2290 lines
87 KiB
Scheme
2290 lines
87 KiB
Scheme
;;;; -*-scheme-*-
|
||
;;; GNU Mes --- Maxwell Equations of Software
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||
;;; Copyright (C) 2001, 2003, 2006 Free Software Foundation, Inc.
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||
;;;
|
||
;;; This file is part of GNU Mes.
|
||
;;;
|
||
;;; GNU Mes is free software; you can redistribute it and/or modify it
|
||
;;; under the terms of the GNU General Public License as published by
|
||
;;; the Free Software Foundation; either version 3 of the License, or (at
|
||
;;; your option) any later version.
|
||
;;;
|
||
;;; GNU Mes is distributed in the hope that it will be useful, but
|
||
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
;;; GNU General Public License for more details.
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||
;;;
|
||
;;; You should have received a copy of the GNU General Public License
|
||
;;; along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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||
|
||
;;; Taken from GNU Guile
|
||
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||
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||
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||
;;; Portable implementation of syntax-case
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;;; Extracted from Chez Scheme Version 5.9f
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;;; Authors: R. Kent Dybvig, Oscar Waddell, Bob Hieb, Carl Bruggeman
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;;; Modified by Mikael Djurfeldt <djurfeldt@nada.kth.se> according
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;;; to the ChangeLog distributed in the same directory as this file:
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;;; 1997-08-19, 1997-09-03, 1997-09-10, 2000-08-13, 2000-08-24,
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;;; 2000-09-12, 2001-03-08
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||
;;; Copyright (c) 1992-1997 Cadence Research Systems
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||
;;; Permission to copy this software, in whole or in part, to use this
|
||
;;; software for any lawful purpose, and to redistribute this software
|
||
;;; is granted subject to the restriction that all copies made of this
|
||
;;; software must include this copyright notice in full. This software
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||
;;; is provided AS IS, with NO WARRANTY, EITHER EXPRESS OR IMPLIED,
|
||
;;; INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY
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||
;;; OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL THE
|
||
;;; AUTHORS BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES OF ANY
|
||
;;; NATURE WHATSOEVER.
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||
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||
;;; Before attempting to port this code to a new implementation of
|
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;;; Scheme, please read the notes below carefully.
|
||
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||
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||
;;; This file defines the syntax-case expander, sc-expand, and a set
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||
;;; of associated syntactic forms and procedures. Of these, the
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||
;;; following are documented in The Scheme Programming Language,
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;;; Second Edition (R. Kent Dybvig, Prentice Hall, 1996). Most are
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||
;;; also documented in the R4RS and draft R5RS.
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||
;;;
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;;; bound-identifier=?
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||
;;; datum->syntax-object
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;;; define-syntax
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||
;;; fluid-let-syntax
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;;; free-identifier=?
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||
;;; generate-temporaries
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||
;;; identifier?
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||
;;; identifier-syntax
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||
;;; let-syntax
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||
;;; letrec-syntax
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||
;;; syntax
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;;; syntax-case
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;;; syntax-object->datum
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;;; syntax-rules
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;;; with-syntax
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;;;
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;;; All standard Scheme syntactic forms are supported by the expander
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;;; or syntactic abstractions defined in this file. Only the R4RS
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||
;;; delay is omitted, since its expansion is implementation-dependent.
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||
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;;; The remaining exports are listed below:
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||
;;;
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;;; (sc-expand datum)
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||
;;; if datum represents a valid expression, sc-expand returns an
|
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;;; expanded version of datum in a core language that includes no
|
||
;;; syntactic abstractions. The core language includes begin,
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||
;;; define, if, lambda, letrec, quote, and set!.
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||
;;; (eval-when situations expr ...)
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||
;;; conditionally evaluates expr ... at compile-time or run-time
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||
;;; depending upon situations (see the Chez Scheme System Manual,
|
||
;;; Revision 3, for a complete description)
|
||
;;; (syntax-error object message)
|
||
;;; used to report errors found during expansion
|
||
;;; (install-global-transformer symbol value)
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||
;;; used by expanded code to install top-level syntactic abstractions
|
||
;;; (syntax-dispatch e p)
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||
;;; used by expanded code to handle syntax-case matching
|
||
|
||
;;; The following nonstandard procedures must be provided by the
|
||
;;; implementation for this code to run.
|
||
;;;
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||
;;; (void)
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||
;;; returns the implementation's cannonical "unspecified value". This
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||
;;; usually works: (define void (lambda () (if #f #f))).
|
||
;;;
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||
;;; (andmap proc list1 list2 ...)
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||
;;; returns true if proc returns true when applied to each element of list1
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||
;;; along with the corresponding elements of list2 ....
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||
;;; The following definition works but does no error checking:
|
||
;;;
|
||
;;; (define andmap
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||
;;; (lambda (f first . rest)
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||
;;; (or (null? first)
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||
;;; (if (null? rest)
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||
;;; (let andmap ((first first))
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||
;;; (let ((x (car first)) (first (cdr first)))
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||
;;; (if (null? first)
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||
;;; (f x)
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||
;;; (and (f x) (andmap first)))))
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||
;;; (let andmap ((first first) (rest rest))
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||
;;; (let ((x (car first))
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;;; (xr (map car rest))
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||
;;; (first (cdr first))
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||
;;; (rest (map cdr rest)))
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||
;;; (if (null? first)
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||
;;; (apply f (cons x xr))
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||
;;; (and (apply f (cons x xr)) (andmap first rest)))))))))
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||
;;;
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||
;;; The following nonstandard procedures must also be provided by the
|
||
;;; implementation for this code to run using the standard portable
|
||
;;; hooks and output constructors. They are not used by expanded code,
|
||
;;; and so need be present only at expansion time.
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||
;;;
|
||
;;; (eval x)
|
||
;;; where x is always in the form ("noexpand" expr).
|
||
;;; returns the value of expr. the "noexpand" flag is used to tell the
|
||
;;; evaluator/expander that no expansion is necessary, since expr has
|
||
;;; already been fully expanded to core forms.
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||
;;;
|
||
;;; eval will not be invoked during the loading of psyntax.pp. After
|
||
;;; psyntax.pp has been loaded, the expansion of any macro definition,
|
||
;;; whether local or global, will result in a call to eval. If, however,
|
||
;;; sc-expand has already been registered as the expander to be used
|
||
;;; by eval, and eval accepts one argument, nothing special must be done
|
||
;;; to support the "noexpand" flag, since it is handled by sc-expand.
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||
;;;
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||
;;; (error who format-string why what)
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||
;;; where who is either a symbol or #f, format-string is always "~a ~s",
|
||
;;; why is always a string, and what may be any object. error should
|
||
;;; signal an error with a message something like
|
||
;;;
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||
;;; "error in <who>: <why> <what>"
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||
;;;
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||
;;; (gensym)
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||
;;; returns a unique symbol each time it's called
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||
;;;
|
||
;;; (putprop symbol key value)
|
||
;;; (getprop symbol key)
|
||
;;; key is always the symbol *sc-expander*; value may be any object.
|
||
;;; putprop should associate the given value with the given symbol in
|
||
;;; some way that it can be retrieved later with getprop.
|
||
|
||
;;; When porting to a new Scheme implementation, you should define the
|
||
;;; procedures listed above, load the expanded version of psyntax.ss
|
||
;;; (psyntax.pp, which should be available whereever you found
|
||
;;; psyntax.ss), and register sc-expand as the current expander (how
|
||
;;; you do this depends upon your implementation of Scheme). You may
|
||
;;; change the hooks and constructors defined toward the beginning of
|
||
;;; the code below, but to avoid bootstrapping problems, do so only
|
||
;;; after you have a working version of the expander.
|
||
|
||
;;; Chez Scheme allows the syntactic form (syntax <template>) to be
|
||
;;; abbreviated to #'<template>, just as (quote <datum>) may be
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||
;;; abbreviated to '<datum>. The #' syntax makes programs written
|
||
;;; using syntax-case shorter and more readable and draws out the
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||
;;; intuitive connection between syntax and quote.
|
||
|
||
;;; If you find that this code loads or runs slowly, consider
|
||
;;; switching to faster hardware or a faster implementation of
|
||
;;; Scheme. In Chez Scheme on a 200Mhz Pentium Pro, expanding,
|
||
;;; compiling (with full optimization), and loading this file takes
|
||
;;; between one and two seconds.
|
||
|
||
;;; In the expander implementation, we sometimes use syntactic abstractions
|
||
;;; when procedural abstractions would suffice. For example, we define
|
||
;;; top-wrap and top-marked? as
|
||
;;; (define-syntax top-wrap (identifier-syntax '((top))))
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||
;;; (define-syntax top-marked?
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||
;;; (syntax-rules ()
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||
;;; ((_ w) (memq 'top (wrap-marks w)))))
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||
;;; rather than
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;;; (define top-wrap '((top)))
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||
;;; (define top-marked?
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||
;;; (lambda (w) (memq 'top (wrap-marks w))))
|
||
;;; On ther other hand, we don't do this consistently; we define make-wrap,
|
||
;;; wrap-marks, and wrap-subst simply as
|
||
;;; (define make-wrap cons)
|
||
;;; (define wrap-marks car)
|
||
;;; (define wrap-subst cdr)
|
||
;;; In Chez Scheme, the syntactic and procedural forms of these
|
||
;;; abstractions are equivalent, since the optimizer consistently
|
||
;;; integrates constants and small procedures. Some Scheme
|
||
;;; implementations, however, may benefit from more consistent use
|
||
;;; of one form or the other.
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||
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||
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||
;;; implementation information:
|
||
|
||
;;; "begin" is treated as a splicing construct at top level and at
|
||
;;; the beginning of bodies. Any sequence of expressions that would
|
||
;;; be allowed where the "begin" occurs is allowed.
|
||
|
||
;;; "let-syntax" and "letrec-syntax" are also treated as splicing
|
||
;;; constructs, in violation of the R4RS appendix and probably the R5RS
|
||
;;; when it comes out. A consequence, let-syntax and letrec-syntax do
|
||
;;; not create local contours, as do let and letrec. Although the
|
||
;;; functionality is greater as it is presently implemented, we will
|
||
;;; probably change it to conform to the R4RS/expected R5RS.
|
||
|
||
;;; Objects with no standard print syntax, including objects containing
|
||
;;; cycles and syntax object, are allowed in quoted data as long as they
|
||
;;; are contained within a syntax form or produced by datum->syntax-object.
|
||
;;; Such objects are never copied.
|
||
|
||
;;; All identifiers that don't have macro definitions and are not bound
|
||
;;; lexically are assumed to be global variables
|
||
|
||
;;; Top-level definitions of macro-introduced identifiers are allowed.
|
||
;;; This may not be appropriate for implementations in which the
|
||
;;; model is that bindings are created by definitions, as opposed to
|
||
;;; one in which initial values are assigned by definitions.
|
||
|
||
;;; Top-level variable definitions of syntax keywords is not permitted.
|
||
;;; Any solution allowing this would be kludgey and would yield
|
||
;;; surprising results in some cases. We can provide an undefine-syntax
|
||
;;; form. The questions is, should define be an implicit undefine-syntax?
|
||
;;; We've decided no for now.
|
||
|
||
;;; Identifiers and syntax objects are implemented as vectors for
|
||
;;; portability. As a result, it is possible to "forge" syntax
|
||
;;; objects.
|
||
|
||
;;; The implementation of generate-temporaries assumes that it is possible
|
||
;;; to generate globally unique symbols (gensyms).
|
||
|
||
;;; The input to sc-expand may contain "annotations" describing, e.g., the
|
||
;;; source file and character position from where each object was read if
|
||
;;; it was read from a file. These annotations are handled properly by
|
||
;;; sc-expand only if the annotation? hook (see hooks below) is implemented
|
||
;;; properly and the operators make-annotation, annotation-expression,
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||
;;; annotation-source, annotation-stripped, and set-annotation-stripped!
