lily/include/scm-hash.hh

   1 /*
   2   scm-hash.hh -- declare Scheme hasher.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #ifndef SCM_HASH_HH
  11 #define SCM_HASH_HH
  12
  13
  14 #include "lily-guile.hh"
  15 #include "smobs.hh"
  16
  17
  18 /**
  19    auto resizing hash table.
  20
  21    1. ALWAYS USE THIS AS VIA A POINTER, i.e.
  22
  23    class Foo {
  24     Scheme_hash_table * tab;
  25    };
  26
  27    and NOT
  28
  29    class Foo {
  30     Scheme_hash_table tab;
  31    }
  32
  33
  34    2. UPON DESTRUCTION, DO
  35
  36    scm_gc_unprotect_object (tab->self_scm_);
  37
  38  */
  39
  40 class Scheme_hash_table
  41 {
  42 public:
  43   bool try_retrieve (SCM key, SCM *val);
  44   bool elem_b (SCM key) const;
  45
  46   /**
  47      WARNING: putting something in assumes responsibility for cleaning
  48      up.  */
  49   void set (SCM k, SCM v);
  50   SCM get (SCM k) const;
  51   void remove (SCM k);
  52   Scheme_hash_table ();
  53   void operator = (Scheme_hash_table const &);
  54   Scheme_hash_table (Scheme_hash_table const &);
  55
  56   SCM to_alist () const;
  57 private:
  58   SCM hash_tab_;
  59   unsigned elt_count_;
  60
  61   DECLARE_SMOBS (Scheme_hash_table,foo);
  62 };
  63
  64
  65 #endif /* SCM_HASH_HH */
  66