/** Convert the simple input to be java code; wrap in a class, * convert method with "public void", add decls. This shows how to insert * extra text into a stream of tokens and how to replace a token * with some text. Calling toString() on the TokenRewriteStream * in Main will print out the original input stream. * * Note that you can do the instructions in any order as the * rewrite instructions just get queued up and executed upon toString(). */ grammar T; options { language=Python; } program @init { start = self.input.LT(1) } : method+ { self.input.insertBefore(start,"public class Wrapper {\n") # note the reference to the last token matched for method: self.input.insertAfter($method.stop, "\n}\n") } ; method : m='method' ID '(' ')' body {self.input.replace($m, "public void");} ; body // decls is on body's local variable stack but is visible to // any rule that body calls such as stat. From other rules // it is referenced as $body::decls // From within rule body, you can use $decls shorthand scope { decls } @init { $body::decls = set() } : lcurly='{' stat* '}' { # dump declarations for all identifiers seen in statement list for it in $body::decls: self.input.insertAfter($lcurly, "\nint "+it+";") } ; stat: ID '=' expr ';' {$body::decls.add($ID.text);} // track left-hand-sides ; expr: mul ('+' mul)* ; mul : atom ('*' atom)* ; atom: ID | INT ; ID : ('a'..'z'|'A'..'Z')+ ; INT : ('0'..'9')+ ; WS : (' '|'\t'|'\n')+ {$channel=HIDDEN;} ;
