|  |  |  |  | const { inRange, encoderError, end_of_stream, finished, isASCIIByte, isASCIICodePoint } = require('../utils'); | 
					
						
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							|  |  |  |  | // 15.5 x-user-defined
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							|  |  |  |  | // 15.5.1 x-user-defined decoder
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							|  |  |  |  | /** | 
					
						
							|  |  |  |  |  * @implements {Decoder} | 
					
						
							|  |  |  |  |  */ | 
					
						
							|  |  |  |  | class XUserDefinedDecoder { | 
					
						
							|  |  |  |  |   /** | 
					
						
							|  |  |  |  |    * @param {Stream} stream The stream of bytes being decoded. | 
					
						
							|  |  |  |  |    * @param {number} bite The next byte read from the stream. | 
					
						
							|  |  |  |  |    */ | 
					
						
							|  |  |  |  |   handler(stream, bite) { | 
					
						
							|  |  |  |  |   // 1. If byte is end-of-stream, return finished.
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							|  |  |  |  |     if (bite === end_of_stream) | 
					
						
							|  |  |  |  |       return finished | 
					
						
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							|  |  |  |  |     // 2. If byte is an ASCII byte, return a code point whose value
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							|  |  |  |  |     // is byte.
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							|  |  |  |  |     if (isASCIIByte(bite)) | 
					
						
							|  |  |  |  |       return bite | 
					
						
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							|  |  |  |  |     // 3. Return a code point whose value is 0xF780 + byte − 0x80.
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							|  |  |  |  |     return 0xF780 + bite - 0x80 | 
					
						
							|  |  |  |  |   } | 
					
						
							|  |  |  |  | } | 
					
						
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							|  |  |  |  | // 15.5.2 x-user-defined encoder
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							|  |  |  |  | /** | 
					
						
							|  |  |  |  |  * @implements {Encoder} | 
					
						
							|  |  |  |  |  */ | 
					
						
							|  |  |  |  | class XUserDefinedEncoder { | 
					
						
							|  |  |  |  |   /** | 
					
						
							|  |  |  |  |    * @param {Stream} stream Input stream. | 
					
						
							|  |  |  |  |    * @param {number} code_point Next code point read from the stream. | 
					
						
							|  |  |  |  |    */ | 
					
						
							|  |  |  |  |   handler(stream, code_point) { | 
					
						
							|  |  |  |  |   // 1.If code point is end-of-stream, return finished.
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							|  |  |  |  |     if (code_point === end_of_stream) | 
					
						
							|  |  |  |  |       return finished | 
					
						
							|  |  |  |  | 
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							|  |  |  |  |     // 2. If code point is an ASCII code point, return a byte whose
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							|  |  |  |  |     // value is code point.
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							|  |  |  |  |     if (isASCIICodePoint(code_point)) | 
					
						
							|  |  |  |  |       return code_point | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  |     // 3. If code point is in the range U+F780 to U+F7FF, inclusive,
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							|  |  |  |  |     // return a byte whose value is code point − 0xF780 + 0x80.
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							|  |  |  |  |     if (inRange(code_point, 0xF780, 0xF7FF)) | 
					
						
							|  |  |  |  |       return code_point - 0xF780 + 0x80 | 
					
						
							|  |  |  |  | 
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							|  |  |  |  |     // 4. Return error with code point.
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							|  |  |  |  |     return encoderError(code_point) | 
					
						
							|  |  |  |  |   } | 
					
						
							|  |  |  |  | } | 
					
						
							|  |  |  |  | 
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							|  |  |  |  | module.exports.XUserDefinedDecoder = XUserDefinedDecoder | 
					
						
							|  |  |  |  | module.exports.XUserDefinedEncoder = XUserDefinedEncoder |