info bigloo

28.7 Library and macros

Bigloo libraries can export macros, expanders, and syntaxes but these must be handled carefully. Macros (these also applies to expanders and syntaxes) exported by modules are not visible by client code. Exported macros have to be placed inside the initialization file. For instance, if we change the definition of bformat.init file for:

(declare-library! 'bformat 
   :version "1.0"
   :srfi '(bformat)
   :basename "bigloobformat"
   :module-init '__bformat
   :module-eval '__make_lib
   :class-init "bigloo.bformat.__bformat"
   :class-eval "bigloo.bformat.__make_lib")

(define-expander BFORMAT
   (lambda (x e)
      (match-case x
         ((?- (? (lambda (s) (and (string? s) (not (string-index s #\%))))) . ?a
)
          `(string-append ,@(cdr x)))
         (else
          `(bformat ,@(map (lambda (x) (e x e)) (cdr x)))))

At compile time the macro BFORMAT will be declared. Hence, we can change the definition of foo.scm for:

(module foo
   (library bformat))

(bigloo-library-path-set! (cons (pwd) (bigloo-library-path)))
(print (BFORMAT "library path: %a" (bigloo-library-path)))

(eval '(library-load 'bformat))
(repl)

This document was generated on October 23, 2011 using texi2html 5.0.