range: add some nitunit and examples

[nit.git] / lib / standard / collection / range.nit

diff --git a/lib/standard/collection/range.nit b/lib/standard/collection/range.nit
index eb3aef3..d187cfb 100644 (file)
--- a/lib/standard/collection/range.nit
+++ b/lib/standard/collection/range.nit
@@ -19,18 +19,25 @@ import abstract_collection
 class Range[E: Discrete]
        super Collection[E]
 
-       redef readable var _first: E
+       redef var first: E
 
        # Get the last element.
-       readable var _last: E
+       var last: E
 
        # Get the element after the last one.
-       readable var _after: E
+       var after: E
 
-       redef fun has(item) do return item >= _first and item <= _last
+       #     assert [1..10].has(5)
+       #     assert [1..10].has(10)
+       #     assert not [1..10[.has(10)
+       redef fun has(item) do return item >= first and item <= last
 
-       redef fun has_only(item) do return _first == item and item == _last or is_empty
+       #     assert [1..1].has_only(1)
+       #     assert not [1..10].has_only(1)
+       redef fun has_only(item) do return first == item and item == last or is_empty
 
+       #     assert [1..10].count(1)   == 1
+       #     assert [1..10].count(0)   == 0
        redef fun count(item)
        do
                if has(item) then
@@ -44,7 +51,7 @@ class Range[E: Discrete]
 
        redef fun length
        do
-               var nb = _first.distance(_after)
+               var nb = first.distance(after)
                if nb > 0 then
                        return nb
                else
@@ -52,41 +59,52 @@ class Range[E: Discrete]
                end
        end
 
-       redef fun is_empty do return _first >= _after
+       #     assert not [1..10[.is_empty
+       #     assert not [1..1].is_empty
+       #     assert [1..-10].is_empty
+       redef fun is_empty do return first >= after
 
        # Create a range [`from`, `to`].
-       # The syntax `[from..to[` is equivalent.
-       init(from: E, to: E)
-       do
-               _first = from
-               _last = to
-               _after = to.succ
+       # The syntax `[from..to]` is equivalent.
+       #
+       #     var a = [10..15]
+       #     var b = new Range[Int] (10,15)
+       #     assert a == b
+       #     assert a.to_a == [10, 11, 12, 13, 14, 15]
+       init(from: E, to: E) is old_style_init do
+               first = from
+               last = to
+               after = to.successor(1)
        end
 
        # Create a range [`from`, `to`[.
        # The syntax `[from..to[` is equivalent.
+       #
+       #     var a = [10..15[
+       #     var b = new Range[Int].without_last(10,15)
+       #     assert a == b
+       #     assert a.to_a == [10, 11, 12, 13, 14]
        init without_last(from: E, to: E)
        do
-               _first = from
-               _last = to.prec
-               _after = to
+               first = from
+               last = to.predecessor(1)
+               after = to
        end
 end
 
-class IteratorRange[E: Discrete]
+private class IteratorRange[E: Discrete]
        # Iterator on ranges.
        super Iterator[E]
-       var _range: Range[E]
-       redef readable var _item: E
+       var range: Range[E]
+       redef var item is noinit
 
        redef fun is_ok do return _item < _range.after
        
-       redef fun next do _item = _item.succ
+       redef fun next do _item = _item.successor(1)
        
-       init(r: Range[E])
+       init
        do
-               _range = r
-               _item = r.first
+               _item = _range.first
        end
 end