mrbgems/mruby-array-ext/src/array.c

   1 #include "mruby.h"
   2 #include "mruby/value.h"
   3 #include "mruby/array.h"
   4
   5 /*
   6  *  call-seq:
   7  *     Array.try_convert(obj) -> array or nil
   8  *
   9  *  Try to convert <i>obj</i> into an array, using +to_ary+ method.
  10  *  Returns converted array or +nil+ if <i>obj</i> cannot be converted
  11  *  for any reason. This method can be used to check if an argument is an
  12  *  array.
  13  *
  14  *     Array.try_convert([1])   #=> [1]
  15  *     Array.try_convert("1")   #=> nil
  16  *
  17  *     if tmp = Array.try_convert(arg)
  18  *       # the argument is an array
  19  *     elsif tmp = String.try_convert(arg)
  20  *       # the argument is a string
  21  *     end
  22  *
  23  */
  24
  25 static mrb_value
  26 mrb_ary_s_try_convert(mrb_state *mrb, mrb_value self)
  27 {
  28   mrb_value ary;
  29
  30   mrb_get_args(mrb, "o", &ary);
  31   return mrb_check_array_type(mrb, ary);
  32 }
  33
  34 /*
  35  *  call-seq:
  36  *     ary.assoc(obj)   -> new_ary  or  nil
  37  *
  38  *  Searches through an array whose elements are also arrays
  39  *  comparing _obj_ with the first element of each contained array
  40  *  using obj.==.
  41  *  Returns the first contained array that matches (that
  42  *  is, the first associated array),
  43  *  or +nil+ if no match is found.
  44  *  See also <code>Array#rassoc</code>.
  45  *
  46  *     s1 = [ "colors", "red", "blue", "green" ]
  47  *     s2 = [ "letters", "a", "b", "c" ]
  48  *     s3 = "foo"
  49  *     a  = [ s1, s2, s3 ]
  50  *     a.assoc("letters")  #=> [ "letters", "a", "b", "c" ]
  51  *     a.assoc("foo")      #=> nil
  52  */
  53
  54 static mrb_value
  55 mrb_ary_assoc(mrb_state *mrb, mrb_value ary)
  56 {
  57   mrb_int i;
  58   mrb_value v, k;
  59
  60   mrb_get_args(mrb, "o", &k);
  61
  62   for (i = 0; i < RARRAY_LEN(ary); ++i) {
  63     v = mrb_check_array_type(mrb, RARRAY_PTR(ary)[i]);
  64     if (!mrb_nil_p(v) && RARRAY_LEN(v) > 0 &&
  65         mrb_equal(mrb, RARRAY_PTR(v)[0], k))
  66       return v;
  67   }
  68   return mrb_nil_value();
  69 }
  70
  71 /*
  72  *  call-seq:
  73  *     ary.rassoc(obj) -> new_ary or nil
  74  *
  75  *  Searches through the array whose elements are also arrays. Compares
  76  *  _obj_ with the second element of each contained array using
  77  *  <code>==</code>. Returns the first contained array that matches. See
  78  *  also <code>Array#assoc</code>.
  79  *
  80  *     a = [ [ 1, "one"], [2, "two"], [3, "three"], ["ii", "two"] ]
  81  *     a.rassoc("two")    #=> [2, "two"]
  82  *     a.rassoc("four")   #=> nil
  83  */
  84
  85 static mrb_value
  86 mrb_ary_rassoc(mrb_state *mrb, mrb_value ary)
  87 {
  88   mrb_int i;
  89   mrb_value v, value;
  90
  91   mrb_get_args(mrb, "o", &value);
  92
  93   for (i = 0; i < RARRAY_LEN(ary); ++i) {
  94     v = RARRAY_PTR(ary)[i];
  95     if (mrb_type(v) == MRB_TT_ARRAY &&
  96         RARRAY_LEN(v) > 1 &&
  97         mrb_equal(mrb, RARRAY_PTR(v)[1], value))
  98       return v;
  99   }
 100   return mrb_nil_value();
 101 }
 102
 103 /*
 104  *  call-seq:
 105  *     ary.at(index)   ->   obj  or nil
 106  *
 107  *  Returns the element at _index_. A
 108  *  negative index counts from the end of +self+.  Returns +nil+
 109  *  if the index is out of range. See also <code>Array#[]</code>.
 110  *
 111  *     a = [ "a", "b", "c", "d", "e" ]
 112  *     a.at(0)     #=> "a"
 113  *     a.at(-1)    #=> "e"
 114  */
 115
 116 static mrb_value
 117 mrb_ary_at(mrb_state *mrb, mrb_value ary)
 118 {
 119   mrb_int pos;
 120   mrb_get_args(mrb, "i", &pos);
 121
 122   return mrb_ary_entry(ary, pos);
 123 }
 124
 125 void
 126 mrb_mruby_array_ext_gem_init(mrb_state* mrb)
 127 {
 128   struct RClass * a = mrb->array_class;
 129
 130   mrb_define_class_method(mrb, a, "try_convert", mrb_ary_s_try_convert, MRB_ARGS_REQ(1));
 131
 132   mrb_define_method(mrb, a, "assoc",  mrb_ary_assoc,  MRB_ARGS_REQ(1));
 133   mrb_define_method(mrb, a, "at",     mrb_ary_at,     MRB_ARGS_REQ(1));
 134   mrb_define_method(mrb, a, "rassoc", mrb_ary_rassoc, MRB_ARGS_REQ(1));
 135 }
 136
 137 void
 138 mrb_mruby_array_ext_gem_final(mrb_state* mrb)
 139 {
 140 }