Hello all,
I try to write a small module language (named: biglooModuleSyntax.scm)
in order to be able to run some files with a bigloo module statement in
Racket. However, I run into a problem I do not understand at all.
The (Bigloo) code loads a library ssax-sxml. In Racket, this must be
replaced by: (require (planet "sxml.ss" ("lizorkin" "sxml.plt" 2 1))).
The Bigloo code also needs some extra functions not provided by sxml.ss,
so I require an additional small module (in missing-ssax-functions.scm).
To this end, biglooModuleSyntax.scm contains the following macro:
(define-syntax library
(syntax-rules ()
[(library ssax-sxml)
(begin
(require (planet "sxml.ss" ("lizorkin" "sxml.plt" 2 1)))
(require "missing-ssax-functions.scm")
)
]
))
This, however, does not produce the desired results, as shown below. Now
there is another macro in biglooModuleSyntax.scm that handles (some)
import forms::
(define-syntax import
(syntax-rules ()
[(import (moduleName path))
(require path)]
))
and that works just fine. Now here is the problem. The following program
works just fine:
;works.scm
#lang s-exp "biglooModuleSyntax.scm"
(module test
(import (missing-ssax-functions "missing-ssax-functions.scm"))
)
(display (SRV:send-reply 1))
where SRV:send-reply is a stub defined in missing-ssax-functions.scm
that just returns its argument (its definition is of no importance
here). However, the next program does NOT work:
;doesNotWork.scm
#lang s-exp "biglooModuleSyntax.scm"
(module test
(library ssax-sxml)
)
(display (SRV:send-reply 1))
even if the line requiring the sxml.ss module from Planet is commented out.
Racket complains: expand: unbound identifier in module in: SRV:send-reply.
It is all the more baffling because the macro expansions of both module
statements are almost exactly the same, respectively:
'(begin (#%require "missing-ssax-functions.scm")) ;WORKS
and
'(begin (begin (#%require "missing-ssax-functions.scm"))) ;DOES NOT WORK
Replacing the module statements with either of the expansions makes the
program(s) run as expected.
What is going on?
I would really appreciate help!
Please find the complete sources below.
Thanks in advance,
Joop Ringelberg
=============================================== BIGLOOMODULESYNTAX.SCM
#lang racket
;This module provides a bigloo module language.
;It does not aspire to be complete!
(provide import
export
library
option
module
eval
(except-out (all-from-out racket) #%module-begin)
(rename-out [module-begin #%module-begin]))
(define-syntax module-begin
(syntax-rules (module)
[(_ (module ident clause ...)
stmt ...)
(#%module-begin
(module ident clause ...)
stmt ...)]
))
(define-syntax module
(syntax-rules ()
[(module ident clause ...)
(begin
clause ...)]
))
(define-syntax import
(syntax-rules ()
[(import (moduleName path))
(require path)]
))
(define-syntax export
(syntax-rules (macro)
[(export (macro ident ...))
(begin (provide ident) ...)]
[(export (ident arg ...) ...)
(begin
(provide ident) ...)]
[(export ident ...)
(begin (provide ident) ...)]
))
(define-syntax library
(syntax-rules ()
[(library ssax-sxml)
(begin
;(require (planet "sxml.ss" ("lizorkin" "sxml.plt" 2 1)))
(require "missing-ssax-functions.scm")
)
]
))
(define-syntax-rule (option ignore ...)
(begin))
(define-syntax-rule (eval ignore ...)
(begin))
=======================================================MISSING-SSAX-FUNCTIONS.SCM
#lang s-exp "biglooModuleSyntax.scm"
;Defines stubs for some missing ssax functions
(module missing-ssax-functions
(export SRV:send-reply))
(define (SRV:send-reply arg)
arg)
=======================================================WORKS.SCM
#lang s-exp "biglooModuleSyntax.scm"
(module test
(import (missing-ssax-functions "missing-ssax-functions.scm"))
)
(display (SRV:send-reply 1))
=======================================================DOESNOTWORK.SCM
#lang s-exp "biglooModuleSyntax.scm"
(module test
(library ssax-sxml)
)
(display (SRV:send-reply 1))
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