+++ /dev/null
-;;; Portable implementation of syntax-case
-;;; Extracted from Chez Scheme Version 5.9f
-;;; Authors: R. Kent Dybvig, Oscar Waddell, Bob Hieb, Carl Bruggeman
-
-;;; Copyright (c) 1992-1997 Cadence Research Systems
-;;; 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
-;;; is provided AS IS, with NO WARRANTY, EITHER EXPRESS OR IMPLIED,
-;;; INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY
-;;; OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL THE
-;;; AUTHORS BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES OF ANY
-;;; NATURE WHATSOEVER.
-
-
-;;; Before attempting to port this code to a new implementation of
-;;; Scheme, please read the notes below carefully.
-
-
-;;; This file defines the syntax-case expander, sc-expand, and a set
-;;; of associated syntactic forms and procedures. Of these, the
-;;; following are documented in The Scheme Programming Language,
-;;; Second Edition (R. Kent Dybvig, Prentice Hall, 1996). Most are
-;;; also documented in the R4RS and draft R5RS.
-;;;
-;;; bound-identifier=?
-;;; datum->syntax-object
-;;; define-syntax
-;;; fluid-let-syntax
-;;; free-identifier=?
-;;; generate-temporaries
-;;; identifier?
-;;; identifier-syntax
-;;; let-syntax
-;;; letrec-syntax
-;;; syntax
-;;; syntax-case
-;;; syntax-object->datum
-;;; syntax-rules
-;;; with-syntax
-;;;
-;;; All standard Scheme syntactic forms are supported by the expander
-;;; or syntactic abstractions defined in this file. Only the R4RS
-;;; delay is omitted, since its expansion is implementation-dependent.
-
-;;; The remaining exports are listed below:
-;;;
-;;; (sc-expand datum)
-;;; if datum represents a valid expression, sc-expand returns an
-;;; expanded version of datum in a core language that includes no
-;;; syntactic abstractions. The core language includes begin,
-;;; define, if, lambda, letrec, quote, and set!.
-;;; (eval-when situations expr ...)
-;;; conditionally evaluates expr ... at compile-time or run-time
-;;; 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)
-;;; used by expanded code to install top-level syntactic abstractions
-;;; (syntax-dispatch e p)
-;;; used by expanded code to handle syntax-case matching
-
-;;; The following nonstandard procedures must be provided by the
-;;; implementation for this code to run.
-;;;
-;;; (void)
-;;; returns the implementation's cannonical "unspecified value". This
-;;; usually works: (define void (lambda () (if #f #f))).
-;;;
-;;; (andmap proc list1 list2 ...)
-;;; returns true if proc returns true when applied to each element of list1
-;;; along with the corresponding elements of list2 ....
-;;; The following definition works but does no error checking:
-;;;
-;;; (define andmap
-;;; (lambda (f first . rest)
-;;; (or (null? first)
-;;; (if (null? rest)
-;;; (let andmap ((first first))
-;;; (let ((x (car first)) (first (cdr first)))
-;;; (if (null? first)
-;;; (f x)
-;;; (and (f x) (andmap first)))))
-;;; (let andmap ((first first) (rest rest))
-;;; (let ((x (car first))
-;;; (xr (map car rest))
-;;; (first (cdr first))
-;;; (rest (map cdr rest)))
-;;; (if (null? first)
-;;; (apply f (cons x xr))
-;;; (and (apply f (cons x xr)) (andmap first rest)))))))))
-;;;
-;;; 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.
-;;;
-;;; (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.
-;;;
-;;; 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.
-;;;
-;;; (error who format-string why what)
-;;; 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
-;;;
-;;; "error in <who>: <why> <what>"
-;;;
-;;; (gensym)
-;;; returns a unique symbol each time it's called
-;;;
-;;; (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
-;;; abbreviated to '<datum>. The #' syntax makes programs written
-;;; using syntax-case shorter and more readable and draws out the
-;;; 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))))
-;;; (define-syntax top-marked?
