Merge remote-tracking branch 'github/pr/292/head'

[nit.git] / lib / standard / math.nit

diff --git a/lib/standard/math.nit b/lib/standard/math.nit
index eaaf2e6..340222a 100644 (file)
--- a/lib/standard/math.nit
+++ b/lib/standard/math.nit
@@ -16,7 +16,12 @@ module math
 import kernel
 import collection
 
+in "C header" `{
+#include <math.h>
+`}
+
 redef class Int
+       # Returns a random `Int` in `[0 .. self[`.
        fun rand: Int is extern "kernel_Int_Int_rand_0"
        fun bin_and(i: Int): Int is extern "kernel_Int_Int_binand_0"
        fun bin_or(i: Int): Int is extern "kernel_Int_Int_binor_0"
@@ -34,20 +39,23 @@ redef class Float
        fun acos: Float is extern "kernel_Float_Float_acos_0"
        fun asin: Float is extern "kernel_Float_Float_asin_0"
        fun atan: Float is extern "kernel_Float_Float_atan_0"
+       fun abs: Float `{ return abs(recv); `}
 
        fun pow(e: Float): Float is extern "kernel_Float_Float_pow_1"
        fun log: Float is extern "kernel_Float_Float_log_0"
        fun exp: Float is extern "kernel_Float_Float_exp_0"
        
+       # Returns a random `Float` in `[0.0 .. self[`.
        fun rand: Float is extern "kernel_Float_Float_rand_0"
        fun hypot_with( b : Float ) : Float is extern "hypotf"
 end
 
 redef class Collection[ E ]
-       # Return a random element in the collection
-       fun rand : nullable E
+       # Return a random element form the collection
+       # There must be at least one element in the collection
+       fun rand: E
        do
-               if is_empty then return null
+               if is_empty then abort
                var rand_index = length.rand
 
                for e in self do