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- import { decoderError } from "../../encoding/encodings";
- import { finished } from "../../encoding/finished";
- import { index, indexCodePointFor } from "../../encoding/indexes";
- import { end_of_stream } from "../../encoding/terminology";
- import { inRange } from "../../encoding/utilities";
- var states;
- (function (states) {
- states[states["ASCII"] = 0] = "ASCII";
- states[states["Roman"] = 1] = "Roman";
- states[states["Katakana"] = 2] = "Katakana";
- states[states["LeadByte"] = 3] = "LeadByte";
- states[states["TrailByte"] = 4] = "TrailByte";
- states[states["EscapeStart"] = 5] = "EscapeStart";
- states[states["Escape"] = 6] = "Escape";
- })(states || (states = {}));
- export class ISO2022JPDecoder {
- /**
- * @constructor
- * @implements {Decoder}
- * @param {{fatal: boolean}} options
- */
- constructor(options) {
- this.fatal = options.fatal;
- // iso-2022-jp's decoder has an associated iso-2022-jp decoder
- // state (initially ASCII), iso-2022-jp decoder output state
- // (initially ASCII), iso-2022-jp lead (initially 0x00), and
- // iso-2022-jp output flag (initially unset).
- /** @type {number} */ this.iso2022jp_decoder_state = states.ASCII,
- /** @type {number} */ this.iso2022jp_decoder_output_state = states.ASCII,
- /** @type {number} */ this.iso2022jp_lead = 0x00,
- /** @type {boolean} */ this.iso2022jp_output_flag = false;
- }
- /**
- * @param {Stream} stream The stream of bytes being decoded.
- * @param {number} bite The next byte read from the stream.
- * @return {?(number|!Array.<number>)} The next code point(s)
- * decoded, or null if not enough data exists in the input
- * stream to decode a complete code point.
- */
- handler(stream, bite) {
- // switching on iso-2022-jp decoder state:
- switch (this.iso2022jp_decoder_state) {
- default:
- case states.ASCII:
- // ASCII
- // Based on byte:
- // 0x1B
- if (bite === 0x1B) {
- // Set iso-2022-jp decoder state to escape start and return
- // continue.
- this.iso2022jp_decoder_state = states.EscapeStart;
- return null;
- }
- // 0x00 to 0x7F, excluding 0x0E, 0x0F, and 0x1B
- if (inRange(bite, 0x00, 0x7F) && bite !== 0x0E
- && bite !== 0x0F && bite !== 0x1B) {
- // Unset the iso-2022-jp output flag and return a code point
- // whose value is byte.
- this.iso2022jp_output_flag = false;
- return bite;
- }
- // end-of-stream
- if (bite === end_of_stream) {
- // Return finished.
- return finished;
- }
- // Otherwise
- // Unset the iso-2022-jp output flag and return error.
- this.iso2022jp_output_flag = false;
- return decoderError(this.fatal);
- case states.Roman:
- // Roman
- // Based on byte:
- // 0x1B
- if (bite === 0x1B) {
- // Set iso-2022-jp decoder state to escape start and return
- // continue.
- this.iso2022jp_decoder_state = states.EscapeStart;
- return null;
- }
- // 0x5C
- if (bite === 0x5C) {
- // Unset the iso-2022-jp output flag and return code point
- // U+00A5.
- this.iso2022jp_output_flag = false;
- return 0x00A5;
- }
- // 0x7E
- if (bite === 0x7E) {
- // Unset the iso-2022-jp output flag and return code point
- // U+203E.
- this.iso2022jp_output_flag = false;
- return 0x203E;
- }
- // 0x00 to 0x7F, excluding 0x0E, 0x0F, 0x1B, 0x5C, and 0x7E
- if (inRange(bite, 0x00, 0x7F) && bite !== 0x0E && bite !== 0x0F
- && bite !== 0x1B && bite !== 0x5C && bite !== 0x7E) {
- // Unset the iso-2022-jp output flag and return a code point
- // whose value is byte.
- this.iso2022jp_output_flag = false;
- return bite;
- }
- // end-of-stream
- if (bite === end_of_stream) {
- // Return finished.
- return finished;
- }
- // Otherwise
- // Unset the iso-2022-jp output flag and return error.
- this.iso2022jp_output_flag = false;
- return decoderError(this.fatal);
- case states.Katakana:
- // Katakana
- // Based on byte:
- // 0x1B
- if (bite === 0x1B) {
- // Set iso-2022-jp decoder state to escape start and return
- // continue.
- this.iso2022jp_decoder_state = states.EscapeStart;
- return null;
- }
- // 0x21 to 0x5F
- if (inRange(bite, 0x21, 0x5F)) {
- // Unset the iso-2022-jp output flag and return a code point
- // whose value is 0xFF61 − 0x21 + byte.
- this.iso2022jp_output_flag = false;
- return 0xFF61 - 0x21 + bite;
- }
- // end-of-stream
- if (bite === end_of_stream) {
- // Return finished.
- return finished;
- }
- // Otherwise
- // Unset the iso-2022-jp output flag and return error.
- this.iso2022jp_output_flag = false;
- return decoderError(this.fatal);
- case states.LeadByte:
- // Lead byte
- // Based on byte:
- // 0x1B
- if (bite === 0x1B) {
- // Set iso-2022-jp decoder state to escape start and return
- // continue.
