rtg2sig — generates a Stratego signature from a regular tree grammar (RTG)


rtg2sig [--module name] [-i file | --input file] [-o file | --output file] [-b] [-S | --silent] [--verbose level] [-k level | --keep level] [-h | -? | --help] [--about] [--version]


The rtg2sig utility is used to generates a Stratego signature from a regular tree grammar.


Module Options

--module name

Specifies that the module name of the resulting Stratego file should be name. If --module is not given, the output file name is used. If that is not known, the input file name is used.

Common Input/Output Options

-i file

The input term given by the file name file.

In the absence of the -i option, input will be read from stdin.

-o file

The output will be written to the file given by the file name file.

In the absence of the -o option, output will be written to stdout.


The output will be written in the binary (BAF) ATerm format.

ATerms in the BAF format require a lot less space than ones in the TAF format, but the Java ATerm library does not currently support baf ATerms. ATerms in the baf format is the preferred format of exchange between Stratego tools.

Common Debugging Options


See --version.

-h, -?, --help

Display usage information.

--keep int

Keep intermediate results produced by the internal stages in the pretty-printing process. This is only useful for debugging. A high value of int indicates increased eagerness for keeping intermediate results.

Default setting is 0, indicating that no intermediates will be kept.

-S, --silent

Silent execution. Same as --verbose 0.

--verbose int

Set verbosity level to numerical value int. The higher the number, the more information about pp-aterm's inner workings are printed.

Alternatively, int can be set to either of the following verbosity levels, given in increasing order of verbosity: emergency, alert, critical, error, warning, notice, info, debug, vomit.


Displays the tool name and version.


Consider the regular tree grammar given below (the exciting part about how we created this from an SDF definition can be gleaned from the example for sdf2rtg):

regular tree grammar
  start Exp
    Exp      -> Minus(Exp,Exp)
    Exp      -> Plus(Exp,Exp)
    Exp      -> Mod(Exp,Exp)
    Exp      -> Div(Exp,Exp)
    Exp      -> Mul(Exp,Exp)
    Exp      -> Int(IntConst)
    Exp      -> Var(Id)
    IntConst -> <string>
    Id       -> <string>

Provided that this this regular tree grammar is stored in the file Exp.rtg, it can be converted into a Stratego signature using rtg2sig, as follows:

$ rtg2sig -i Exp.rtg -o Exp.str

The resulting Stratego signature given below may be used directly by your Stratego programs by importing the Exp module.

module Exp
imports list-cons option
    Minus : Exp * Exp -> Exp
    Plus  : Exp * Exp -> Exp
    Mod   : Exp * Exp -> Exp
    Div   : Exp * Exp -> Exp
    Mul   : Exp * Exp -> Exp
    Int   : IntConst -> Exp
    Var   : Id -> Exp
          : String -> IntConst
          : String -> Id

Reporting Bugs

Please report bugs to


Copyright (C) 2002-2005 Eelco Visser

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.