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--2008 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, SCM key, SCM val, SCM result)
  23 {
  24   (void) result;
  25   SCM module = (SCM) closure;
  26   if (scm_variable_bound_p (val) == SCM_BOOL_T)
  27     scm_module_define (module, key, scm_variable_ref (val));
  28   return SCM_EOL;
  29 }
  30
  31 LY_DEFINE (ly_module_copy, "ly:module-copy",
  32            2, 0, 0, (SCM dest, SCM src),
  33            "Copy all bindings from module @var{src} into @var{dest}.")
  34 {
  35 #define FUNC_NAME __FUNCTION__
  36   SCM_VALIDATE_MODULE (1, src);
  37   scm_internal_hash_fold ((Hash_closure_function) & module_define_closure_func,
  38                           (void *) dest,
  39                           SCM_EOL, SCM_MODULE_OBARRAY (src));
  40   return SCM_UNSPECIFIED;
  41 }
  42
  43 LY_DEFINE (ly_clear_anonymous_modules, "ly:clear-anonymous-modules",
  44            0, 0, 0, (),
  45            "Plug a GUILE 1.6 and 1.7 memory leak by breaking a weak"
  46            " reference pointer cycle explicitly.")
  47 {
  48 #ifdef MODULE_GC_KLUDGE
  49   clear_anonymous_modules ();
  50 #endif
  51
  52   return SCM_UNSPECIFIED;
  53 }
  54
  55 /* Lookup SYM, but don't give error when it is not defined.  */
  56 SCM
  57 ly_module_lookup (SCM module, SCM sym)
  58 {
  59 #define FUNC_NAME __FUNCTION__
  60   SCM_VALIDATE_MODULE (1, module);
  61
  62   return scm_sym2var (sym, scm_module_lookup_closure (module), SCM_BOOL_F);
  63 #undef FUNC_NAME
  64 }
  65
  66 /* Lookup SYM in a list of modules, which do not have to be related.
  67    Return the first instance. */
  68 LY_DEFINE (ly_modules_lookup, "ly:modules-lookup",
  69            2, 1, 0,
  70            (SCM modules, SCM sym, SCM def),
  71            "Look up @var{sym} in the list @var{modules},"
  72            " returning the first occurence.  If not found, return"
  73            " @var{def} or @code{#f} if @var{def} isn't specified.")
  74 {
  75   for (SCM s = modules; scm_is_pair (s); s = scm_cdr (s))
  76     {
  77       SCM mod = scm_car (s);
  78       SCM v = ly_module_lookup (mod, sym);
  79       if (SCM_VARIABLEP (v) && SCM_VARIABLE_REF (v) != SCM_UNDEFINED)
  80         return scm_variable_ref (v);
  81     }
  82
  83   if (def != SCM_UNDEFINED)
  84     return def;
  85   return SCM_BOOL_F;
  86 }