-;;; (syntax-rules ()
-;;; ((_ w) (memq 'top (wrap-marks w)))))
-;;; rather than
-;;; (define top-wrap '((top)))
-;;; (define top-marked?
-;;; (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.
-
-
-;;; 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,
-;;; annotation-source, annotation-stripped, and set-annotation-stripped!
-;;; 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
-;;; them as not lexically bound.
-
-
-
-(let ()
-(define-syntax define-structure
- (lambda (x)
- (define construct-name
- (lambda (template-identifier . args)
- (datum->syntax-object
- template-identifier
- (string->symbol
- (apply string-append
- (map (lambda (x)
- (if (string? x)
- x
- (symbol->string (syntax-object->datum x))))
- args))))))
- (syntax-case x ()
- ((_ (name id1 ...))
- (andmap identifier? (syntax (name id1 ...)))
- (with-syntax
- ((constructor (construct-name (syntax name) "make-" (syntax name)))
- (predicate (construct-name (syntax name) (syntax name) "?"))
- ((access ...)
- (map (lambda (x) (construct-name x (syntax name) "-" x))
- (syntax (id1 ...))))
- ((assign ...)
- (map (lambda (x)
- (construct-name x "set-" (syntax name) "-" x "!"))
- (syntax (id1 ...))))
- (structure-length
- (+ (length (syntax (id1 ...))) 1))
- ((index ...)
- (let f ((i 1) (ids (syntax (id1 ...))))
- (if (null? ids)
- '()
- (cons i (f (+ i 1) (cdr ids)))))))
- (syntax (begin
- (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))))
-
-(define local-eval-hook
- (lambda (x)
- (eval `(,noexpand ,x))))
-
-(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-syntax build-data
- (syntax-rules ()
- ((_ src exp) `',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 id generated-symbols))))
-
-(define-syntax self-evaluating?
- (syntax-rules ()
- ((_ e)
- (let ((x e))
- (or (boolean? x) (number? x) (string? x) (char? x) (null? x) (keyword? x))))))
-)
-
-(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
-;;; (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 (eq? (cadr a) 'macro)
- (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)
-;;; 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) (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))))
- (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)))
- (case (binding-type (lookup n r))
- ((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 (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) (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 transfomer")))))
-
-(define chi-void
- (lambda ()
- (build-application no-source (build-primref no-source 'void) '())))
-
-(define ellipsis?
- (lambda (x)
- (and (nonsymbol-id? x)
- (free-id=? x (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)
- (syntax-error src "misplaced ellipsis in syntax form")
- (values `(quote ,e) maps)))))
- (syntax-case e ()
- ((dots e)
- (ellipsis? (syntax dots))
- (gen-syntax src (syntax e) r maps (lambda (x) #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))
- (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))
- (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 '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)))))))
- (_ (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)
- (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 (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)))) 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))))
- (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)
- (arg-check nonsymbol-id? id 'datum->syntax-object)
- (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 '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 '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))
- ((syntax-object? e)
- (match* (unannotate (syntax-object-expression e))
- p (syntax-object-wrap e) '()))
- (else (match* (unannotate e) p empty-wrap '())))))
-))
-)
-
-(define-syntax with-syntax
- (lambda (x)
- (syntax-case x ()
- ((_ () e1 e2 ...)
- (syntax (begin e1 e2 ...)))
- ((_ ((out in)) e1 e2 ...)
- (syntax (syntax-case in () (out (begin e1 e2 ...)))))
- ((_ ((out in) ...) e1 e2 ...)
- (syntax (syntax-case (list in ...) ()
- ((out ...) (begin e1 e2 ...))))))))
-
-(define-syntax syntax-rules
- (lambda (x)
- (syntax-case x ()
- ((_ (k ...) ((keyword . pattern) template) ...)
- (syntax (lambda (x)
- (syntax-case x (k ...)
- ((dummy . pattern) (syntax 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 (... ...)))))))))))
-
HCoop / bpt / guile.git / commitdiff