lib/core: extend is_numeric to support negatives (!) and e notation

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/core/text/abstract_text.nit b/lib/core/text/abstract_text.nit
index 8b9b68b..e201e0c 100644 (file)
--- a/lib/core/text/abstract_text.nit
+++ b/lib/core/text/abstract_text.nit
@@ -309,16 +309,22 @@ abstract class Text
        #
        #     assert "123".is_numeric  == true
        #     assert "1.2".is_numeric  == true
+       #     assert "-1.2".is_numeric == true
        #     assert "1,2".is_numeric  == true
+       #     assert "-1.23e-2".is_numeric == true
        #     assert "1..2".is_numeric == false
        fun is_numeric: Bool
        do
                var has_point_or_comma = false
+               var e_index = -1
                for i in [0..length[ do
                        var c = chars[i]
                        if not c.is_numeric then
                                if (c == '.' or c == ',') and not has_point_or_comma then
                                        has_point_or_comma = true
+                               else if c == 'e' and e_index == -1 and i > 0 and i < length - 1 and chars[i-1] != '-' then
+                                       e_index = i
+                               else if c == '-' and i == e_index + 1 and i < length - 1 then
                                else
                                        return false
                                end