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||
;;; are supplied. If annotations are supplied, the proper annotation
|
||
;;; source is passed to the various output constructors, allowing
|
||
;;; implementations to accurately correlate source and expanded code.
|
||
;;; Contact one of the authors for details if you wish to make use of
|
||
;;; this feature.
|
||
|
||
|
||
|
||
;;; Bootstrapping:
|
||
|
||
;;; When changing syntax-object representations, it is necessary to support
|
||
;;; both old and new syntax-object representations in id-var-name. It
|
||
;;; should be sufficient to recognize old representations and treat
|
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;;; them as not lexically bound.
|
||
|
||
|
||
|
||
(let ()
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||
(define-syntax define-structure
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||
(lambda (x)
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||
(define construct-name
|
||
(lambda (template-identifier . args)
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||
(datum->syntax-object
|
||
template-identifier
|
||
(string->symbol
|
||
(apply string-append
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||
(map (lambda (x)
|
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(if (string? x)
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x
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||
(symbol->string (syntax-object->datum x))))
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args))))))
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(syntax-case x ()
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((_ (name id1 ...))
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||
(andmap identifier? (syntax (name id1 ...)))
|
||
(with-syntax
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((constructor (construct-name (syntax name) "make-" (syntax name)))
|
||
(predicate (construct-name (syntax name) (syntax name) "?"))
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||
((access ...)
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||
(map (lambda (x) (construct-name x (syntax name) "-" x))
|
||
(syntax (id1 ...))))
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||
((assign ...)
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||
(map (lambda (x)
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||
(construct-name x "set-" (syntax name) "-" x "!"))
|
||
(syntax (id1 ...))))
|
||
(structure-length
|
||
(+ (length (syntax (id1 ...))) 1))
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||
((index ...)
|
||
(let f ((i 1) (ids (syntax (id1 ...))))
|
||
(if (null? ids)
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||
'()
|
||
(cons i (f (+ i 1) (cdr ids)))))))
|
||
(syntax (begin
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||
(define constructor
|
||
(lambda (id1 ...)
|
||
(vector 'name id1 ... )))
|
||
(define predicate
|
||
(lambda (x)
|
||
(and (vector? x)
|
||
(= (vector-length x) structure-length)
|
||
(eq? (vector-ref x 0) 'name))))
|
||
(define access
|
||
(lambda (x)
|
||
(vector-ref x index)))
|
||
...
|
||
(define assign
|
||
(lambda (x update)
|
||
(vector-set! x index update)))
|
||
...)))))))
|
||
|
||
(let ()
|
||
(define noexpand "noexpand")
|
||
|
||
;;; hooks to nonportable run-time helpers
|
||
(begin
|
||
(define fx+ +)
|
||
(define fx- -)
|
||
(define fx= =)
|
||
(define fx< <)
|
||
|
||
(define annotation? (lambda (x) #f))
|
||
|
||
(define top-level-eval-hook
|
||
(lambda (x)
|
||
(eval `(,noexpand ,x) (interaction-environment))))
|
||
|
||
(define local-eval-hook
|
||
(lambda (x)
|
||
(eval `(,noexpand ,x) (interaction-environment))))
|
||
|
||
(define error-hook
|
||
(lambda (who why what)
|
||
(error who "~a ~s" why what)))
|
||
|
||
(define-syntax gensym-hook
|
||
(syntax-rules ()
|
||
((_) (gensym))))
|
||
|
||
(define put-global-definition-hook
|
||
(lambda (symbol binding)
|
||
(putprop symbol '*sc-expander* binding)))
|
||
|
||
(define get-global-definition-hook
|
||
(lambda (symbol)
|
||
(getprop symbol '*sc-expander*)))
|
||
)
|
||
|
||
|
||
;;; output constructors
|
||
(begin
|
||
(define-syntax build-application
|
||
(syntax-rules ()
|
||
((_ source fun-exp arg-exps)
|
||
`(,fun-exp . ,arg-exps))))
|
||
|
||
(define-syntax build-conditional
|
||
(syntax-rules ()
|
||
((_ source test-exp then-exp else-exp)
|
||
`(if ,test-exp ,then-exp ,else-exp))))
|
||
|
||
(define-syntax build-lexical-reference
|
||
(syntax-rules ()
|
||
((_ type source var)
|
||
var)))
|
||
|
||
(define-syntax build-lexical-assignment
|
||
(syntax-rules ()
|
||
((_ source var exp)
|
||
`(set! ,var ,exp))))
|
||
|
||
(define-syntax build-global-reference
|
||
(syntax-rules ()
|
||
((_ source var)
|
||
var)))
|
||
|
||
(define-syntax build-global-assignment
|
||
(syntax-rules ()
|
||
((_ source var exp)
|
||
`(set! ,var ,exp))))
|
||
|
||
(define-syntax build-global-definition
|
||
(syntax-rules ()
|
||
((_ source var exp)
|
||
`(define ,var ,exp))))
|
||
|
||
(define-syntax build-lambda
|
||
(syntax-rules ()
|
||
((_ src vars exp)
|
||
`(lambda ,vars ,exp))))
|
||
|
||
(define-syntax build-primref
|
||
(syntax-rules ()
|
||
((_ src name) name)
|
||
((_ src level name) name)))
|
||
|
||
(define (build-data src exp)
|
||
(if (and (self-evaluating? exp)
|
||
(not (vector? exp)))
|
||
exp
|
||
(list 'quote exp)))
|
||
|
||
(define build-sequence
|
||
(lambda (src exps)
|
||
(if (null? (cdr exps))
|
||
(car exps)
|
||
`(begin ,@exps))))
|
||
|
||
(define build-let
|
||
(lambda (src vars val-exps body-exp)
|
||
(if (null? vars)
|
||
body-exp
|
||
`(let ,(map list vars val-exps) ,body-exp))))
|
||
|
||
(define build-named-let
|
||
(lambda (src vars val-exps body-exp)
|
||
(if (null? vars)
|
||
body-exp
|
||
`(let ,(car vars) ,(map list (cdr vars) val-exps) ,body-exp))))
|
||
|
||
(define build-letrec
|
||
(lambda (src vars val-exps body-exp)
|
||
(if (null? vars)
|
||
body-exp
|
||
`(letrec ,(map list vars val-exps) ,body-exp))))
|
||
|
||
(define-syntax build-lexical-var
|
||
(syntax-rules ()
|
||
((_ src id) (gensym (symbol->string id)))))
|
||
)
|
||
|
||
(define-structure (syntax-object expression wrap))
|
||
|
||
(define-syntax unannotate
|
||
(syntax-rules ()
|
||
((_ x)
|
||
(let ((e x))
|
||
(if (annotation? e)
|
||
(annotation-expression e)
|
||
e)))))
|
||
|
||
(define-syntax no-source (identifier-syntax #f))
|
||
|
||
(define source-annotation
|
||
(lambda (x)
|
||
(cond
|
||
((annotation? x) (annotation-source x))
|
||
((syntax-object? x) (source-annotation (syntax-object-expression x)))
|
||
(else no-source))))
|
||
|
||
(define-syntax arg-check
|
||
(syntax-rules ()
|
||
((_ pred? e who)
|
||
(let ((x e))
|
||
(if (not (pred? x)) (error-hook who "invalid argument" x))))))
|
||
|
||
;;; compile-time environments
|
||
|
||
;;; wrap and environment comprise two level mapping.
|
||
;;; wrap : id --> label
|
||
;;; env : label --> <element>
|
||
|
||
;;; environments are represented in two parts: a lexical part and a global
|
||
;;; part. The lexical part is a simple list of associations from labels
|
||
;;; to bindings. The global part is implemented by
|
||
;;; {put,get}-global-definition-hook and associates symbols with
|
||
;;; bindings.
|
||
|
||
;;; global (assumed global variable) and displaced-lexical (see below)
|
||
;;; do not show up in any environment; instead, they are fabricated by
|
||
;;; lookup when it finds no other bindings.
|
||
|
||
;;; <environment> ::= ((<label> . <binding>)*)
|
||
|
||
;;; identifier bindings include a type and a value
|
||
|
||
;;; <binding> ::= (macro . <procedure>) macros
|
||
;;; (core . <procedure>) core forms
|
||
;;; (external-macro . <procedure>) external-macro
|
||
;;; (begin) begin
|
||
;;; (define) define
|
||
;;; (define-syntax) define-syntax
|
||
;;; (local-syntax . rec?) let-syntax/letrec-syntax
|
||
;;; (eval-when) eval-when
|
||
;;; (syntax . (<var> . <level>)) pattern variables
|
||
;;; (global) assumed global variable
|
||
;;; (lexical . <var>) lexical variables
|
||
;;; (displaced-lexical) displaced lexicals
|
||
;;; <level> ::= <nonnegative integer>
|
||
;;; <var> ::= variable returned by build-lexical-var
|
||
|
||
;;; a macro is a user-defined syntactic-form. a core is a system-defined
|
||
;;; syntactic form. begin, define, define-syntax, and eval-when are
|
||
;;; treated specially since they are sensitive to whether the form is
|
||
;;; at top-level and (except for eval-when) can denote valid internal
|
||
;;; definitions.
|
||
|
||
;;; a pattern variable is a variable introduced by syntax-case and can
|
||
;;; be referenced only within a syntax form.
|
||
|
||
;;; any identifier for which no top-level syntax definition or local
|
||
;;; binding of any kind has been seen is assumed to be a global
|
||
;;; variable.
|
||
|
||
;;; a lexical variable is a lambda- or letrec-bound variable.
|
||
|
||
;;; a displaced-lexical identifier is a lexical identifier removed from
|
||
;;; it's scope by the return of a syntax object containing the identifier.
|
||
;;; a displaced lexical can also appear when a letrec-syntax-bound
|
||
;;; keyword is referenced on the rhs of one of the letrec-syntax clauses.
|
||
;;; a displaced lexical should never occur with properly written macros.
|
||
|
||
(define-syntax make-binding
|
||
(syntax-rules (quote)
|
||
((_ type value) (cons type value))
|
||
((_ 'type) '(type))
|
||
((_ type) (cons type '()))))
|
||
(define binding-type car)
|
||
(define binding-value cdr)
|
||
|
||
(define-syntax null-env (identifier-syntax '()))
|
||
|
||
(define extend-env
|
||
(lambda (labels bindings r)
|
||
(if (null? labels)
|
||
r
|
||
(extend-env (cdr labels) (cdr bindings)
|
||
(cons (cons (car labels) (car bindings)) r)))))
|
||
|
||
(define extend-var-env
|
||
; variant of extend-env that forms "lexical" binding
|
||
(lambda (labels vars r)
|
||
(if (null? labels)
|
||
r
|
||
(extend-var-env (cdr labels) (cdr vars)
|
||
(cons (cons (car labels) (make-binding 'lexical (car vars))) r)))))
|
||
|
||
;;; we use a "macros only" environment in expansion of local macro
|
||
;;; definitions so that their definitions can use local macros without
|
||
;;; attempting to use other lexical identifiers.
|
||
(define macros-only-env
|
||
(lambda (r)
|
||
(if (null? r)
|
||
'()
|
||
(let ((a (car r)))
|
||
(if (memq (cadr a) '(macro ellipsis))
|
||
(cons a (macros-only-env (cdr r)))
|
||
(macros-only-env (cdr r)))))))
|
||
|
||
(define lookup
|
||
; x may be a label or a symbol
|
||
; although symbols are usually global, we check the environment first
|
||
; anyway because a temporary binding may have been established by
|
||
; fluid-let-syntax
|
||
(lambda (x r)
|
||
(cond
|
||
((assq x r) => cdr)
|
||
((symbol? x)
|
||
(or (get-global-definition-hook x) (make-binding 'global)))
|
||
(else (make-binding 'displaced-lexical)))))
|
||
|
||
(define global-extend
|
||
(lambda (type sym val)
|
||
(put-global-definition-hook sym (make-binding type val))))
|
||
|
||
|
||
;;; Conceptually, identifiers are always syntax objects. Internally,
|
||
;;; however, the wrap is sometimes maintained separately (a source of
|
||
;;; efficiency and confusion), so that symbols are also considered
|
||
;;; identifiers by id?. Externally, they are always wrapped.
|
||
|
||
(define nonsymbol-id?
|
||
(lambda (x)
|
||
(and (syntax-object? x)
|
||
(symbol? (unannotate (syntax-object-expression x))))))
|
||
|
||
(define id?
