The following class save decompilation information about the source.
The following class save decompilation information about the source. Source information is returned from the parser as a String associated with function nodes and with the toplevel script. When saved in the constant pool of a class, this string will be UTF-8 encoded, and token values will occupy a single byte. Source is saved (mostly) as token numbers. The tokens saved pretty much correspond to the token stream of a 'canonical' representation of the input program, as directed by the parser. (There were a few cases where tokens could have been left out where decompiler could easily reconstruct them, but I left them in for clarity). (I also looked adding source collection to TokenStream instead, where I could have limited the changes to a few lines in getToken... but this wouldn't have saved any space in the resulting source representation, and would have meant that I'd have to duplicate parser logic in the decompiler to disambiguate situations where newlines are important.) The function decompile expands the tokens back into their string representations, using simple lookahead to correct spacing and indentation. Assignments are saved as two-token pairs (Token.ASSIGN, op). Number tokens are stored inline, as a NUMBER token, a character representing the type, and either 1 or 4 characters representing the bit-encoding of the number. String types NAME, STRING and OBJECT are currently stored as a token type, followed by a character giving the length of the string (assumed to be less than 2^16), followed by the characters of the string inlined into the source string. Changing this to some reference to to the string in the compiled class' constant pool would probably save a lot of space... but would require some method of deriving the final constant pool entry from information available at parse time.
Decompiler Class Documentation
示例#1
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		/// <summary>Transforms the tree into a lower-level IR suitable for codegen.</summary>
		/// <remarks>
		/// Transforms the tree into a lower-level IR suitable for codegen.
		/// Optionally generates the encoded source.
		/// </remarks>
		public ScriptNode TransformTree(AstRoot root)
		{
			currentScriptOrFn = root;
			this.inUseStrictDirective = root.IsInStrictMode();
			int sourceStartOffset = decompiler.GetCurrentOffset();
			ScriptNode script = (ScriptNode)Transform(root);
			int sourceEndOffset = decompiler.GetCurrentOffset();
			script.SetEncodedSourceBounds(sourceStartOffset, sourceEndOffset);
			if (compilerEnv.IsGeneratingSource())
			{
				script.SetEncodedSource(decompiler.GetEncodedSource());
			}
			decompiler = null;
			return script;
		}