parser: add `is_loose`, `prev_looses` and `next_looses`

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

diff --git a/lib/standard/collection/range.nit b/lib/standard/collection/range.nit
index e72771e..da68294 100644 (file)
--- a/lib/standard/collection/range.nit
+++ b/lib/standard/collection/range.nit
@@ -27,10 +27,17 @@ class Range[E: Discrete]
        # Get the element after the last one.
        var after: E
 
+       #     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
 
+       #     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
@@ -42,8 +49,13 @@ class Range[E: Discrete]
 
        redef fun iterator do return new IteratorRange[E](self)
 
+       #     assert [1..10].length             == 10
+       #     assert [1..10[.length             == 9
+       #     assert [1..1].length              == 1
+       #     assert [1..-10].length    == 0
        redef fun length
        do
+               if is_empty then return 0
                var nb = first.distance(after)
                if nb > 0 then
                        return nb
@@ -52,12 +64,19 @@ class Range[E: Discrete]
                end
        end
 
+       #     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
+       # 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)
@@ -65,41 +84,67 @@ class Range[E: Discrete]
 
        # 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.predecessor(1)
                after = to
        end
+
+       # Two ranges are equals if they have the same first and last elements.
+       #
+       #     var a = new Range[Int](10, 15)
+       #     var b = new Range[Int].without_last(10, 15)
+       #     assert a == [10..15]
+       #     assert a == [10..16[
+       #     assert not a == [10..15[
+       #     assert b == [10..15[
+       #     assert b == [10..14]
+       #     assert not b == [10..15]
+       redef fun ==(o) do
+               return o isa Range[E] and self.first == o.first and self.last == o.last
+       end
+
+       #     var a = new Range[Int](10, 15)
+       #     assert a.hash == 455
+       #     var b = new Range[Int].without_last(10, 15)
+       #     assert b.hash == 432
+       redef fun hash do
+               # 11 and 23 are magic numbers empirically determined to be not so bad.
+               return first.hash * 11 + last.hash * 23
+       end
 end
 
 private class IteratorRange[E: Discrete]
        # Iterator on ranges.
        super Iterator[E]
-       var _range: Range[E]
-       var _item: E
-       redef fun item do return _item
+       var range: Range[E]
+       redef var item is noinit
 
        redef fun is_ok do return _item < _range.after
        
        redef fun next do _item = _item.successor(1)
        
-       init(r: Range[E])
+       init
        do
-               _range = r
-               _item = r.first
+               _item = _range.first
        end
 end
 
 redef class Int
        # Returns the range from 0 to `self-1`, is used to do:
        #
-       #    var s = new Array[String]
-       #    for i in 3.times do s.add "cool"
-       #    assert s.join(" ") == "cool cool cool"
+       #     var s = new Array[String]
+       #     for i in 3.times do s.add "cool"
+       #     assert s.join(" ") == "cool cool cool"
        #
-       #    s.clear
-       #    for i in 10.times do s.add(i.to_s)
-       #    assert s.to_s == "0123456789"
+       #     s.clear
+       #     for i in 10.times do s.add(i.to_s)
+       #     assert s.to_s == "0123456789"
        fun times: Range[Int] do return [0 .. self[
 end