lib/core: Added escaping method to Bytes for use in compiler

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>

diff --git a/lib/core/bytes.nit b/lib/core/bytes.nit
index 1cac7ac..a1dbfbe 100644 (file)
--- a/lib/core/bytes.nit
+++ b/lib/core/bytes.nit
@@ -318,6 +318,57 @@ redef class Text
                end
                return new FlatString.with_infos(outns, ln * 2, 0, ln * 2 - 1)
        end
+
+       # Return a `Bytes` instance where Nit escape sequences are transformed.
+       #
+       #     assert "B\\n\\x41\\u0103D3".unescape_to_bytes.hexdigest == "420A41F0908F93"
+       fun unescape_to_bytes: Bytes do
+               var res = new Bytes.with_capacity(self.bytelen)
+               var was_slash = false
+               var i = 0
+               while i < length do
+                       var c = chars[i]
+                       if not was_slash then
+                               if c == '\\' then
+                                       was_slash = true
+                               else
+                                       res.add_char(c)
+                               end
+                               i += 1
+                               continue
+                       end
+                       was_slash = false
+                       if c == 'n' then
+                               res.add_char('\n')
+                       else if c == 'r' then
+                               res.add_char('\r')
+                       else if c == 't' then
+                               res.add_char('\t')
+                       else if c == '0' then
+                               res.add_char('\0')
+                       else if c == 'x' or c == 'X' then
+                               var hx = substring(i + 1, 2)
+                               if hx.is_hex then
+                                       res.add(hx.to_hex.to_b)
+                               else
+                                       res.add_char(c)
+                               end
+                               i += 2
+                       else if c == 'u' or c == 'U' then
+                               var hx = substring(i + 1, 6)
+                               if hx.is_hex then
+                                       res.add_char(hx.to_hex.code_point)
+                               else
+                                       res.add_char(c)
+                               end
+                               i += 6
+                       else
+                               res.add_char(c)
+                       end
+                       i += 1
+               end
+               return res
+       end
 end
 
 redef class FlatText