lily/module-scheme.cc

   1 /*
   2   lily/module-scheme.cc -- implement module bindings
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "ly-module.hh"
  10
  11 #include "warn.hh"
  12 #include "main.hh"
  13 #include "std-string.hh"
  14
  15
  16 /*
  17   If a variable is changed in SRC, then DEST doesn't see the
  18   definitions.
  19 */
  20
  21 static SCM
  22 module_define_closure_func (void *closure,
  23                             SCM key,
  24                             SCM val,
  25                             SCM /* result */)
  26 {
  27   SCM module = (SCM) closure;
  28   if (scm_variable_bound_p (val) == SCM_BOOL_T)
  29     scm_module_define (module, key, scm_variable_ref (val));
  30   return SCM_EOL;
  31 }
  32
  33 LY_DEFINE (ly_module_copy, "ly:module-copy",
  34            2, 0, 0, (SCM dest, SCM src),
  35            "Copy all bindings from module @var{src} into @var{dest}.")
  36 {
  37 #define FUNC_NAME __FUNCTION__
  38   SCM_VALIDATE_MODULE (1, src);
  39   scm_internal_hash_fold ((Hash_closure_function) & module_define_closure_func,
  40                           (void *) dest,
  41                           SCM_EOL, SCM_MODULE_OBARRAY (src));
  42   return SCM_UNSPECIFIED;
  43 }
  44
  45 LY_DEFINE (ly_clear_anonymous_modules, "ly:clear-anonymous-modules",
  46            0, 0, 0, (),
  47            "Plug a GUILE 1.6 and 1.7 memory leak by breaking a weak"
  48            " reference pointer cycle explicitly.")
  49 {
  50 #ifdef MODULE_GC_KLUDGE
  51   clear_anonymous_modules ();
  52 #endif
  53
  54   return SCM_UNSPECIFIED;
  55 }
  56
  57 /* Lookup SYM, but don't give error when it is not defined.  */
  58 SCM
  59 ly_module_lookup (SCM module, SCM sym)
  60 {
  61 #define FUNC_NAME __FUNCTION__
  62   SCM_VALIDATE_MODULE (1, module);
  63
  64   return scm_sym2var (sym, scm_module_lookup_closure (module), SCM_BOOL_F);
  65 #undef FUNC_NAME
  66 }
  67
  68 /* Lookup SYM in a list of modules, which do not have to be related.
  69    Return the first instance. */
  70 LY_DEFINE (ly_modules_lookup, "ly:modules-lookup",
  71            2, 1, 0,
  72            (SCM modules, SCM sym, SCM def),
  73            "Look up @var{sym} in the list @var{modules},"
  74            " returning the first occurence.  If not found, return"
  75            " @var{def} or @code{#f} if @var{def} isn't specified.")
  76 {
  77   for (SCM s = modules; scm_is_pair (s); s = scm_cdr (s))
  78     {
  79       SCM mod = scm_car (s);
  80       SCM v = ly_module_lookup (mod, sym);
  81       if (SCM_VARIABLEP (v) && SCM_VARIABLE_REF (v) != SCM_UNDEFINED)
  82         return scm_variable_ref (v);
  83     }
  84
  85   if (def != SCM_UNDEFINED)
  86     return def;
  87   return SCM_BOOL_F;
  88 }