|
||
(lambda (x)
|
||
(cond
|
||
((symbol? x) #t)
|
||
((syntax-object? x) (symbol? (unannotate (syntax-object-expression x))))
|
||
((annotation? x) (symbol? (annotation-expression x)))
|
||
(else #f))))
|
||
|
||
(define-syntax id-sym-name
|
||
(syntax-rules ()
|
||
((_ e)
|
||
(let ((x e))
|
||
(unannotate (if (syntax-object? x) (syntax-object-expression x) x))))))
|
||
|
||
(define id-sym-name&marks
|
||
(lambda (x w)
|
||
(if (syntax-object? x)
|
||
(values
|
||
(unannotate (syntax-object-expression x))
|
||
(join-marks (wrap-marks w) (wrap-marks (syntax-object-wrap x))))
|
||
(values (unannotate x) (wrap-marks w)))))
|
||
|
||
;;; syntax object wraps
|
||
|
||
;;; <wrap> ::= ((<mark> ...) . (<subst> ...))
|
||
;;; <subst> ::= <shift> | <subs>
|
||
;;; <subs> ::= #(<old name> <label> (<mark> ...))
|
||
;;; <shift> ::= positive fixnum
|
||
|
||
(define make-wrap cons)
|
||
(define wrap-marks car)
|
||
(define wrap-subst cdr)
|
||
|
||
(define-syntax subst-rename? (identifier-syntax vector?))
|
||
(define-syntax rename-old (syntax-rules () ((_ x) (vector-ref x 0))))
|
||
(define-syntax rename-new (syntax-rules () ((_ x) (vector-ref x 1))))
|
||
(define-syntax rename-marks (syntax-rules () ((_ x) (vector-ref x 2))))
|
||
(define-syntax make-rename
|
||
(syntax-rules ()
|
||
((_ old new marks) (vector old new marks))))
|
||
|
||
;;; labels must be comparable with "eq?" and distinct from symbols.
|
||
(define gen-label
|
||
(lambda () (string #\i)))
|
||
|
||
(define gen-labels
|
||
(lambda (ls)
|
||
(if (null? ls)
|
||
'()
|
||
(cons (gen-label) (gen-labels (cdr ls))))))
|
||
|
||
(define-structure (ribcage symnames marks labels))
|
||
|
||
(define-syntax empty-wrap (identifier-syntax '(())))
|
||
|
||
(define-syntax top-wrap (identifier-syntax '((top))))
|
||
|
||
(define-syntax top-marked?
|
||
(syntax-rules ()
|
||
((_ w) (memq 'top (wrap-marks w)))))
|
||
|
||
;;; Marks must be comparable with "eq?" and distinct from pairs and
|
||
;;; the symbol top. We do not use integers so that marks will remain
|
||
;;; unique even across file compiles.
|
||
|
||
(define-syntax the-anti-mark (identifier-syntax #f))
|
||
|
||
(define anti-mark
|
||
(lambda (w)
|
||
(make-wrap (cons the-anti-mark (wrap-marks w))
|
||
(cons 'shift (wrap-subst w)))))
|
||
|
||
(define-syntax new-mark
|
||
(syntax-rules ()
|
||
((_) (string #\m))))
|
||
|
||
;;; make-empty-ribcage and extend-ribcage maintain list-based ribcages for
|
||
;;; internal definitions, in which the ribcages are built incrementally
|
||
(define-syntax make-empty-ribcage
|
||
(syntax-rules ()
|
||
((_) (make-ribcage '() '() '()))))
|
||
|
||
(define extend-ribcage!
|
||
; must receive ids with complete wraps
|
||
(lambda (ribcage id label)
|
||
(set-ribcage-symnames! ribcage
|
||
(cons (unannotate (syntax-object-expression id))
|
||
(ribcage-symnames ribcage)))
|
||
(set-ribcage-marks! ribcage
|
||
(cons (wrap-marks (syntax-object-wrap id))
|
||
(ribcage-marks ribcage)))
|
||
(set-ribcage-labels! ribcage
|
||
(cons label (ribcage-labels ribcage)))))
|
||
|
||
;;; make-binding-wrap creates vector-based ribcages
|
||
(define make-binding-wrap
|
||
(lambda (ids labels w)
|
||
(if (null? ids)
|
||
w
|
||
(make-wrap
|
||
(wrap-marks w)
|
||
(cons
|
||
(let ((labelvec (list->vector labels)))
|
||
(let ((n (vector-length labelvec)))
|
||
(let ((symnamevec (make-vector n)) (marksvec (make-vector n)))
|
||
(let f ((ids ids) (i 0))
|
||
(if (not (null? ids))
|
||
(call-with-values
|
||
(lambda () (id-sym-name&marks (car ids) w))
|
||
(lambda (symname marks)
|
||
(vector-set! symnamevec i symname)
|
||
(vector-set! marksvec i marks)
|
||
(f (cdr ids) (fx+ i 1))))))
|
||
(make-ribcage symnamevec marksvec labelvec))))
|
||
(wrap-subst w))))))
|
||
|
||
(define smart-append
|
||
(lambda (m1 m2)
|
||
(if (null? m2)
|
||
m1
|
||
(append m1 m2))))
|
||
|
||
(define join-wraps
|
||
(lambda (w1 w2)
|
||
(let ((m1 (wrap-marks w1)) (s1 (wrap-subst w1)))
|
||
(if (null? m1)
|
||
(if (null? s1)
|
||
w2
|
||
(make-wrap
|
||
(wrap-marks w2)
|
||
(smart-append s1 (wrap-subst w2))))
|
||
(make-wrap
|
||
(smart-append m1 (wrap-marks w2))
|
||
(smart-append s1 (wrap-subst w2)))))))
|
||
|
||
(define join-marks
|
||
(lambda (m1 m2)
|
||
(smart-append m1 m2)))
|
||
|
||
(define same-marks?
|
||
(lambda (x y)
|
||
(or (eq? x y)
|
||
(and (not (null? x))
|
||
(not (null? y))
|
||
(eq? (car x) (car y))
|
||
(same-marks? (cdr x) (cdr y))))))
|
||
|
||
(define id-var-name
|
||
(lambda (id w)
|
||
(define-syntax first
|
||
(syntax-rules ()
|
||
((_ e) (call-with-values (lambda () e) (lambda (x . ignore) x)))))
|
||
(define search
|
||
(lambda (sym subst marks)
|
||
(if (null? subst)
|
||
(values #f marks)
|
||
(let ((fst (car subst)))
|
||
(if (eq? fst 'shift)
|
||
(search sym (cdr subst) (cdr marks))
|
||
(let ((symnames (ribcage-symnames fst)))
|
||
(if (vector? symnames)
|
||
(search-vector-rib sym subst marks symnames fst)
|
||
(search-list-rib sym subst marks symnames fst))))))))
|
||
(define search-list-rib
|
||
(lambda (sym subst marks symnames ribcage)
|
||
(let f ((symnames symnames) (i 0))
|
||
(cond
|
||
((null? symnames) (search sym (cdr subst) marks))
|
||
((and (eq? (car symnames) sym)
|
||
(same-marks? marks (list-ref (ribcage-marks ribcage) i)))
|
||
(values (list-ref (ribcage-labels ribcage) i) marks))
|
||
(else (f (cdr symnames) (fx+ i 1)))))))
|
||
(define search-vector-rib
|
||
(lambda (sym subst marks symnames ribcage)
|
||
(let ((n (vector-length symnames)))
|
||
(let f ((i 0))
|
||
(cond
|
||
((fx= i n) (search sym (cdr subst) marks))
|
||
((and (eq? (vector-ref symnames i) sym)
|
||
(same-marks? marks (vector-ref (ribcage-marks ribcage) i)))
|
||
(values (vector-ref (ribcage-labels ribcage) i) marks))
|
||
(else (f (fx+ i 1))))))))
|
||
(cond
|
||
((symbol? id)
|
||
(or (first (search id (wrap-subst w) (wrap-marks w))) id))
|
||
((syntax-object? id)
|
||
(let ((id (unannotate (syntax-object-expression id)))
|
||
(w1 (syntax-object-wrap id)))
|
||
(let ((marks (join-marks (wrap-marks w) (wrap-marks w1))))
|
||
(call-with-values (lambda () (search id (wrap-subst w) marks))
|
||
(lambda (new-id marks)
|
||
(or new-id
|
||
(first (search id (wrap-subst w1) marks))
|
||
id))))))
|
||
((annotation? id)
|
||
(let ((id (unannotate id)))
|
||
(or (first (search id (wrap-subst w) (wrap-marks w))) id)))
|
||
(else (error-hook 'id-var-name "invalid id" id)))))
|
||
|
||
;;; free-id=? must be passed fully wrapped ids since (free-id=? x y)
|
||
;;; may be true even if (free-id=? (wrap x w) (wrap y w)) is not.
|
||
|
||
(define free-id=?
|
||
(lambda (i j)
|
||
(and (eq? (id-sym-name i) (id-sym-name j)) ; accelerator
|
||
(eq? (id-var-name i empty-wrap) (id-var-name j empty-wrap)))))
|
||
|
||
;;; bound-id=? may be passed unwrapped (or partially wrapped) ids as
|
||
;;; long as the missing portion of the wrap is common to both of the ids
|
||
;;; since (bound-id=? x y) iff (bound-id=? (wrap x w) (wrap y w))
|
||
|
||
(define bound-id=?
|
||
(lambda (i j)
|
||
(if (and (syntax-object? i) (syntax-object? j))
|
||
(and (eq? (unannotate (syntax-object-expression i))
|
||
(unannotate (syntax-object-expression j)))
|
||
(same-marks? (wrap-marks (syntax-object-wrap i))
|
||
(wrap-marks (syntax-object-wrap j))))
|
||
(eq? (unannotate i) (unannotate j)))))
|
||
|
||
;;; "valid-bound-ids?" returns #t if it receives a list of distinct ids.
|
||
;;; valid-bound-ids? may be passed unwrapped (or partially wrapped) ids
|
||
;;; as long as the missing portion of the wrap is common to all of the
|
||
;;; ids.
|
||
|
||
(define valid-bound-ids?
|
||
(lambda (ids)
|
||
(and (let all-ids? ((ids ids))
|
||
(or (null? ids)
|
||
(and (id? (car ids))
|
||
(all-ids? (cdr ids)))))
|
||
(distinct-bound-ids? ids))))
|
||
|
||
;;; distinct-bound-ids? expects a list of ids and returns #t if there are
|
||
;;; no duplicates. It is quadratic on the length of the id list; long
|
||
;;; lists could be sorted to make it more efficient. distinct-bound-ids?
|
||
;;; may be passed unwrapped (or partially wrapped) ids as long as the
|
||
;;; missing portion of the wrap is common to all of the ids.
|
||
|
||
(define distinct-bound-ids?
|
||
(lambda (ids)
|
||
(let distinct? ((ids ids))
|
||
(or (null? ids)
|
||
(and (not (bound-id-member? (car ids) (cdr ids)))
|
||
(distinct? (cdr ids)))))))
|
||
|
||
(define bound-id-member?
|
||
(lambda (x list)
|
||
(and (not (null? list))
|
||
(or (bound-id=? x (car list))
|
||
(bound-id-member? x (cdr list))))))
|
||
|
||
;;; wrapping expressions and identifiers
|
||
|
||
(define wrap
|
||
(lambda (x w)
|
||
(cond
|
||
((and (null? (wrap-marks w)) (null? (wrap-subst w))) x)
|
||
((syntax-object? x)
|
||
(make-syntax-object
|
||
(syntax-object-expression x)
|
||
(join-wraps w (syntax-object-wrap x))))
|
||
((null? x) x)
|
||
(else (make-syntax-object x w)))))
|
||
|
||
(define source-wrap
|
||
(lambda (x w s)
|
||
(wrap (if s (make-annotation x s #f) x) w)))
|
||
|
||
;;; expanding
|
||
|
||
(define chi-sequence
|
||
(lambda (body r w s)
|
||
(build-sequence s
|
||
(let dobody ((body body) (r r) (w w))
|
||
(if (null? body)
|
||
'()
|
||
(let ((first (chi (car body) r w)))
|
||
(cons first (dobody (cdr body) r w))))))))
|
||
|
||
(define chi-top-sequence
|
||
(lambda (body r w s m esew)
|
||
(build-sequence s
|
||
(let dobody ((body body) (r r) (w w) (m m) (esew esew))
|
||
(if (null? body)
|
||
'()
|
||
(let ((first (chi-top (car body) r w m esew)))
|
||
(cons first (dobody (cdr body) r w m esew))))))))
|
||
|
||
(define chi-install-global
|
||
(lambda (name e)
|
||
(build-application no-source
|
||
(build-primref no-source 'install-global-transformer)
|
||
(list (build-data no-source name) e))))
|
||
|
||
(define chi-when-list
|
||
(lambda (e when-list w)
|
||
; when-list is syntax'd version of list of situations
|
||
(let f ((when-list when-list) (situations '()))
|
||
(if (null? when-list)
|
||
situations
|
||
(f (cdr when-list)
|
||
(cons (let ((x (car when-list)))
|
||
(cond
|
||
((free-id=? x (syntax compile)) 'compile)
|
||
((free-id=? x (syntax load)) 'load)
|
||
((free-id=? x (syntax eval)) 'eval)
|
||
(else (syntax-error (wrap x w)
|
||
"invalid eval-when situation"))))
|
||
situations))))))
|
||
|
||
;;; syntax-type returns five values: type, value, e, w, and s. The first
|
||
;;; two are described in the table below.
