lily/module-scheme.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2005--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "ly-module.hh"
  21
  22 #include "warn.hh"
  23 #include "main.hh"
  24 #include "std-string.hh"
  25
  26
  27 /*
  28   If a variable is changed in SRC, then DEST doesn't see the
  29   definitions.
  30 */
  31
  32 static SCM
  33 module_define_closure_func (void *closure,
  34                             SCM key,
  35                             SCM val,
  36                             SCM /* result */)
  37 {
  38   SCM module = (SCM) closure;
  39   if (scm_variable_bound_p (val) == SCM_BOOL_T)
  40     scm_module_define (module, key, scm_variable_ref (val));
  41   return SCM_EOL;
  42 }
  43
  44 LY_DEFINE (ly_module_copy, "ly:module-copy",
  45            2, 0, 0, (SCM dest, SCM src),
  46            "Copy all bindings from module @var{src} into @var{dest}.")
  47 {
  48 #define FUNC_NAME __FUNCTION__
  49   SCM_VALIDATE_MODULE (1, src);
  50   scm_internal_hash_fold ((scm_t_hash_fold_fn) &module_define_closure_func,
  51                           (void *) dest,
  52                           SCM_EOL, SCM_MODULE_OBARRAY (src));
  53   return SCM_UNSPECIFIED;
  54 }
  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 }