMLAttribute(str) { |
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return htmlDecoder(str, DecodingMode.Attribute); |
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} |
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/** |
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* Decodes an HTML string, requiring all entities to be terminated by a semicolon. |
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* |
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* @param str The string to decode. |
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* @returns The decoded string. |
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*/ |
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export function decodeHTMLStrict(str) { |
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return htmlDecoder(str, DecodingMode.Strict); |
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} |
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/** |
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* Decodes an XML string, requiring all entities to be terminated by a semicolon. |
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* |
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* @param str The string to decode. |
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* @returns The decoded string. |
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*/ |
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export function decodeXML(str) { |
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return xmlDecoder(str, DecodingMode.Strict); |
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} |
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//# sourceMappingURL=decode.js.map
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