|
||
;;;
|
||
;;; type value explanation
|
||
;;; -------------------------------------------------------------------
|
||
;;; core procedure core form (including singleton)
|
||
;;; external-macro procedure external macro
|
||
;;; lexical name lexical variable reference
|
||
;;; global name global variable reference
|
||
;;; begin none begin keyword
|
||
;;; define none define keyword
|
||
;;; define-syntax none define-syntax keyword
|
||
;;; local-syntax rec? letrec-syntax/let-syntax keyword
|
||
;;; eval-when none eval-when keyword
|
||
;;; syntax level pattern variable
|
||
;;; displaced-lexical none displaced lexical identifier
|
||
;;; lexical-call name call to lexical variable
|
||
;;; global-call name call to global variable
|
||
;;; call none any other call
|
||
;;; begin-form none begin expression
|
||
;;; define-form id variable definition
|
||
;;; define-syntax-form id syntax definition
|
||
;;; local-syntax-form rec? syntax definition
|
||
;;; eval-when-form none eval-when form
|
||
;;; constant none self-evaluating datum
|
||
;;; other none anything else
|
||
;;;
|
||
;;; For define-form and define-syntax-form, e is the rhs expression.
|
||
;;; For all others, e is the entire form. w is the wrap for e.
|
||
;;; s is the source for the entire form.
|
||
;;;
|
||
;;; syntax-type expands macros and unwraps as necessary to get to
|
||
;;; one of the forms above. It also parses define and define-syntax
|
||
;;; forms, although perhaps this should be done by the consumer.
|
||
|
||
(define syntax-type
|
||
(lambda (e r w s rib)
|
||
(cond
|
||
((symbol? e)
|
||
(let* ((n (id-var-name e w))
|
||
(b (lookup n r))
|
||
(type (binding-type b)))
|
||
(case type
|
||
((lexical) (values type (binding-value b) e w s))
|
||
((global) (values type n e w s))
|
||
((macro)
|
||
(syntax-type (chi-macro (binding-value b) e r w rib) r empty-wrap s rib))
|
||
(else (values type (binding-value b) e w s)))))
|
||
((pair? e)
|
||
(let ((first (car e)))
|
||
(if (id? first)
|
||
(let* ((n (id-var-name first w))
|
||
(b (lookup n r))
|
||
(type (binding-type b)))
|
||
(case type
|
||
((lexical) (values 'lexical-call (binding-value b) e w s))
|
||
((global) (values 'global-call n e w s))
|
||
((macro)
|
||
(syntax-type (chi-macro (binding-value b) e r w rib)
|
||
r empty-wrap s rib))
|
||
((core external-macro) (values type (binding-value b) e w s))
|
||
((local-syntax)
|
||
(values 'local-syntax-form (binding-value b) e w s))
|
||
((begin) (values 'begin-form #f e w s))
|
||
((eval-when) (values 'eval-when-form #f e w s))
|
||
((define)
|
||
(syntax-case e ()
|
||
((_ name val)
|
||
(id? (syntax name))
|
||
(values 'define-form (syntax name) (syntax val) w s))
|
||
((_ (name . args) e1 e2 ...)
|
||
(and (id? (syntax name))
|
||
(valid-bound-ids? (lambda-var-list (syntax args))))
|
||
; need lambda here...
|
||
(values 'define-form (wrap (syntax name) w)
|
||
(cons (syntax lambda) (wrap (syntax (args e1 e2 ...)) w))
|
||
empty-wrap s))
|
||
((_ name)
|
||
(id? (syntax name))
|
||
(values 'define-form (wrap (syntax name) w)
|
||
(syntax (void))
|
||
empty-wrap s))))
|
||
((define-syntax)
|
||
(syntax-case e ()
|
||
((_ name val)
|
||
(id? (syntax name))
|
||
(values 'define-syntax-form (syntax name)
|
||
(syntax val) w s))))
|
||
((ellipsis)
|
||
(values 'ellipsis
|
||
(make-syntax-object (syntax-object-expression value)
|
||
(anti-mark (syntax-object-wrap value)))))
|
||
(else (values 'call #f e w s))))
|
||
(values 'call #f e w s))))
|
||
((syntax-object? e)
|
||
;; s can't be valid source if we've unwrapped
|
||
(syntax-type (syntax-object-expression e)
|
||
r
|
||
(join-wraps w (syntax-object-wrap e))
|
||
no-source rib))
|
||
((annotation? e)
|
||
(syntax-type (annotation-expression e) r w (annotation-source e) rib))
|
||
((self-evaluating? e) (values 'constant #f e w s))
|
||
(else (values 'other #f e w s)))))
|
||
|
||
(define chi-top
|
||
(lambda (e r w m esew)
|
||
(define-syntax eval-if-c&e
|
||
(syntax-rules ()
|
||
((_ m e)
|
||
(let ((x e))
|
||
(if (eq? m 'c&e) (top-level-eval-hook x))
|
||
x))))
|
||
(call-with-values
|
||
(lambda () (syntax-type e r w no-source #f))
|
||
(lambda (type value e w s)
|
||
(case type
|
||
((begin-form)
|
||
(syntax-case e ()
|
||
((_) (chi-void))
|
||
((_ e1 e2 ...)
|
||
(chi-top-sequence (syntax (e1 e2 ...)) r w s m esew))))
|
||
((local-syntax-form)
|
||
(chi-local-syntax value e r w s
|
||
(lambda (body r w s)
|
||
(chi-top-sequence body r w s m esew))))
|
||
((eval-when-form)
|
||
(syntax-case e ()
|
||
((_ (x ...) e1 e2 ...)
|
||
(let ((when-list (chi-when-list e (syntax (x ...)) w))
|
||
(body (syntax (e1 e2 ...))))
|
||
(cond
|
||
((eq? m 'e)
|
||
(if (memq 'eval when-list)
|
||
(chi-top-sequence body r w s 'e '(eval))
|
||
(chi-void)))
|
||
((memq 'load when-list)
|
||
(if (or (memq 'compile when-list)
|
||
(and (eq? m 'c&e) (memq 'eval when-list)))
|
||
(chi-top-sequence body r w s 'c&e '(compile load))
|
||
(if (memq m '(c c&e))
|
||
(chi-top-sequence body r w s 'c '(load))
|
||
(chi-void))))
|
||
((or (memq 'compile when-list)
|
||
(and (eq? m 'c&e) (memq 'eval when-list)))
|
||
(top-level-eval-hook
|
||
(chi-top-sequence body r w s 'e '(eval)))
|
||
(chi-void))
|
||
(else (chi-void)))))))
|
||
((define-syntax-form)
|
||
(let ((n (id-var-name value w)) (r (macros-only-env r)))
|
||
(case m
|
||
((c)
|
||
(if (memq 'compile esew)
|
||
(let ((e (chi-install-global n (chi e r w))))
|
||
(top-level-eval-hook e)
|
||
(if (memq 'load esew) e (chi-void)))
|
||
(if (memq 'load esew)
|
||
(chi-install-global n (chi e r w))
|
||
(chi-void))))
|
||
((c&e)
|
||
(let ((e (chi-install-global n (chi e r w))))
|
||
(top-level-eval-hook e)
|
||
e))
|
||
(else
|
||
(if (memq 'eval esew)
|
||
(top-level-eval-hook
|
||
(chi-install-global n (chi e r w))))
|
||
(chi-void)))))
|
||
((define-form)
|
||
(let* ((n (id-var-name value w))
|
||
(type (binding-type (lookup n r))))
|
||
(case type
|
||
((global)
|
||
(eval-if-c&e m
|
||
(build-global-definition s n (chi e r w))))
|
||
((displaced-lexical)
|
||
(syntax-error (wrap value w) "identifier out of context"))
|
||
(else
|
||
(if (eq? type 'external-macro)
|
||
(eval-if-c&e m
|
||
(build-global-definition s n (chi e r w)))
|
||
(syntax-error (wrap value w)
|
||
"cannot define keyword at top level"))))))
|
||
(else (eval-if-c&e m (chi-expr type value e r w s))))))))
|
||
|
||
(define chi
|
||
(lambda (e r w)
|
||
(call-with-values
|
||
(lambda () (syntax-type e r w no-source #f))
|
||
(lambda (type value e w s)
|
||
(chi-expr type value e r w s)))))
|
||
|
||
(define chi-expr
|
||
(lambda (type value e r w s)
|
||
(case type
|
||
((lexical)
|
||
(build-lexical-reference 'value s value))
|
||
((core external-macro) (value e r w s))
|
||
((lexical-call)
|
||
(chi-application
|
||
(build-lexical-reference 'fun (source-annotation (car e)) value)
|
||
e r w s))
|
||
((global-call)
|
||
(chi-application
|
||
(build-global-reference (source-annotation (car e)) value)
|
||
e r w s))
|
||
((constant) (build-data s (strip (source-wrap e w s) empty-wrap)))
|
||
((global) (build-global-reference s value))
|
||
((call) (chi-application (chi (car e) r w) e r w s))
|
||
((begin-form)
|
||
(syntax-case e ()
|
||
((_ e1 e2 ...) (chi-sequence (syntax (e1 e2 ...)) r w s))))
|
||
((local-syntax-form)
|
||
(chi-local-syntax value e r w s chi-sequence))
|
||
((eval-when-form)
|
||
(syntax-case e ()
|
||
((_ (x ...) e1 e2 ...)
|
||
(let ((when-list (chi-when-list e (syntax (x ...)) w)))
|
||
(if (memq 'eval when-list)
|
||
(chi-sequence (syntax (e1 e2 ...)) r w s)
|
||
(chi-void))))))
|
||
((define-form define-syntax-form)
|
||
(syntax-error (wrap value w) "invalid context for definition of"))
|
||
((syntax)
|
||
(syntax-error (source-wrap e w s)
|
||
"reference to pattern variable outside syntax form"))
|
||
((displaced-lexical)
|
||
(syntax-error (source-wrap e w s)
|
||
"reference to identifier outside its scope"))
|
||
(else (syntax-error (source-wrap e w s))))))
|
||
|
||
(define chi-application
|
||
(lambda (x e r w s)
|
||
(syntax-case e ()
|
||
((e0 e1 ...)
|
||
(build-application s x
|
||
(map (lambda (e) (chi e r w)) (syntax (e1 ...))))))))
