1 /*
2 ** hash.c - Hash class
3 **
4 ** See Copyright Notice in mruby.h
5 */
6
7 #include <mruby.h>
8 #include <mruby/array.h>
9 #include <mruby/hash.h>
10
11 /*
12 * call-seq:
13 * hsh.values_at(key, ...) -> array
14 *
15 * Return an array containing the values associated with the given keys.
16 * Also see <code>Hash.select</code>.
17 *
18 * h = { "cat" => "feline", "dog" => "canine", "cow" => "bovine" }
19 * h.values_at("cow", "cat") #=> ["bovine", "feline"]
20 */
21
22 static mrb_value
hash_values_at(mrb_state * mrb,mrb_value hash)23 hash_values_at(mrb_state *mrb, mrb_value hash)
24 {
25 mrb_value *argv, result;
26 mrb_int argc, i;
27 int ai;
28
29 mrb_get_args(mrb, "*", &argv, &argc);
30 result = mrb_ary_new_capa(mrb, argc);
31 ai = mrb_gc_arena_save(mrb);
32 for (i = 0; i < argc; i++) {
33 mrb_ary_push(mrb, result, mrb_hash_get(mrb, hash, argv[i]));
34 mrb_gc_arena_restore(mrb, ai);
35 }
36 return result;
37 }
38
39 /*
40 * call-seq:
41 * hsh.slice(*keys) -> a_hash
42 *
43 * Returns a hash containing only the given keys and their values.
44 *
45 * h = { a: 100, b: 200, c: 300 }
46 * h.slice(:a) #=> {:a=>100}
47 * h.slice(:b, :c, :d) #=> {:b=>200, :c=>300}
48 */
49 static mrb_value
hash_slice(mrb_state * mrb,mrb_value hash)50 hash_slice(mrb_state *mrb, mrb_value hash)
51 {
52 mrb_value *argv, result;
53 mrb_int argc, i;
54
55 mrb_get_args(mrb, "*", &argv, &argc);
56 if (argc == 0) {
57 return mrb_hash_new_capa(mrb, argc);
58 }
59 result = mrb_hash_new_capa(mrb, argc);
60 for (i = 0; i < argc; i++) {
61 mrb_value key = argv[i];
62 mrb_value val;
63
64 val = mrb_hash_fetch(mrb, hash, key, mrb_undef_value());
65 if (!mrb_undef_p(val)) {
66 mrb_hash_set(mrb, result, key, val);
67 }
68 }
69 return result;
70 }
71
72 void
mrb_mruby_hash_ext_gem_init(mrb_state * mrb)73 mrb_mruby_hash_ext_gem_init(mrb_state *mrb)
74 {
75 struct RClass *h;
76
77 h = mrb->hash_class;
78 mrb_define_method(mrb, h, "values_at", hash_values_at, MRB_ARGS_ANY());
79 mrb_define_method(mrb, h, "slice", hash_slice, MRB_ARGS_ANY());
80 }
81
82 void
mrb_mruby_hash_ext_gem_final(mrb_state * mrb)83 mrb_mruby_hash_ext_gem_final(mrb_state *mrb)
84 {
85 }
86