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 specified in the document grammar::me_ast.

       ::grammar::me::util::ast2tree ast tree ?root?
              This command converts an ast from value to object representation. 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
              prefix 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  specified  part of the input stream. Both location are inclusive. If to is
                     not specified it will default to the value of from.

                     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 ::grammar::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 Trackers [http://core.tcl.tk/tcllib/reportlist].
       Please also report any ideas for enhancements you may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments  can  be  made  by
       going  to the Edit form of the ticket immediately after its creation, and then using the left-most button
       in the secondary navigation bar.

KEYWORDS

       abstract syntax tree, syntax tree, tree

CATEGORY

       Grammars and finite automata

COPYRIGHT

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

tcllib                                                 0.1                               grammar::me::util(3tcl)