|
||
|
||
(define chi-macro
|
||
(lambda (p e r w rib)
|
||
(define rebuild-macro-output
|
||
(lambda (x m)
|
||
(cond ((pair? x)
|
||
(cons (rebuild-macro-output (car x) m)
|
||
(rebuild-macro-output (cdr x) m)))
|
||
((syntax-object? x)
|
||
(let ((w (syntax-object-wrap x)))
|
||
(let ((ms (wrap-marks w)) (s (wrap-subst w)))
|
||
(make-syntax-object (syntax-object-expression x)
|
||
(if (and (pair? ms) (eq? (car ms) the-anti-mark))
|
||
(make-wrap (cdr ms)
|
||
(if rib (cons rib (cdr s)) (cdr s)))
|
||
(make-wrap (cons m ms)
|
||
(if rib
|
||
(cons rib (cons 'shift s))
|
||
(cons 'shift s))))))))
|
||
((vector? x)
|
||
(let* ((n (vector-length x)) (v (make-vector n)))
|
||
(do ((i 0 (fx+ i 1)))
|
||
((fx= i n) v)
|
||
(vector-set! v i
|
||
(rebuild-macro-output (vector-ref x i) m)))))
|
||
((symbol? x)
|
||
(syntax-error x "encountered raw symbol in macro output"))
|
||
(else x))))
|
||
(rebuild-macro-output (p (wrap e (anti-mark w))) (new-mark))))
|
||
|
||
(define chi-body
|
||
;; In processing the forms of the body, we create a new, empty wrap.
|
||
;; This wrap is augmented (destructively) each time we discover that
|
||
;; the next form is a definition. This is done:
|
||
;;
|
||
;; (1) to allow the first nondefinition form to be a call to
|
||
;; one of the defined ids even if the id previously denoted a
|
||
;; definition keyword or keyword for a macro expanding into a
|
||
;; definition;
|
||
;; (2) to prevent subsequent definition forms (but unfortunately
|
||
;; not earlier ones) and the first nondefinition form from
|
||
;; confusing one of the bound identifiers for an auxiliary
|
||
;; keyword; and
|
||
;; (3) so that we do not need to restart the expansion of the
|
||
;; first nondefinition form, which is problematic anyway
|
||
;; since it might be the first element of a begin that we
|
||
;; have just spliced into the body (meaning if we restarted,
|
||
;; we'd really need to restart with the begin or the macro
|
||
;; call that expanded into the begin, and we'd have to give
|
||
;; up allowing (begin <defn>+ <expr>+), which is itself
|
||
;; problematic since we don't know if a begin contains only
|
||
;; definitions until we've expanded it).
|
||
;;
|
||
;; Before processing the body, we also create a new environment
|
||
;; containing a placeholder for the bindings we will add later and
|
||
;; associate this environment with each form. In processing a
|
||
;; let-syntax or letrec-syntax, the associated environment may be
|
||
;; augmented with local keyword bindings, so the environment may
|
||
;; be different for different forms in the body. Once we have
|
||
;; gathered up all of the definitions, we evaluate the transformer
|
||
;; expressions and splice into r at the placeholder the new variable
|
||
;; and keyword bindings. This allows let-syntax or letrec-syntax
|
||
;; forms local to a portion or all of the body to shadow the
|
||
;; definition bindings.
|
||
;;
|
||
;; Subforms of a begin, let-syntax, or letrec-syntax are spliced
|
||
;; into the body.
|
||
;;
|
||
;; outer-form is fully wrapped w/source
|
||
(lambda (body outer-form r w)
|
||
(let* ((r (cons '("placeholder" . (placeholder)) r))
|
||
(ribcage (make-empty-ribcage))
|
||
(w (make-wrap (wrap-marks w) (cons ribcage (wrap-subst w)))))
|
||
(let parse ((body (map (lambda (x) (cons r (wrap x w))) body))
|
||
(ids '()) (labels '()) (vars '()) (vals '()) (bindings '()))
|
||
(if (null? body)
|
||
(syntax-error outer-form "no expressions in body")
|
||
(let ((e (cdar body)) (er (caar body)))
|
||
(call-with-values
|
||
(lambda () (syntax-type e er empty-wrap no-source ribcage))
|
||
(lambda (type value e w s)
|
||
(case type
|
||
((define-form)
|
||
(let ((id (wrap value w)) (label (gen-label)))
|
||
(let ((var (gen-var id)))
|
||
(extend-ribcage! ribcage id label)
|
||
(parse (cdr body)
|
||
(cons id ids) (cons label labels)
|
||
(cons var vars) (cons (cons er (wrap e w)) vals)
|
||
(cons (make-binding 'lexical var) bindings)))))
|
||
((define-syntax-form)
|
||
(let ((id (wrap value w)) (label (gen-label)))
|
||
(extend-ribcage! ribcage id label)
|
||
(parse (cdr body)
|
||
(cons id ids) (cons label labels)
|
||
vars vals
|
||
(cons (make-binding 'macro (cons er (wrap e w)))
|
||
bindings))))
|
||
((begin-form)
|
||
(syntax-case e ()
|
||
((_ e1 ...)
|
||
(parse (let f ((forms (syntax (e1 ...))))
|
||
(if (null? forms)
|
||
(cdr body)
|
||
(cons (cons er (wrap (car forms) w))
|
||
(f (cdr forms)))))
|
||
ids labels vars vals bindings))))
|
||
((local-syntax-form)
|
||
(chi-local-syntax value e er w s
|
||
(lambda (forms er w s)
|
||
(parse (let f ((forms forms))
|
||
(if (null? forms)
|
||
(cdr body)
|
||
(cons (cons er (wrap (car forms) w))
|
||
(f (cdr forms)))))
|
||
ids labels vars vals bindings))))
|
||
(else ; found a non-definition
|
||
(if (null? ids)
|
||
(build-sequence no-source
|
||
(map (lambda (x)
|
||
(chi (cdr x) (car x) empty-wrap))
|
||
(cons (cons er (source-wrap e w s))
|
||
(cdr body))))
|
||
(begin
|
||
(if (not (valid-bound-ids? ids))
|
||
(syntax-error outer-form
|
||
"invalid or duplicate identifier in definition"))
|
||
(let loop ((bs bindings) (er-cache #f) (r-cache #f))
|
||
(if (not (null? bs))
|
||
(let* ((b (car bs)))
|
||
(if (eq? (car b) 'macro)
|
||
(let* ((er (cadr b))
|
||
(r-cache
|
||
(if (eq? er er-cache)
|
||
r-cache
|
||
(macros-only-env er))))
|
||
(set-cdr! b
|
||
(eval-local-transformer
|
||
(chi (cddr b) r-cache empty-wrap)))
|
||
(loop (cdr bs) er r-cache))
|
||
(loop (cdr bs) er-cache r-cache)))))
|
||
(set-cdr! r (extend-env labels bindings (cdr r)))
|
||
(build-letrec no-source
|
||
vars
|
||
(map (lambda (x)
|
||
(chi (cdr x) (car x) empty-wrap))
|
||
vals)
|
||
(build-sequence no-source
|
||
(map (lambda (x)
|
||
(chi (cdr x) (car x) empty-wrap))
|
||
(cons (cons er (source-wrap e w s))
|
||
(cdr body)))))))))))))))))
|
||
|
||
(define chi-lambda-clause
|
||
(lambda (e c r w k)
|
||
(syntax-case c ()
|
||
(((id ...) e1 e2 ...)
|
||
(let ((ids (syntax (id ...))))
|
||
(if (not (valid-bound-ids? ids))
|
||
(syntax-error e "invalid parameter list in")
|
||
(let ((labels (gen-labels ids))
|
||
(new-vars (map gen-var ids)))
|
||
(k new-vars
|
||
(chi-body (syntax (e1 e2 ...))
|
||
e
|
||
(extend-var-env labels new-vars r)
|
||
(make-binding-wrap ids labels w)))))))
|
||
((ids e1 e2 ...)
|
||
(let ((old-ids (lambda-var-list (syntax ids))))
|
||
(if (not (valid-bound-ids? old-ids))
|
||
(syntax-error e "invalid parameter list in")
|
||
(let ((labels (gen-labels old-ids))
|
||
(new-vars (map gen-var old-ids)))
|
||
(k (let f ((ls1 (cdr new-vars)) (ls2 (car new-vars)))
|
||
(if (null? ls1)
|
||
ls2
|
||
(f (cdr ls1) (cons (car ls1) ls2))))
|
||
(chi-body (syntax (e1 e2 ...))
|
||
e
|
||
(extend-var-env labels new-vars r)
|
||
(make-binding-wrap old-ids labels w)))))))
|
||
(_ (syntax-error e)))))
|
||
|
||
(define chi-local-syntax
|
||
(lambda (rec? e r w s k)
|
||
(syntax-case e ()
|
||
((_ ((id val) ...) e1 e2 ...)
|
||
(let ((ids (syntax (id ...))))
|
||
(if (not (valid-bound-ids? ids))
|
||
(syntax-error e "duplicate bound keyword in")
|
||
(let ((labels (gen-labels ids)))
|
||
(let ((new-w (make-binding-wrap ids labels w)))
|
||
(k (syntax (e1 e2 ...))
|
||
(extend-env
|
||
labels
|
||
(let ((w (if rec? new-w w))
|
||
(trans-r (macros-only-env r)))
|
||
(map (lambda (x)
|
||
(make-binding 'macro
|
||
(eval-local-transformer (chi x trans-r w))))
|
||
(syntax (val ...))))
|
||
r)
|
||
new-w
|
||
s))))))
|
||
(_ (syntax-error (source-wrap e w s))))))
|
||
|
||
(define eval-local-transformer
|
||
(lambda (expanded)
|
||
(let ((p (local-eval-hook expanded)))
|
||
(if (procedure? p)
|
||
p
|
||
(syntax-error p "nonprocedure transformer")))))
|
||
|
||
(define chi-void
|
||
(lambda ()
|
||
(build-application no-source (build-primref no-source 'void) '())))
|
||
|
||
(define ellipsis?
|
||
(lambda (e r)
|
||
(and (nonsymbol-id? e)
|
||
;; If there is a binding for the special identifier
|
||
;; #{ $sc-ellipsis }# in the lexical environment of E,
|
||
;; and if the associated binding type is 'ellipsis',
|
||
;; then the binding's value specifies the custom ellipsis
|
||
;; identifier within that lexical environment, and the
|
||
;; comparison is done using 'bound-id=?'.
|
||
(let* ((id (make-syntax-object '$sc-ellipsis
|
||
(syntax-object-wrap e)))
|
||
(n (id-var-name id empty-wrap))
|
||
(b (lookup n r)))
|
||
(if (eq? (binding-type b) 'ellipsis)
|
||
(bound-id=? e (binding-value b))
|
||
(free-id=? e (syntax (... ...))))))))
|
||
|
||
;;; data
|
||
|
||
;;; strips all annotations from potentially circular reader output
|
||
|
||
(define strip-annotation
|
||
(lambda (x parent)
|
||
(cond
|
||
((pair? x)
|
||
(let ((new (cons #f #f)))
|
||
(when parent (set-annotation-stripped! parent new))
|
||
(set-car! new (strip-annotation (car x) #f))
|
||
(set-cdr! new (strip-annotation (cdr x) #f))
|
||
new))
|
||
((annotation? x)
|
||
(or (annotation-stripped x)
|
||
(strip-annotation (annotation-expression x) x)))
|
||
((vector? x)
|
||
(let ((new (make-vector (vector-length x))))
|
||
(when parent (set-annotation-stripped! parent new))
|
||
(let loop ((i (- (vector-length x) 1)))
|
||
(unless (fx< i 0)
|
||
(vector-set! new i (strip-annotation (vector-ref x i) #f))
|
||
(loop (fx- i 1))))
|
||
new))
|
||
(else x))))
|
||
|
||
;;; strips syntax-objects down to top-wrap; if top-wrap is layered directly
|
||
;;; on an annotation, strips the annotation as well.
