implement bigint rand op

Raku · Sep 22, 2012 · 8ae6f20 · 8ae6f20
1 parent c458a08
commit 8ae6f20
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diff --git a/src/QAST/Operations.nqp b/src/QAST/Operations.nqp
@@ -1283,6 +1283,7 @@ QAST::Operations.add_core_pirop_mapping('mod_i', 'mod', 'Iii', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('mod_I', 'nqp_bigint_mod', 'PPPP', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('expmod_I', 'nqp_bigint_exp_mod', 'PPPPP', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('isprime_I', 'nqp_bigint_is_prime', 'IPi', :inlinable(1));
+QAST::Operations.add_core_pirop_mapping('rand_I', 'nqp_bigint_rand', 'PPP', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('mod_n', 'mod', 'Nnn', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('pow_n', 'pow', 'Nnn', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('pow_I', 'nqp_bigint_pow', 'PPPPP', :inlinable(1));

diff --git a/src/ops/nqp_bigint.ops b/src/ops/nqp_bigint.ops
@@ -199,6 +199,19 @@ inline op nqp_bigint_is_prime(out INT, invar PMC, in INT) {
     }
 }
 
+/* generates a pseudo random number up to $2 of type $3 */
+inline op nqp_bigint_rand(out PMC, invar PMC, invar PMC) :base_core {
+    mp_int *a = get_bigint(interp, $2);
+    mp_int *b = NULL;
+
+    $1 = REPR($3)->allocate(interp, STABLE($3));
+    REPR($1)->initialize(interp, STABLE($1), OBJECT_BODY($1));
+
+    b = get_bigint(interp, $1);
+    mp_rand(b, USED(a) + 1);
+    mp_mod(b, a, b);
+}
+
 
 inline op nqp_bigint_neg(out PMC, in PMC, in PMC) :base_core {
     mp_int *a = get_bigint(interp, $2);