lib/text: `Text::format` harder to break and using `%%` as escape

[nit.git] / lib / core / text / abstract_text.nit

diff --git a/lib/core/text/abstract_text.nit b/lib/core/text/abstract_text.nit
index 8b9b68b..0d2848c 100644 (file)
--- a/lib/core/text/abstract_text.nit
+++ b/lib/core/text/abstract_text.nit
@@ -305,26 +305,32 @@ abstract class Text
                end
        end
 
-       # Returns `true` if the string contains only Numeric values (and one "," or one "." character)
+       # Is this string in a valid numeric format compatible with `to_f`?
        #
        #     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
+       #     assert "".is_numeric     == false
        fun is_numeric: Bool
        do
-               var has_point_or_comma = false
+               var has_point = 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
+                               if c == '.' and not has_point then
+                                       has_point = 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
                        end
                end
-               return true
+               return not is_empty
        end
 
        # Returns `true` if the string contains only Hex chars
@@ -958,36 +964,46 @@ abstract class Text
                return hash_cache.as(not null)
        end
 
-       # Gives the formatted string back as a Nit string with `args` in place
+       # Format `self` by replacing each `%n` with the `n`th item of `args`
+       #
+       # The character `%` followed by something other than a number are left as is.
+       # To represent a `%` followed by a number, double the `%`, as in `%%7`.
        #
-       #     assert "This %1 is a %2.".format("String", "formatted String") == "This String is a formatted String."
-       #     assert "\\%1 This string".format("String") == "\\%1 This string"
+       #     assert "This %0 is a %1.".format("String", "formatted String") == "This String is a formatted String."
+       #     assert "Do not escape % nor %%1".format("unused") == "Do not escape % nor %1"
        fun format(args: Object...): String do
                var s = new Array[Text]
                var curr_st = 0
                var i = 0
                while i < length do
-                       # Skip escaped characters
-                       if self[i] == '\\' then
-                               i += 1
-                       # In case of format
-                       else if self[i] == '%' then
+                       if self[i] == '%' then
                                var fmt_st = i
                                i += 1
                                var ciph_st = i
                                while i < length and self[i].is_numeric do
                                        i += 1
                                end
-                               i -= 1
-                               var fmt_end = i
-                               var ciph_len = fmt_end - ciph_st + 1
 
-                               var arg_index = substring(ciph_st, ciph_len).to_i - 1
+                               var ciph_len = i - ciph_st
+                               if ciph_len == 0 then
+                                       # What follows '%' is not a number.
+                                       s.push substring(curr_st, i - curr_st)
+                                       if i < length and self[i] == '%' then
+                                               # Skip the next `%`
+                                               i += 1
+                                       end
+                                       curr_st = i
+                                       continue
+                               end
+
+                               var arg_index = substring(ciph_st, ciph_len).to_i
                                if arg_index >= args.length then continue
 
                                s.push substring(curr_st, fmt_st - curr_st)
                                s.push args[arg_index].to_s
-                               curr_st = i + 1
+
+                               curr_st = i
+                               i -= 1
                        end
                        i += 1
                end
@@ -1548,7 +1564,7 @@ end
 redef class Int
 
        # Wrapper of strerror C function
-       private fun strerror_ext: NativeString `{ return strerror(self); `}
+       private fun strerror_ext: NativeString `{ return strerror((int)self); `}
 
        # Returns a string describing error number
        fun strerror: String do return strerror_ext.to_s