|
||
;;; since only the head of a list is annotated by the reader, not each pair
|
||
;;; in the spine, we also check for pairs whose cars are annotated in case
|
||
;;; we've been passed the cdr of an annotated list
|
||
|
||
(define strip
|
||
(lambda (x w)
|
||
(if (top-marked? w)
|
||
(if (or (annotation? x) (and (pair? x) (annotation? (car x))))
|
||
(strip-annotation x #f)
|
||
x)
|
||
(let f ((x x))
|
||
(cond
|
||
((syntax-object? x)
|
||
(strip (syntax-object-expression x) (syntax-object-wrap x)))
|
||
((pair? x)
|
||
(let ((a (f (car x))) (d (f (cdr x))))
|
||
(if (and (eq? a (car x)) (eq? d (cdr x)))
|
||
x
|
||
(cons a d))))
|
||
((vector? x)
|
||
(let ((old (vector->list x)))
|
||
(let ((new (map f old)))
|
||
(if (andmap eq? old new) x (list->vector new)))))
|
||
(else x))))))
|
||
|
||
;;; lexical variables
|
||
|
||
(define gen-var
|
||
(lambda (id)
|
||
(let ((id (if (syntax-object? id) (syntax-object-expression id) id)))
|
||
(if (annotation? id)
|
||
(build-lexical-var (annotation-source id) (annotation-expression id))
|
||
(build-lexical-var no-source id)))))
|
||
|
||
(define lambda-var-list
|
||
(lambda (vars)
|
||
(let lvl ((vars vars) (ls '()) (w empty-wrap))
|
||
(cond
|
||
((pair? vars) (lvl (cdr vars) (cons (wrap (car vars) w) ls) w))
|
||
((id? vars) (cons (wrap vars w) ls))
|
||
((null? vars) ls)
|
||
((syntax-object? vars)
|
||
(lvl (syntax-object-expression vars)
|
||
ls
|
||
(join-wraps w (syntax-object-wrap vars))))
|
||
((annotation? vars)
|
||
(lvl (annotation-expression vars) ls w))
|
||
; include anything else to be caught by subsequent error
|
||
; checking
|
||
(else (cons vars ls))))))
|
||
|
||
;;; core transformers
|
||
|
||
(global-extend 'local-syntax 'letrec-syntax #t)
|
||
(global-extend 'local-syntax 'let-syntax #f)
|
||
|
||
(global-extend 'core 'fluid-let-syntax
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ ((var val) ...) e1 e2 ...)
|
||
(valid-bound-ids? (syntax (var ...)))
|
||
(let ((names (map (lambda (x) (id-var-name x w)) (syntax (var ...)))))
|
||
(for-each
|
||
(lambda (id n)
|
||
(case (binding-type (lookup n r))
|
||
((displaced-lexical)
|
||
(syntax-error (source-wrap id w s)
|
||
"identifier out of context"))))
|
||
(syntax (var ...))
|
||
names)
|
||
(chi-body
|
||
(syntax (e1 e2 ...))
|
||
(source-wrap e w s)
|
||
(extend-env
|
||
names
|
||
(let ((trans-r (macros-only-env r)))
|
||
(map (lambda (x)
|
||
(make-binding 'macro
|
||
(eval-local-transformer (chi x trans-r w))))
|
||
(syntax (val ...))))
|
||
r)
|
||
w)))
|
||
(_ (syntax-error (source-wrap e w s))))))
|
||
|
||
(global-extend 'core 'quote
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ e) (build-data s (strip (syntax e) w)))
|
||
(_ (syntax-error (source-wrap e w s))))))
|
||
|
||
(global-extend 'core 'syntax
|
||
(let ()
|
||
(define gen-syntax
|
||
(lambda (src e r maps ellipsis?)
|
||
(if (id? e)
|
||
(let ((label (id-var-name e empty-wrap)))
|
||
(let ((b (lookup label r)))
|
||
(if (eq? (binding-type b) 'syntax)
|
||
(call-with-values
|
||
(lambda ()
|
||
(let ((var.lev (binding-value b)))
|
||
(gen-ref src (car var.lev) (cdr var.lev) maps)))
|
||
(lambda (var maps) (values `(ref ,var) maps)))
|
||
(if (ellipsis? e r)
|
||
(syntax-error src "misplaced ellipsis in syntax form")
|
||
(values `(quote ,e) maps)))))
|
||
(syntax-case e ()
|
||
((dots e)
|
||
(ellipsis? (syntax dots) r)
|
||
(gen-syntax src (syntax e) r maps (lambda (e r) #f)))
|
||
((x dots . y)
|
||
; this could be about a dozen lines of code, except that we
|
||
; choose to handle (syntax (x ... ...)) forms
|
||
(ellipsis? (syntax dots) r)
|
||
(let f ((y (syntax y))
|
||
(k (lambda (maps)
|
||
(call-with-values
|
||
(lambda ()
|
||
(gen-syntax src (syntax x) r
|
||
(cons '() maps) ellipsis?))
|
||
(lambda (x maps)
|
||
(if (null? (car maps))
|
||
(syntax-error src
|
||
"extra ellipsis in syntax form")
|
||
(values (gen-map x (car maps))
|
||
(cdr maps))))))))
|
||
(syntax-case y ()
|
||
((dots . y)
|
||
(ellipsis? (syntax dots) r)
|
||
(f (syntax y)
|
||
(lambda (maps)
|
||
(call-with-values
|
||
(lambda () (k (cons '() maps)))
|
||
(lambda (x maps)
|
||
(if (null? (car maps))
|
||
(syntax-error src
|
||
"extra ellipsis in syntax form")
|
||
(values (gen-mappend x (car maps))
|
||
(cdr maps))))))))
|
||
(_ (call-with-values
|
||
(lambda () (gen-syntax src y r maps ellipsis?))
|
||
(lambda (y maps)
|
||
(call-with-values
|
||
(lambda () (k maps))
|
||
(lambda (x maps)
|
||
(values (gen-append x y) maps)))))))))
|
||
((x . y)
|
||
(call-with-values
|
||
(lambda () (gen-syntax src (syntax x) r maps ellipsis?))
|
||
(lambda (x maps)
|
||
(call-with-values
|
||
(lambda () (gen-syntax src (syntax y) r maps ellipsis?))
|
||
(lambda (y maps) (values (gen-cons x y) maps))))))
|
||
(#(e1 e2 ...)
|
||
(call-with-values
|
||
(lambda ()
|
||
(gen-syntax src (syntax (e1 e2 ...)) r maps ellipsis?))
|
||
(lambda (e maps) (values (gen-vector e) maps))))
|
||
(_ (values `(quote ,e) maps))))))
|
||
|
||
(define gen-ref
|
||
(lambda (src var level maps)
|
||
(if (fx= level 0)
|
||
(values var maps)
|
||
(if (null? maps)
|
||
(syntax-error src "missing ellipsis in syntax form")
|
||
(call-with-values
|
||
(lambda () (gen-ref src var (fx- level 1) (cdr maps)))
|
||
(lambda (outer-var outer-maps)
|
||
(let ((b (assq outer-var (car maps))))
|
||
(if b
|
||
(values (cdr b) maps)
|
||
(let ((inner-var (gen-var 'tmp)))
|
||
(values inner-var
|
||
(cons (cons (cons outer-var inner-var)
|
||
(car maps))
|
||
outer-maps)))))))))))
|
||
|
||
(define gen-mappend
|
||
(lambda (e map-env)
|
||
`(apply (primitive append) ,(gen-map e map-env))))
|
||
|
||
(define gen-map
|
||
(lambda (e map-env)
|
||
(let ((formals (map cdr map-env))
|
||
(actuals (map (lambda (x) `(ref ,(car x))) map-env)))
|
||
(cond
|
||
((eq? (car e) 'ref)
|
||
; identity map equivalence:
|
||
; (map (lambda (x) x) y) == y
|
||
(car actuals))
|
||
((andmap
|
||
(lambda (x) (and (eq? (car x) 'ref) (memq (cadr x) formals)))
|
||
(cdr e))
|
||
; eta map equivalence:
|
||
; (map (lambda (x ...) (f x ...)) y ...) == (map f y ...)
|
||
`(map (primitive ,(car e))
|
||
,@(map (let ((r (map cons formals actuals)))
|
||
(lambda (x) (cdr (assq (cadr x) r))))
|
||
(cdr e))))
|
||
(else `(map (lambda ,formals ,e) ,@actuals))))))
|
||
|
||
(define gen-cons
|
||
(lambda (x y)
|
||
(case (car y)
|
||
((quote)
|
||
(if (eq? (car x) 'quote)
|
||
`(quote (,(cadr x) . ,(cadr y)))
|
||
(if (eq? (cadr y) '())
|
||
`(list ,x)
|
||
`(cons ,x ,y))))
|
||
((list) `(list ,x ,@(cdr y)))
|
||
(else `(cons ,x ,y)))))
|
||
|
||
(define gen-append
|
||
(lambda (x y)
|
||
(if (equal? y '(quote ()))
|
||
x
|
||
`(append ,x ,y))))
|
||
|
||
(define gen-vector
|
||
(lambda (x)
|
||
(cond
|
||
((eq? (car x) 'list) `(vector ,@(cdr x)))
|
||
((eq? (car x) 'quote) `(quote #(,@(cadr x))))
|
||
(else `(list->vector ,x)))))
|
||
|
||
|
||
(define regen
|
||
(lambda (x)
|
||
(case (car x)
|
||
((ref) (build-lexical-reference 'value no-source (cadr x)))
|
||
((primitive) (build-primref no-source (cadr x)))
|
||
((quote) (build-data no-source (cadr x)))
|
||
((lambda) (build-lambda no-source (cadr x) (regen (caddr x))))
|
||
((map) (let ((ls (map regen (cdr x))))
|
||
(build-application no-source
|
||
(if (fx= (length ls) 2)
|
||
(build-primref no-source 'map)
|
||
; really need to do our own checking here
|
||
(build-primref no-source 2 'map)) ; require error check
|
||
ls)))
|
||
(else (build-application no-source
|
||
(build-primref no-source (car x))
|
||
(map regen (cdr x)))))))
|
||
|
||
(lambda (e r w s)
|
||
(let ((e (source-wrap e w s)))
|
||
(syntax-case e ()
|
||
((_ x)
|
||
(call-with-values
|
||
(lambda () (gen-syntax e (syntax x) r '() ellipsis?))
|
||
(lambda (e maps) (regen e))))
|
||
(_ (syntax-error e)))))))
|
||
|
||
|
||
(global-extend 'core 'lambda
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ . c)
|
||
(chi-lambda-clause (source-wrap e w s) (syntax c) r w
|
||
(lambda (vars body) (build-lambda s vars body)))))))
|
||
|
||
|
||
(global-extend 'core 'with-ellipsis
|
||
(lambda (e r w s)
|
||
(let* ((tmp e) (tmp (syntax-dispatch tmp '(_ any any . each-any))))
|
||
(if (and tmp (apply (lambda (dots e1 e2) (id? dots)) tmp))
|
||
(apply (lambda (dots e1 e2)
|
||
(let ((id (if (symbol? dots)
|
||
'$sc-ellipsis
|
||
(make-syntax-object
|
||
'$sc-ellipsis
|
||
(syntax-object-wrap dots)))))
|
||
(let ((ids (list id))
|
||
(labels (list (gen-label)))
|
||
(bindings (list (cons 'ellipsis (source-wrap dots w s)))))
|
||
(let ((nw (make-binding-wrap ids labels w))
|
||
(nr (extend-env labels bindings r)))
|
||
(chi-body (cons e1 e2) (source-wrap e nw s) nr nw)))))
|
||
tmp)
|
||
(syntax-error 'with-ellipsis "bad syntax")))))
|
||
|
||
(global-extend 'core 'let
|
||
(let ()
|
||
(define (chi-let e r w s constructor ids vals exps)
|
||
(if (not (valid-bound-ids? ids))
|
||
(syntax-error e "duplicate bound variable in")
|
||
(let ((labels (gen-labels ids))
|
||
(new-vars (map gen-var ids)))
|
||
(let ((nw (make-binding-wrap ids labels w))
|
||
(nr (extend-var-env labels new-vars r)))
|
||
(constructor s
|
||
new-vars
|
||
(map (lambda (x) (chi x r w)) vals)
|
||
(chi-body exps (source-wrap e nw s) nr nw))))))
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ ((id val) ...) e1 e2 ...)
|
||
(chi-let e r w s
|
||
build-let
|
||
(syntax (id ...))
|
||
(syntax (val ...))
|
||
(syntax (e1 e2 ...))))
|
||
((_ f ((id val) ...) e1 e2 ...)
|
||
(id? (syntax f))
|
||
(chi-let e r w s
|
||
build-named-let
|
||
(syntax (f id ...))
|
||
(syntax (val ...))
|
||
(syntax (e1 e2 ...))))
|
||
(_ (syntax-error (source-wrap e w s)))))))
|
||
|
||
|
||
(global-extend 'core 'letrec
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ ((id val) ...) e1 e2 ...)
|
||
(let ((ids (syntax (id ...))))
