lib: added 'slice' method to List

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/lib/standard/collection/list.nit b/lib/standard/collection/list.nit
index 40514fc..3dfac41 100644 (file)
--- a/lib/standard/collection/list.nit
+++ b/lib/standard/collection/list.nit
@@ -76,6 +76,18 @@ class List[E]
                return nb
        end
 
+       # Return a list of elements between 'from' and 'to'.
+       fun slice(from: Int, to: Int): List[E] do
+               assert from >= 0 and from < length
+               assert to >= 0 and to < length and from <= to
+               var list = new List[E]
+               while from <= to do
+                       list.add(self[from])
+                       from += 1
+               end
+               return list
+       end
+
 # Add elements
 
        # O(1)

diff --git a/tests/sav/test_list3.res b/tests/sav/test_list3.res
new file mode 100644 (file)
index 0000000..0c81794
--- /dev/null
+++ b/tests/sav/test_list3.res
@@ -0,0 +1,7 @@
+4
+5
+6
+1
+2
+3
+4

diff --git a/tests/test_list3.nit b/tests/test_list3.nit
new file mode 100644 (file)
index 0000000..48d002e
--- /dev/null
+++ b/tests/test_list3.nit
@@ -0,0 +1,23 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2009 Jean Privat <jean@pryen.org>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+var l = new List[Int].from([1, 2, 3, 4, 5, 6])
+
+var l1 = l.slice(3, 5)
+var l2 = l.slice(0, 3)
+
+for i in l1 do print i
+for i in l2 do print i