bugfix: floating point precision; added strutils.formatFloat

rod/rodutils.nim

@@ -0,0 +1,27 @@
+#
+#
+#           The Nimrod Compiler
+#        (c) Copyright 2011 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Utilities for the compiler. Aim is to reduce the coupling between 
+## the compiler and the evolving stdlib.
+
+proc c_sprintf(buf, frmt: cstring) {.importc: "sprintf", nodecl, varargs.}
+
+proc ToStrMaxPrecision*(f: BiggestFloat): string = 
+  if f != f:
+    result = "NAN"
+  elif f == 0.0:
+    result = "0.0"
+  elif f == 0.5 * f:
+    if f > 0.0: result = "INF"
+    else: result = "-INF"
+  else:
+    var buf: array [0..80, char]    
+    c_sprintf(buf, "%#.16e", f) 
+    result = $buf
+