stdlib/strings: Added flatten service.
[nit.git] / lib / standard / string.nit
index f348b75..e47399b 100644 (file)
@@ -169,7 +169,8 @@ abstract class Text
        # As with substring, a `from` index < 0 will be replaced by 0
        fun substring_from(from: Int): SELFTYPE
        do
-               assert from < length
+               if from > self.length then return empty
+               if from < 0 then from = 0
                return substring(from, length - from)
        end
 
@@ -452,6 +453,9 @@ abstract class Text
                return self.chars < o.chars
        end
 
+       # Flat representation of self
+       fun flatten: FlatText is abstract
+
 end
 
 # All kinds of array-based text representations.
@@ -472,6 +476,8 @@ abstract class FlatText
                        i += 1
                end
        end
+
+       redef fun flatten do return self
 end
 
 # Abstract class for the SequenceRead compatible
@@ -583,11 +589,21 @@ abstract class BufferCharView
 
 end
 
+abstract class String
+       super Text
+
+       redef type SELFTYPE: String
+
+       redef fun to_s do return self
+
+end
+
 # Immutable strings of characters.
-class String
+class FlatString
        super FlatText
+       super String
 
-       redef type SELFTYPE: String
+       redef type SELFTYPE: FlatString
        redef type SELFVIEW: FlatStringCharView
 
        # Index in _items of the start of the string
@@ -622,16 +638,16 @@ class String
 
                var realFrom = index_from + from
 
-               if (realFrom + count) > index_to then return new String.with_infos(items, index_to - realFrom + 1, realFrom, index_to)
+               if (realFrom + count) > index_to then return new FlatString.with_infos(items, index_to - realFrom + 1, realFrom, index_to)
 
-               if count == 0 then return ""
+               if count == 0 then return empty
 
                var to = realFrom + count - 1
 
-               return new String.with_infos(items, to - realFrom + 1, realFrom, to)
+               return new FlatString.with_infos(items, to - realFrom + 1, realFrom, to)
        end
 
-       redef fun empty do return "".as(String)
+       redef fun empty do return "".as(FlatString)
 
        redef fun to_upper
        do
@@ -709,7 +725,7 @@ class String
 
        redef fun ==(other)
        do
-               if not other isa String then return super
+               if not other isa FlatString then return super
 
                if self.object_id == other.object_id then return true
 
@@ -739,7 +755,7 @@ class String
        #     assert ("aa" < "b")      ==  true
        redef fun <(other)
        do
-               if not other isa String then return super
+               if not other isa FlatString then return super
 
                if self.object_id == other.object_id then return false
 
@@ -786,7 +802,7 @@ class String
                var target_string = calloc_string(my_length + its_length + 1)
 
                self.items.copy_to(target_string, my_length, index_from, 0)
-               if s isa String then
+               if s isa FlatString then
                        s.items.copy_to(target_string, its_length, s.index_from, my_length)
                else if s isa FlatBuffer then
                        s.items.copy_to(target_string, its_length, 0, my_length)
@@ -830,8 +846,6 @@ class String
                return target_string.to_s_with_length(final_length)
        end
 
-       redef fun to_s do return self
-
        redef fun hash
        do
                # djb2 hash algorythm
@@ -855,13 +869,13 @@ end
 private class FlatStringReverseIterator
        super IndexedIterator[Char]
 
-       var target: String
+       var target: FlatString
 
        var target_items: NativeString
 
        var curr_pos: Int
 
-       init with_pos(tgt: String, pos: Int)
+       init with_pos(tgt: FlatString, pos: Int)
        do
                target = tgt
                target_items = tgt.items
@@ -881,13 +895,13 @@ end
 private class FlatStringIterator
        super IndexedIterator[Char]
 
-       var target: String
+       var target: FlatString
 
        var target_items: NativeString
 
        var curr_pos: Int
 
-       init with_pos(tgt: String, pos: Int)
+       init with_pos(tgt: FlatString, pos: Int)
        do
                target = tgt
                target_items = tgt.items
@@ -907,7 +921,7 @@ end
 private class FlatStringCharView
        super StringCharView
 
-       redef type SELFTYPE: String
+       redef type SELFTYPE: FlatString
 
        redef fun [](index)
        do
@@ -946,8 +960,8 @@ abstract class Buffer
        # Enlarges the subsequent array containing the chars of self
        fun enlarge(cap: Int) is abstract
 
-       # Adds the content of string `s` at the end of self
-       fun append(s: String) is abstract
+       # Adds the content of text `s` at the end of self
+       fun append(s: Text) is abstract
 
 end
 
@@ -1014,12 +1028,22 @@ class FlatBuffer
                with_capacity(5)
        end
 
-       init from(s: String)
+       init from(s: Text)
        do
                capacity = s.length + 1
                length = s.length
                items = calloc_string(capacity)
-               s.items.copy_to(items, length, s.index_from, 0)
+               if s isa FlatString then
+                       s.items.copy_to(items, length, s.index_from, 0)
+               else if s isa FlatBuffer then
+                       s.items.copy_to(items, length, 0, 0)
+               else
+                       var curr_pos = 0
+                       for i in s.chars do
+                               items[curr_pos] = i
+                               curr_pos += 1
+                       end
+               end
        end
 
        # Create a new empty string with a given capacity.
@@ -1036,7 +1060,17 @@ class FlatBuffer
        do
                var sl = s.length
                if capacity < length + sl then enlarge(length + sl)
-               s.items.copy_to(items, sl, s.index_from, length)
+               if s isa FlatString then
+                       s.items.copy_to(items, sl, s.index_from, length)
+               else if s isa FlatBuffer then
+                       s.items.copy_to(items, sl, 0, length)
+               else
+                       var curr_pos = self.length
+                       for i in s.chars do
+                               items[curr_pos] = i
+                               curr_pos += 1
+                       end
+               end
                length += sl
        end
 
@@ -1495,18 +1529,18 @@ class NativeString
                return to_s_with_length(cstring_length)
        end
 
-       fun to_s_with_length(length: Int): String
+       fun to_s_with_length(length: Int): FlatString
        do
                assert length >= 0
-               return new String.with_infos(self, length, 0, length - 1)
+               return new FlatString.with_infos(self, length, 0, length - 1)
        end
 
-       fun to_s_with_copy: String
+       fun to_s_with_copy: FlatString
        do
                var length = cstring_length
                var new_self = calloc_string(length + 1)
                copy_to(new_self, length, 0, 0)
-               return new String.with_infos(new_self, length, 0, length - 1)
+               return new FlatString.with_infos(new_self, length, 0, length - 1)
        end
 
 end