


grammar::me::util(nGrammar operations and usagrammar::me::util(n)


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NAME
       grammar::me::util - AST utilities

SYNOPSIS
       package require Tcl  8.4

       package require grammar::me::util  ?0.1?

       ::grammar::me::util::ast2tree ast tree ?root?

       ::grammar::me::util::ast2etree ast mcmd tree ?root?

       mcmd lc location

       mcmd tok from ?to?

       ::grammar::me::util::tree2ast tree ?root?

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DESCRIPTION
       This  package  provides  a number of utility command for the conversion
       between the various representations of abstract syntax trees as  speci-
       fied in the document grammar::me_ast.

       ::grammar::me::util::ast2tree ast tree ?root?
              This  command  converts  an ast from value to object representa-
              tion. All nodes in the ast will be converted into nodes of  this
              tree, with the root of the AST a child of the node root. If this
              node is not explicitly specified the root of the tree  is  used.
              Existing  content  of tree is not touched, i.e.  neither removed
              nor changed, with the exception  of  the  specified  root  node,
              which will gain a new child.

       ::grammar::me::util::ast2etree ast mcmd tree ?root?
              This  command is like ::grammar::me::util::ast2tree, except that
              the result is in the extended object representation of the input
              AST.  The source of the extended information is the command pre-
              fix mcmd.  It has to understand two methods, lc, and  tok,  with
              the semantics specified below.

              mcmd lc location
                     Takes  the  location  of  a  token given as offset in the
                     input stream and return a 2-element list  containing  the
                     associated line number and column index, in this order.

              mcmd tok from ?to?
                     Takes  one  or two locations from and to as offset in the
                     input stream and returns a Tcl list containing the speci-
                     fied  part  of the input stream. Both location are inclu-
                     sive. If to is not specified it will default to the value
                     of from.



grammar_me                     0.1                              1





grammar::me::util(nGrammar operations and usagrammar::me::util(n)


                     Each  element  of  the returned list is a list containing
                     the token, its associated lexeme, the  line  number,  and
                     column index, in this order.

       Both  the  ensemble  command ::grammar::me::tcl provided by the package
       grammar::me::tcl and the objects command created by the package ::gram-
       mar::me::cpu fit the above specification.

       ::grammar::me::util::tree2ast tree ?root?
              This command converts an ast in (extended) object representation
              into a value and returns it.  If a root node  is  specified  the
              AST  is generated from that node downward. Otherwise the root of
              the tree object is used as the starting point.


BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will  undoubtedly  contain
       bugs and other problems.  Please report such in the category grammar_me
       of       the       Tcllib       SF       Trackers       [http://source-
       forge.net/tracker/?group_id=12883].   Please  also report any ideas for
       enhancements you may have for either package and/or documentation.

KEYWORDS
       abstract syntax tree, syntax tree, tree

CATEGORY
       Grammars and finite automata

COPYRIGHT
       Copyright (c) 2005 Andreas Kupries <andreas_kupries@users.sourceforge.net>



























grammar_me                     0.1                              2