- this.iso2022jp_decoder_state = states.EscapeStart;
- return null;
- }
- // 0x21 to 0x7E
- if (inRange(bite, 0x21, 0x7E)) {
- // Unset the iso-2022-jp output flag, set iso-2022-jp lead
- // to byte, iso-2022-jp decoder state to trail byte, and
- // return continue.
- this.iso2022jp_output_flag = false;
- this.iso2022jp_lead = bite;
- this.iso2022jp_decoder_state = states.TrailByte;
- return null;
- }
- // end-of-stream
- if (bite === end_of_stream) {
- // Return finished.
- return finished;
- }
- // Otherwise
- // Unset the iso-2022-jp output flag and return error.
- this.iso2022jp_output_flag = false;
- return decoderError(this.fatal);
- case states.TrailByte:
- // Trail byte
- // Based on byte:
- // 0x1B
- if (bite === 0x1B) {
- // Set iso-2022-jp decoder state to escape start and return
- // continue.
- this.iso2022jp_decoder_state = states.EscapeStart;
- return decoderError(this.fatal);
- }
- // 0x21 to 0x7E
- if (inRange(bite, 0x21, 0x7E)) {
- // 1. Set the iso-2022-jp decoder state to lead byte.
- this.iso2022jp_decoder_state = states.LeadByte;
- // 2. Let pointer be (iso-2022-jp lead − 0x21) × 94 + byte − 0x21.
- const pointer = (this.iso2022jp_lead - 0x21) * 94 + bite - 0x21;
- // 3. Let code point be the index code point for pointer in
- // index jis0208.
- const code_point = indexCodePointFor(pointer, index('jis0208'));
- // 4. If code point is null, return error.
- if (code_point === null)
- return decoderError(this.fatal);
- // 5. Return a code point whose value is code point.
- return code_point;
- }
- // end-of-stream
- if (bite === end_of_stream) {
- // Set the iso-2022-jp decoder state to lead byte, prepend
- // byte to stream, and return error.
- this.iso2022jp_decoder_state = states.LeadByte;
- stream.prepend(bite);
- return decoderError(this.fatal);
- }
- // Otherwise
- // Set iso-2022-jp decoder state to lead byte and return
- // error.
- this.iso2022jp_decoder_state = states.LeadByte;
- return decoderError(this.fatal);
- case states.EscapeStart:
- // Escape start
- // 1. If byte is either 0x24 or 0x28, set iso-2022-jp lead to
- // byte, iso-2022-jp decoder state to escape, and return
- // continue.
- if (bite === 0x24 || bite === 0x28) {
- this.iso2022jp_lead = bite;
- this.iso2022jp_decoder_state = states.Escape;
- return null;
- }
- // 2. Prepend byte to stream.
- stream.prepend(bite);
- // 3. Unset the iso-2022-jp output flag, set iso-2022-jp
- // decoder state to iso-2022-jp decoder output state, and
- // return error.
- this.iso2022jp_output_flag = false;
- this.iso2022jp_decoder_state = this.iso2022jp_decoder_output_state;
- return decoderError(this.fatal);
- case states.Escape:
- // Escape
- // 1. Let lead be iso-2022-jp lead and set iso-2022-jp lead to
- // 0x00.
- const lead = this.iso2022jp_lead;
- this.iso2022jp_lead = 0x00;
- // 2. Let state be null.
- let state = null;
- // 3. If lead is 0x28 and byte is 0x42, set state to ASCII.
- if (lead === 0x28 && bite === 0x42)
- state = states.ASCII;
- // 4. If lead is 0x28 and byte is 0x4A, set state to Roman.
- if (lead === 0x28 && bite === 0x4A)
- state = states.Roman;
- // 5. If lead is 0x28 and byte is 0x49, set state to Katakana.
- if (lead === 0x28 && bite === 0x49)
- state = states.Katakana;
- // 6. If lead is 0x24 and byte is either 0x40 or 0x42, set
- // state to lead byte.
- if (lead === 0x24 && (bite === 0x40 || bite === 0x42))
- state = states.LeadByte;
- // 7. If state is non-null, run these substeps:
- if (state !== null) {
- // 1. Set iso-2022-jp decoder state and iso-2022-jp decoder
- // output state to states.
- this.iso2022jp_decoder_state = this.iso2022jp_decoder_state = state;
- // 2. Let output flag be the iso-2022-jp output flag.
- const output_flag = this.iso2022jp_output_flag;
- // 3. Set the iso-2022-jp output flag.
- this.iso2022jp_output_flag = true;
- // 4. Return continue, if output flag is unset, and error
- // otherwise.
- return !output_flag ? null : decoderError(this.fatal);
- }
- // 8. Prepend lead and byte to stream.
- stream.prepend([lead, bite]);
- // 9. Unset the iso-2022-jp output flag, set iso-2022-jp
- // decoder state to iso-2022-jp decoder output state and
- // return error.
- this.iso2022jp_output_flag = false;
- this.iso2022jp_decoder_state = this.iso2022jp_decoder_output_state;
- return decoderError(this.fatal);
- }
- }
- }
- //# sourceMappingURL=ISO2022JPDecoder.js.map
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