|
||
(if (not (valid-bound-ids? ids))
|
||
(syntax-error e "duplicate bound variable in")
|
||
(let ((labels (gen-labels ids))
|
||
(new-vars (map gen-var ids)))
|
||
(let ((w (make-binding-wrap ids labels w))
|
||
(r (extend-var-env labels new-vars r)))
|
||
(build-letrec s
|
||
new-vars
|
||
(map (lambda (x) (chi x r w)) (syntax (val ...)))
|
||
(chi-body (syntax (e1 e2 ...)) (source-wrap e w s) r w)))))))
|
||
(_ (syntax-error (source-wrap e w s))))))
|
||
|
||
|
||
(global-extend 'core 'set!
|
||
(lambda (e r w s)
|
||
(syntax-case e ()
|
||
((_ id val)
|
||
(id? (syntax id))
|
||
(let ((val (chi (syntax val) r w))
|
||
(n (id-var-name (syntax id) w)))
|
||
(let ((b (lookup n r)))
|
||
(case (binding-type b)
|
||
((lexical)
|
||
(build-lexical-assignment s (binding-value b) val))
|
||
((global) (build-global-assignment s n val))
|
||
((displaced-lexical)
|
||
(syntax-error (wrap (syntax id) w)
|
||
"identifier out of context"))
|
||
(else (syntax-error (source-wrap e w s)))))))
|
||
((_ (getter arg ...) val)
|
||
(build-application s
|
||
(chi (syntax (setter getter)) r w)
|
||
(map (lambda (e) (chi e r w))
|
||
(syntax (arg ... val)))))
|
||
(_ (syntax-error (source-wrap e w s))))))
|
||
|
||
(global-extend 'begin 'begin '())
|
||
|
||
(global-extend 'define 'define '())
|
||
|
||
(global-extend 'define-syntax 'define-syntax '())
|
||
|
||
(global-extend 'eval-when 'eval-when '())
|
||
|
||
(global-extend 'core 'syntax-case
|
||
(let ()
|
||
(define convert-pattern
|
||
; accepts pattern & keys
|
||
; returns syntax-dispatch pattern & ids
|
||
(lambda (pattern keys ellipsis?)
|
||
(let cvt ((p pattern) (n 0) (ids '()))
|
||
(if (id? p)
|
||
(if (bound-id-member? p keys)
|
||
(values (vector 'free-id p) ids)
|
||
(values 'any (cons (cons p n) ids)))
|
||
(syntax-case p ()
|
||
((x dots)
|
||
(ellipsis? (syntax dots))
|
||
(call-with-values
|
||
(lambda () (cvt (syntax x) (fx+ n 1) ids))
|
||
(lambda (p ids)
|
||
(values (if (eq? p 'any) 'each-any (vector 'each p))
|
||
ids))))
|
||
((x . y)
|
||
(call-with-values
|
||
(lambda () (cvt (syntax y) n ids))
|
||
(lambda (y ids)
|
||
(call-with-values
|
||
(lambda () (cvt (syntax x) n ids))
|
||
(lambda (x ids)
|
||
(values (cons x y) ids))))))
|
||
(() (values '() ids))
|
||
(#(x ...)
|
||
(call-with-values
|
||
(lambda () (cvt (syntax (x ...)) n ids))
|
||
(lambda (p ids) (values (vector 'vector p) ids))))
|
||
(x (values (vector 'atom (strip p empty-wrap)) ids)))))))
|
||
|
||
(define build-dispatch-call
|
||
(lambda (pvars exp y r)
|
||
(let ((ids (map car pvars)) (levels (map cdr pvars)))
|
||
(let ((labels (gen-labels ids)) (new-vars (map gen-var ids)))
|
||
(build-application no-source
|
||
(build-primref no-source 'apply)
|
||
(list (build-lambda no-source new-vars
|
||
(chi exp
|
||
(extend-env
|
||
labels
|
||
(map (lambda (var level)
|
||
(make-binding 'syntax `(,var . ,level)))
|
||
new-vars
|
||
(map cdr pvars))
|
||
r)
|
||
(make-binding-wrap ids labels empty-wrap)))
|
||
y))))))
|
||
|
||
(define gen-clause
|
||
(lambda (x keys clauses r pat fender exp)
|
||
(call-with-values
|
||
(lambda () (convert-pattern pat keys (lambda (e) (ellipsis? e r))))
|
||
(lambda (p pvars)
|
||
(cond
|
||
((not (distinct-bound-ids? (map car pvars)))
|
||
(syntax-error pat
|
||
"duplicate pattern variable in syntax-case pattern"))
|
||
((not (andmap (lambda (x) (not (ellipsis? (car x) r))) pvars))
|
||
(syntax-error pat
|
||
"misplaced ellipsis in syntax-case pattern"))
|
||
(else
|
||
(let ((y (gen-var 'tmp)))
|
||
; fat finger binding and references to temp variable y
|
||
(build-application no-source
|
||
(build-lambda no-source (list y)
|
||
(let ((y (build-lexical-reference 'value no-source y)))
|
||
(build-conditional no-source
|
||
(syntax-case fender ()
|
||
(#t y)
|
||
(_ (build-conditional no-source
|
||
y
|
||
(build-dispatch-call pvars fender y r)
|
||
(build-data no-source #f))))
|
||
(build-dispatch-call pvars exp y r)
|
||
(gen-syntax-case x keys clauses r))))
|
||
(list (if (eq? p 'any)
|
||
(build-application no-source
|
||
(build-primref no-source 'list)
|
||
(list x))
|
||
(build-application no-source
|
||
(build-primref no-source 'syntax-dispatch)
|
||
(list x (build-data no-source p)))))))))))))
|
||
|
||
(define gen-syntax-case
|
||
(lambda (x keys clauses r)
|
||
(if (null? clauses)
|
||
(build-application no-source
|
||
(build-primref no-source 'syntax-error)
|
||
(list x))
|
||
(syntax-case (car clauses) ()
|
||
((pat exp)
|
||
(if (and (id? (syntax pat))
|
||
(andmap (lambda (x) (not (free-id=? (syntax pat) x)))
|
||
(cons (syntax (... ...)) keys)))
|
||
(let ((labels (list (gen-label)))
|
||
(var (gen-var (syntax pat))))
|
||
(build-application no-source
|
||
(build-lambda no-source (list var)
|
||
(chi (syntax exp)
|
||
(extend-env labels
|
||
(list (make-binding 'syntax `(,var . 0)))
|
||
r)
|
||
(make-binding-wrap (syntax (pat))
|
||
labels empty-wrap)))
|
||
(list x)))
|
||
(gen-clause x keys (cdr clauses) r
|
||
(syntax pat) #t (syntax exp))))
|
||
((pat fender exp)
|
||
(gen-clause x keys (cdr clauses) r
|
||
(syntax pat) (syntax fender) (syntax exp)))
|
||
(_ (syntax-error (car clauses) "invalid syntax-case clause"))))))
|
||
|
||
(lambda (e r w s)
|
||
(let ((e (source-wrap e w s)))
|
||
(syntax-case e ()
|
||
((_ val (key ...) m ...)
|
||
(if (andmap (lambda (x) (and (id? x) (not (ellipsis? x r))))
|
||
(syntax (key ...)))
|
||
(let ((x (gen-var 'tmp)))
|
||
; fat finger binding and references to temp variable x
|
||
(build-application s
|
||
(build-lambda no-source (list x)
|
||
(gen-syntax-case (build-lexical-reference 'value no-source x)
|
||
(syntax (key ...)) (syntax (m ...))
|
||
r))
|
||
(list (chi (syntax val) r empty-wrap))))
|
||
(syntax-error e "invalid literals list in"))))))))
|
||
|
||
;;; The portable sc-expand seeds chi-top's mode m with 'e (for
|
||
;;; evaluating) and esew (which stands for "eval syntax expanders
|
||
;;; when") with '(eval). In Chez Scheme, m is set to 'c instead of e
|
||
;;; if we are compiling a file, and esew is set to
|
||
;;; (eval-syntactic-expanders-when), which defaults to the list
|
||
;;; '(compile load eval). This means that, by default, top-level
|
||
;;; syntactic definitions are evaluated immediately after they are
|
||
;;; expanded, and the expanded definitions are also residualized into
|
||
;;; the object file if we are compiling a file.
|
||
(set! sc-expand
|
||
(let ((m 'e) (esew '(eval)))
|
||
(lambda (x)
|
||
(if (and (pair? x) (equal? (car x) noexpand))
|
||
(cadr x)
|
||
(chi-top x null-env top-wrap m esew)))))
|
||
|
||
(set! sc-expand3
|
||
(let ((m 'e) (esew '(eval)))
|
||
(lambda (x . rest)
|
||
(if (and (pair? x) (equal? (car x) noexpand))
|
||
(cadr x)
|
||
(chi-top x
|
||
null-env
|
||
top-wrap
|
||
(if (null? rest) m (car rest))
|
||
(if (or (null? rest) (null? (cdr rest)))
|
||
esew
|
||
(cadr rest)))))))
|
||
|
||
(set! identifier?
|
||
(lambda (x)
|
||
(nonsymbol-id? x)))
|
||
|
||
(set! datum->syntax-object
|
||
(lambda (id datum)
|
||
(make-syntax-object datum (syntax-object-wrap id))))
|
||
|
||
(set! syntax-object->datum
|
||
; accepts any object, since syntax objects may consist partially
|
||
; or entirely of unwrapped, nonsymbolic data
|
||
(lambda (x)
|
||
(strip x empty-wrap)))
|
||
|
||
(set! generate-temporaries
|
||
(lambda (ls)
|
||
(arg-check list? ls 'generate-temporaries)
|
||
(map (lambda (x) (wrap (gensym-hook) top-wrap)) ls)))
|
||
|
||
(set! free-identifier=?
|
||
(lambda (x y)
|
||
(arg-check nonsymbol-id? x 'free-identifier=?)
|
||
(arg-check nonsymbol-id? y 'free-identifier=?)
|
||
(free-id=? x y)))
|
||
|
||
(set! bound-identifier=?
|
||
(lambda (x y)
|
||
(arg-check nonsymbol-id? x 'bound-identifier=?)
|
||
(arg-check nonsymbol-id? y 'bound-identifier=?)
|
||
(bound-id=? x y)))
|
||
|
||
(set! syntax-error
|
||
(lambda (object . messages)
|
||
(for-each (lambda (x) (arg-check string? x 'syntax-error)) messages)
|
||
(let ((message (if (null? messages)
|
||
"invalid syntax"
|
||
(apply string-append messages))))
|
||
(error-hook #f message (strip object empty-wrap)))))
|
||
|
||
(set! install-global-transformer
|
||
(lambda (sym v)
|
||
(arg-check symbol? sym 'define-syntax)
|
||
(arg-check procedure? v 'define-syntax)
|
||
(global-extend 'macro sym v)))
|
||
|
||
;;; syntax-dispatch expects an expression and a pattern. If the expression
|
||
;;; matches the pattern a list of the matching expressions for each
|
||
;;; "any" is returned. Otherwise, #f is returned. (This use of #f will
|
||
;;; not work on r4rs implementations that violate the ieee requirement
|
||
;;; that #f and () be distinct.)
|
||
|
||
;;; The expression is matched with the pattern as follows:
|
||
|
||
;;; pattern: matches:
|
||
;;; () empty list
|
||
;;; any anything
|
||
;;; (<pattern>1 . <pattern>2) (<pattern>1 . <pattern>2)
|
||
;;; each-any (any*)
|
||
;;; #(free-id <key>) <key> with free-identifier=?
|
||
;;; #(each <pattern>) (<pattern>*)
|
||
;;; #(vector <pattern>) (list->vector <pattern>)
|
||
;;; #(atom <object>) <object> with "equal?"
