+
+ # Escape additionnal characters
+ # The result might no be legal in C but be used in other languages
+ #
+ # assert "ab|\{\}".escape_more_to_c("|\{\}") == "ab\\|\\\{\\\}"
+ fun escape_more_to_c(chars: String): String
+ do
+ var b = new FlatBuffer
+ for c in escape_to_c do
+ if chars.chars.has(c) then
+ b.add('\\')
+ end
+ b.add(c)
+ end
+ return b.to_s
+ end
+
+ # Escape to c plus braces
+ #
+ # assert "\n\"'\\\{\}".escape_to_nit == "\\n\\\"\\'\\\\\\\{\\\}"
+ fun escape_to_nit: String do return escape_more_to_c("\{\}")
+
+ # Return a string where Nit escape sequences are transformed.
+ #
+ # Example:
+ # var s = "\\n"
+ # assert s.length == 2
+ # var u = s.unescape_nit
+ # assert u.length == 1
+ # assert u[0].ascii == 10 # (the ASCII value of the "new line" character)
+ fun unescape_nit: String
+ do
+ var res = new FlatBuffer.with_capacity(self.length)
+ var was_slash = false
+ for c in self do
+ if not was_slash then
+ if c == '\\' then
+ was_slash = true
+ else
+ res.add(c)
+ end
+ continue
+ end
+ was_slash = false
+ if c == 'n' then
+ res.add('\n')
+ else if c == 'r' then
+ res.add('\r')
+ else if c == 't' then
+ res.add('\t')
+ else if c == '0' then
+ res.add('\0')
+ else
+ res.add(c)
+ end
+ end
+ return res.to_s
+ end
+
+end
+
+# Common subclass for String and Buffer
+abstract class AbstractString
+ super Text
+
+ private var items: NativeString
+
+ redef var length: Int
+
+ init do end
+
+ redef fun output
+ do
+ var i = 0
+ while i < length do
+ items[i].output
+ i += 1
+ end
+ end
+end
+
+# Abstract class for the SequenceRead compatible
+# views on String and Buffer objects
+abstract class StringCharView
+ super SequenceRead[Char]
+
+ type SELFTYPE: Text
+
+ private var target: SELFTYPE
+
+ private init(tgt: SELFTYPE)
+ do
+ target = tgt
+ end
+
+ redef fun is_empty do return target.is_empty
+
+ redef fun length do return target.length
+
+ redef fun iterator: IndexedIterator[Char] do return self.iterator_from(0)
+
+ # Gets a new Iterator starting at position `pos`
+ #
+ # Ex :
+ # var iter = "abcd".iterator_from(2)
+ # while iter.is_ok do
+ # printn iter.item
+ # iter.next
+ # end
+ #
+ # Outputs : cd
+ fun iterator_from(pos: Int): IndexedIterator[Char] is abstract
+
+ # Gets an iterator starting at the end and going backwards
+ #
+ # Ex :
+ # var reviter = "now step live...".reverse_iterator
+ # while reviter.is_ok do
+ # printn reviter.item
+ # reviter.next
+ # end
+ #
+ # Outputs : ...evil pets won
+ fun reverse_iterator: IndexedIterator[Char] do return self.reverse_iterator_from(self.length - 1)
+
+ # Gets an iterator on the chars of self starting from `pos`
+ #
+ # Ex :
+ # var iter = "abcd".reverse_iterator_from(1)
+ # while iter.is_ok do
+ # printn iter.item
+ # iter.next
+ # end
+ #
+ # Outputs : ba
+ fun reverse_iterator_from(pos: Int): IndexedIterator[Char] is abstract
+
+ redef fun has(c: Char): Bool
+ do
+ for i in self do
+ if i == c then return true
+ end
+ return false
+ end
+
+end
+
+# View on Buffer objects, extends Sequence
+# for mutation operations
+abstract class BufferCharView
+ super StringCharView
+ super Sequence[Char]
+
+ redef type SELFTYPE: Buffer
+