\documentclass{article}
\usepackage{axiom}
\begin{document}
\title{\$SPAD/src/interp ptrop.boot}
\author{The Axiom Team}
\maketitle
\begin{abstract}
\end{abstract}
\eject
\tableofcontents
\eject
\section{License}
<<license>>=
-- Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are
-- met:
--
--     - Redistributions of source code must retain the above copyright
--       notice, this list of conditions and the following disclaimer.
--
--     - Redistributions in binary form must reproduce the above copyright
--       notice, this list of conditions and the following disclaimer in
--       the documentation and/or other materials provided with the
--       distribution.
--
--     - Neither the name of The Numerical ALgorithms Group Ltd. nor the
--       names of its contributors may be used to endorse or promote products
--       derived from this software without specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
-- IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
-- PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
-- OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-- PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@
<<*>>=
<<license>>

)package "BOOT"

--% Utility operations on Abstract Syntax Trees
 
-- An S-expression which people can read.
pfSexpr pform ==
    strip pform where
         strip pform ==
            pfId? pform       => pfIdSymbol pform
            pfLiteral?  pform => pfLiteralString pform
            pfLeaf? pform     => tokPart pform
 
            pfApplication? pform =>
                args :=
                    a := pfApplicationArg pform
                    if pfTuple? a then pf0TupleParts a else [a]
                [strip p for p in cons(pfApplicationOp pform, args)]
 
            cons(pfAbSynOp pform, [strip p for p in pfParts pform])
 
pfCopyWithPos( pform , pos ) == 
    pfLeaf? pform =>         pfLeaf( pfAbSynOp pform , tokPart pform , pos )
    pfTree( pfAbSynOp pform , [ pfCopyWithPos( p , pos ) for p in pfParts pform ] )
 
pfMapParts(f, pform) ==
    pfLeaf? pform => pform
    parts0 := pfParts pform
    parts1 := [FUNCALL(f, p) for p in parts0]
    -- Return the original if no changes.
    same := true
    for p0 in parts0 for p1 in parts1 while same repeat same := EQ(p0,p1)
    same => pform
    pfTree(pfAbSynOp pform, parts1)
 
 
pf0ApplicationArgs pform ==
    arg := pfApplicationArg pform
    pf0FlattenSyntacticTuple arg
 
pf0FlattenSyntacticTuple pform ==
    not pfTuple? pform => [pform]
    [:pf0FlattenSyntacticTuple p for p in pf0TupleParts pform]
 

@
\eject
\begin{thebibliography}{99}
\bibitem{1} nothing
\end{thebibliography}
\end{document}