conversion: added from_* methods

silly.c

@@ -96,3 +96,23 @@ silly make_silly(short sign, int before, int after) {
   s.after = after;
   return s;
 }
+
+silly silly_from_float(float x) {
+  silly s;
+  double _;
+  s.sign = signbit(x);
+  x = fabs(x);
+  s.before = trunc(x);
+  s.after = modf(x, &_);
+  return s;
+}
+
+silly silly_from_double(double x) {
+  silly s;
+  double _;
+  s.sign = signbit(x);
+  x = fabs(x);
+  s.before = trunc(x);
+  s.after = modf(x, &_);
+  return s;
+}

silly.h

@@ -1,3 +1,4 @@
+#include <math.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -15,8 +16,8 @@ silly silly_add(silly, silly);
 silly silly_sub(silly, silly);
 silly silly_mul(silly, silly);
 
-//silly silly_from_32(float);
+silly silly_from_float(float);
-//silly silly_from_64(double);
+silly silly_from_double(double);
 double silly_to_double(silly);
 
 char* silly_to_string(silly);

tests/test.c

@@ -100,6 +100,17 @@ TEST silly_conversion() {
   x.before = 1;
   x.after = (int)(((double)0xffffffff)/10);
   ASSERT(-1.1 - silly_to_double(x) <= 0.01);
+
+  x = silly_from_float(0.0);
+  ASSERT_EQ_FMT(0.0, silly_to_double(x), "%f");
+  x = silly_from_float(-1.1);
+  ASSERT(-1.1 - silly_to_double(x) <= 0.01);
+
+  x = silly_from_double((double) 0.0);
+  ASSERT_EQ_FMT(0.0, silly_to_double(x), "%f");
+  x = silly_from_double((double) -1.1);
+  ASSERT(-1.1 - silly_to_double(x) <= 0.01);
+
   PASS();
 }