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-- Copyright (C) 2007-2008, Gabriel Dos Reis.
-- 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.
-- This file contains a low-level code for parsing a Spad source file
-- into an internal AST. Please note that this AST is the AST used by
-- the Spad compiler, which is different from the AST used by the
-- interpreter (a VAT). The AST, for the entire file, is a List Syntax
-- Since this is low-level code, I don't expect people to get here,
-- and you should directly use it. If you think, you need to get to
-- here, then something is already wrong.
-- There is a higher-level interface, written in SPAD, to this
-- code. See the algebra file spad-parser.spad.
--
-- -- gdr/2007-11-02
--
import metalex
import parse
namespace BOOT
++ Given a pathname to a source file containing Spad code, returns
++ a list of (old) AST objects representing the toplevel expressions
++ in that file.
++ ??? system commands are still executed even if they may not be
++ ??? meaningful. Eventually this code will go away when we
++ ??? finally use the new parser everwhere.
parseSpadFile sourceFile ==
$SPAD := true -- we are parsing Spad,
$BOOT := false -- not Boot.
SETQ(_*EOF_*, false) -- end of current input?
FILE_-CLOSED : local := false -- current stream closed?
$OutputStream := MAKE_-SYNONYM_-STREAM "*STANDARD-OUTPUT*" -- noise to standard output
-- we need to tell the post-parsing transformers that we're compiling
-- Spad because few parse forms have slightly different representations
-- depending on whether we are interpreter mode or compiler mode.
savedInteractiveMode := $InteractiveMode
$InteractiveMode := false
INIT_-BOOT_/SPAD_-READER()
-- we need to restore the global input stream state after we
-- finished messing with it.
savedInStream := (IN_-STREAM : local)
-- If soureFile cannot be processed for whatever reasons
-- get out of here instead of being stuck later.
not (IN_-STREAM := MAKE_-INSTREAM sourceFile) =>
$InteractiveMode := savedInteractiveMode
IN_-STREAM := savedInStream
systemError '"cannot open input source file"
INITIALIZE_-PREPARSE IN_-STREAM
-- gather parse trees for all toplevel expressions in sourceFile.
asts := []
while ^(_*EOF_* or FILE_-CLOSED) repeat
BOOT_-LINE_-STACK : local := PREPARSE IN_-STREAM
LINE : local := CDAR BOOT_-LINE_-STACK
PARSE_-NewExpr()
asts := [parseTransform postTransform POP_-STACK_-1(), :asts]
-- clean up the mess, and get out of here
IOCLEAR(IN_-STREAM, OUT_-STREAM)
SHUT IN_-STREAM
IN_-STREAM := savedInStream
$InteractiveMode := savedInteractiveMode
-- we accumulated the parse trees in reverse order
nreverse asts
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