|
||
|
||
;;; Vector cops out to pair under assumption that vectors are rare. If
|
||
;;; not, should convert to:
|
||
;;; #(vector <pattern>*) #(<pattern>*)
|
||
|
||
(let ()
|
||
|
||
(define match-each
|
||
(lambda (e p w)
|
||
(cond
|
||
((annotation? e)
|
||
(match-each (annotation-expression e) p w))
|
||
((pair? e)
|
||
(let ((first (match (car e) p w '())))
|
||
(and first
|
||
(let ((rest (match-each (cdr e) p w)))
|
||
(and rest (cons first rest))))))
|
||
((null? e) '())
|
||
((syntax-object? e)
|
||
(match-each (syntax-object-expression e)
|
||
p
|
||
(join-wraps w (syntax-object-wrap e))))
|
||
(else #f))))
|
||
|
||
(define match-each-any
|
||
(lambda (e w)
|
||
(cond
|
||
((annotation? e)
|
||
(match-each-any (annotation-expression e) w))
|
||
((pair? e)
|
||
(let ((l (match-each-any (cdr e) w)))
|
||
(and l (cons (wrap (car e) w) l))))
|
||
((null? e) '())
|
||
((syntax-object? e)
|
||
(match-each-any (syntax-object-expression e)
|
||
(join-wraps w (syntax-object-wrap e))))
|
||
(else #f))))
|
||
|
||
(define match-empty
|
||
(lambda (p r)
|
||
(cond
|
||
((null? p) r)
|
||
((eq? p '_) r)
|
||
((eq? p 'any) (cons '() r))
|
||
((pair? p) (match-empty (car p) (match-empty (cdr p) r)))
|
||
((eq? p 'each-any) (cons '() r))
|
||
(else
|
||
(case (vector-ref p 0)
|
||
((each) (match-empty (vector-ref p 1) r))
|
||
((free-id atom) r)
|
||
((vector) (match-empty (vector-ref p 1) r)))))))
|
||
|
||
(define match*
|
||
(lambda (e p w r)
|
||
(cond
|
||
((null? p) (and (null? e) r))
|
||
((pair? p)
|
||
(and (pair? e) (match (car e) (car p) w
|
||
(match (cdr e) (cdr p) w r))))
|
||
((eq? p 'each-any)
|
||
(let ((l (match-each-any e w))) (and l (cons l r))))
|
||
(else
|
||
(case (vector-ref p 0)
|
||
((each)
|
||
(if (null? e)
|
||
(match-empty (vector-ref p 1) r)
|
||
(let ((l (match-each e (vector-ref p 1) w)))
|
||
(and l
|
||
(let collect ((l l))
|
||
(if (null? (car l))
|
||
r
|
||
(cons (map car l) (collect (map cdr l)))))))))
|
||
((free-id) (and (id? e) (free-id=? (wrap e w) (vector-ref p 1)) r))
|
||
((atom) (and (equal? (vector-ref p 1) (strip e w)) r))
|
||
((vector)
|
||
(and (vector? e)
|
||
(match (vector->list e) (vector-ref p 1) w r))))))))
|
||
|
||
(define match
|
||
(lambda (e p w r)
|
||
(cond
|
||
((not r) #f)
|
||
((eq? p '_) r)
|
||
((eq? p 'any) (cons (wrap e w) r))
|
||
((syntax-object? e)
|
||
(match*
|
||
(unannotate (syntax-object-expression e))
|
||
p
|
||
(join-wraps w (syntax-object-wrap e))
|
||
r))
|
||
(else (match* (unannotate e) p w r)))))
|
||
|
||
(set! syntax-dispatch
|
||
(lambda (e p)
|
||
(cond
|
||
((eq? p 'any) (list e))
|
||
((eq? p '_) '())
|
||
((syntax-object? e)
|
||
(match* (unannotate (syntax-object-expression e))
|
||
p (syntax-object-wrap e) '()))
|
||
(else (match* (unannotate e) p empty-wrap '())))))
|
||
|
||
(set! sc-chi chi)
|
||
))
|
||
)
|
||
|
||
(define-syntax with-syntax
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ () e1 e2 ...)
|
||
(syntax (let () e1 e2 ...)))
|
||
((_ ((out in)) e1 e2 ...)
|
||
(syntax (syntax-case in () (out (let () e1 e2 ...)))))
|
||
((_ ((out in) ...) e1 e2 ...)
|
||
(syntax (syntax-case (list in ...) ()
|
||
((out ...) (let () e1 e2 ...))))))))
|
||
|
||
(define-syntax syntax-rules
|
||
(lambda (xx)
|
||
(define (expand-syntax-rules dots keys docstrings clauses)
|
||
(with-syntax
|
||
(((k ...) keys)
|
||
((docstring ...) docstrings)
|
||
((((keyword . pattern) template) ...) clauses))
|
||
(with-syntax
|
||
((form (syntax (lambda (x)
|
||
docstring ... ; optional docstring
|
||
;; #((macro-type . syntax-rules)
|
||
;; (patterns pattern ...)) ; embed patterns as procedure metadata
|
||
(syntax-case x (k ...)
|
||
((dummy . pattern) (syntax template))
|
||
...)))))
|
||
(if dots
|
||
(with-syntax ((dots dots))
|
||
(syntax (with-ellipsis dots form)))
|
||
(syntax form)))))
|
||
(syntax-case xx ()
|
||
((_ (k ...) ((keyword . pattern) template) ...)
|
||
(expand-syntax-rules #f (syntax (k ...)) (syntax ()) (syntax (((keyword . pattern) template) ...))))
|
||
((_ (k ...) docstring ((keyword . pattern) template) ...)
|
||
(string? (syntax-object->datum (syntax docstring)))
|
||
(expand-syntax-rules #f (syntax (k ...)) (syntax (docstring)) (syntax (((keyword . pattern) template) ...))))
|
||
((_ dots (k ...) ((keyword . pattern) template) ...)
|
||
(identifier? (syntax dots))
|
||
(expand-syntax-rules (syntax dots) (syntax (k ...)) (syntax ()) (syntax (((keyword . pattern) template) ...))))
|
||
((_ dots (k ...) docstring ((keyword . pattern) template) ...)
|
||
(and (identifier? (syntax dots)) (string? (syntax-object->datum (syntax docstring))))
|
||
(expand-syntax-rules (syntax dots) (syntax (k ...)) (syntax (docstring)) (syntax (((keyword . pattern) template) ...)))))))
|
||
|
||
(define-syntax define-syntax-rule
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ (name . pattern) template)
|
||
(syntax (define-syntax name
|
||
(syntax-rules ()
|
||
((_ . pattern) template)))))
|
||
((_ (name . pattern) docstring template)
|
||
(string? (syntax-object->datum (syntax docstring)))
|
||
(syntax (define-syntax name
|
||
(syntax-rules ()
|
||
docstring
|
||
((_ . pattern) template))))))))
|
||
|
||
(define-syntax let*
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((let* ((x v) ...) e1 e2 ...)
|
||
(andmap identifier? (syntax (x ...)))
|
||
(let f ((bindings (syntax ((x v) ...))))
|
||
(if (null? bindings)
|
||
(syntax (let () e1 e2 ...))
|
||
(with-syntax ((body (f (cdr bindings)))
|
||
(binding (car bindings)))
|
||
(syntax (let (binding) body)))))))))
|
||
|
||
(define-syntax do
|
||
(lambda (orig-x)
|
||
(syntax-case orig-x ()
|
||
((_ ((var init . step) ...) (e0 e1 ...) c ...)
|
||
(with-syntax (((step ...)
|
||
(map (lambda (v s)
|
||
(syntax-case s ()
|
||
(() v)
|
||
((e) (syntax e))
|
||
(_ (syntax-error orig-x))))
|
||
(syntax (var ...))
|
||
(syntax (step ...)))))
|
||
(syntax-case (syntax (e1 ...)) ()
|
||
(() (syntax (let doloop ((var init) ...)
|
||
(if (not e0)
|
||
(begin c ... (doloop step ...))))))
|
||
((e1 e2 ...)
|
||
(syntax (let doloop ((var init) ...)
|
||
(if e0
|
||
(begin e1 e2 ...)
|
||
(begin c ... (doloop step ...))))))))))))
|
||
|
||
(define-syntax quasiquote
|
||
(letrec
|
||
((quasicons
|
||
(lambda (x y)
|
||
(with-syntax ((x x) (y y))
|
||
(syntax-case (syntax y) (quote list)
|
||
((quote dy)
|
||
(syntax-case (syntax x) (quote)
|
||
((quote dx) (syntax (quote (dx . dy))))
|
||
(_ (if (null? (syntax dy))
|
||
(syntax (list x))
|
||
(syntax (cons x y))))))
|
||
((list . stuff) (syntax (list x . stuff)))
|
||
(else (syntax (cons x y)))))))
|
||
(quasiappend
|
||
(lambda (x y)
|
||
(with-syntax ((x x) (y y))
|
||
(syntax-case (syntax y) (quote)
|
||
((quote ()) (syntax x))
|
||
(_ (syntax (append x y)))))))
|
||
(quasivector
|
||
(lambda (x)
|
||
(with-syntax ((x x))
|
||
(syntax-case (syntax x) (quote list)
|
||
((quote (x ...)) (syntax (quote #(x ...))))
|
||
((list x ...) (syntax (vector x ...)))
|
||
(_ (syntax (list->vector x)))))))
|
||
(quasi
|
||
(lambda (p lev)
|
||
(syntax-case p (unquote unquote-splicing quasiquote)
|
||
((unquote p)
|
||
(if (= lev 0)
|
||
(syntax p)
|
||
(quasicons (syntax (quote unquote))
|
||
(quasi (syntax (p)) (- lev 1)))))
|
||
(((unquote-splicing p) . q)
|
||
(if (= lev 0)
|
||
(quasiappend (syntax p) (quasi (syntax q) lev))
|
||
(quasicons (quasicons (syntax (quote unquote-splicing))
|
||
(quasi (syntax (p)) (- lev 1)))
|
||
(quasi (syntax q) lev))))
|
||
((quasiquote p)
|
||
(quasicons (syntax (quote quasiquote))
|
||
(quasi (syntax (p)) (+ lev 1))))
|
||
((p . q)
|
||
(quasicons (quasi (syntax p) lev) (quasi (syntax q) lev)))
|
||
(#(x ...) (quasivector (quasi (syntax (x ...)) lev)))
|
||
(p (syntax (quote p)))))))
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ e) (quasi (syntax e) 0))))))
|
||
|
||
(define-syntax include
|
||
(lambda (x)
|
||
(define read-file
|
||
(lambda (fn k)
|
||
(let ((p (open-input-file fn)))
|
||
(let f ((x (read p)))
|
||
(if (eof-object? x)
|
||
(begin (close-input-port p) '())
|
||
(cons (datum->syntax-object k x)
|
||
(f (read p))))))))
|
||
(syntax-case x ()
|
||
((k filename)
|
||
(let ((fn (syntax-object->datum (syntax filename))))
|
||
(with-syntax (((exp ...) (read-file fn (syntax k))))
|
||
(syntax (begin exp ...))))))))
|
||
|
||
(define-syntax unquote
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ e)
|
||
(error 'unquote
|
||
"expression ,~s not valid outside of quasiquote"
|
||
(syntax-object->datum (syntax e)))))))
|
||
|
||
(define-syntax unquote-splicing
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ e)
|
||
(error 'unquote-splicing
|
||
"expression ,@~s not valid outside of quasiquote"
|
||
(syntax-object->datum (syntax e)))))))
|
||
|
||
(define-syntax case
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ e m1 m2 ...)
|
||
(with-syntax
|
||
((body (let f ((clause (syntax m1)) (clauses (syntax (m2 ...))))
|
||
(if (null? clauses)
|
||
(syntax-case clause (else)
|
||
((else e1 e2 ...) (syntax (begin e1 e2 ...)))
|
||
(((k ...) e1 e2 ...)
|
||
(syntax (if (memv t '(k ...)) (begin e1 e2 ...))))
|
||
(_ (syntax-error x)))
|
||
(with-syntax ((rest (f (car clauses) (cdr clauses))))
|
||
(syntax-case clause (else)
|
||
(((k ...) e1 e2 ...)
|
||
(syntax (if (memv t '(k ...))
|
||
(begin e1 e2 ...)
|
||
rest)))
|
||
(_ (syntax-error x))))))))
|
||
(syntax (let ((t e)) body)))))))
|
||
|
||
(define-syntax identifier-syntax
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
((_ e)
|
||
(syntax
|
||
(lambda (x)
|
||
(syntax-case x ()
|
||
(id
|
||
(identifier? (syntax id))
|
||
(syntax e))
|
||
((_ x (... ...))
|
||
(syntax (e x (... ...)))))))))))
|