# assert [1..1[.is_empty == true
fun is_empty: Bool do return length == 0
+ # Alias for `not is_empty`.
+ #
+ # Some people prefer to have conditions grammatically easier to read.
+ #
+ # assert [1,2,3].not_empty == true
+ # assert [1..1[.not_empty == false
+ fun not_empty: Bool do return not self.is_empty
+
# Number of items in the collection.
#
# assert [10,20,30].length == 3
end
+redef class MapRead[K,V]
+ # Return an array of all values sorted with their keys using `comparator`.
+ #
+ # ~~~
+ # var map = new HashMap[Int, String]
+ # map[10] = "ten"
+ # map[2] = "two"
+ # map[1] = "one"
+ # assert map.values_sorted_by_key(default_comparator) == ["one", "two", "ten"]
+ # assert map.values_sorted_by_key(alpha_comparator) == ["one", "ten", "two"]
+ # ~~~
+ fun values_sorted_by_key(comparator: Comparator): Array[V]
+ do
+ var keys = self.keys.to_a
+ comparator.sort(keys)
+ return [for k in keys do self[k]]
+ end
+
+ # Return an array of all keys sorted with their values using `comparator`.
+ #
+ # ~~~
+ # var map = new HashMap[String, Int]
+ # map["ten"] = 10
+ # map["two"] = 2
+ # map["one"] = 1
+ # assert map.keys_sorted_by_values(default_comparator) == ["one", "two", "ten"]
+ # assert map.keys_sorted_by_values(alpha_comparator) == ["one", "ten", "two"]
+ # ~~~
+ #
+ # See: `to_map_comparator` to get the comparator used internally.
+ fun keys_sorted_by_values(comparator: Comparator): Array[K]
+ do
+ var keys = self.keys.to_a
+ var map_cmp = to_map_comparator(comparator)
+ map_cmp.sort(keys)
+ return keys
+ end
+
+ # A comparator that compares things with their values in self.
+ #
+ # See `MapComparator` for details.
+ fun to_map_comparator(comparator: Comparator): MapComparator[K, V] do return new MapComparator[K,V](self, comparator)
+end
+
+# A comparator that compares things with their values in a map.
+#
+# ~~~
+# var map = new HashMap[String, Int]
+# map["ten"] = 10
+# map["two"] = 2
+# map["one"] = 1
+#
+# var map_cmp = map.to_map_comparator(default_comparator)
+# var a = ["ten", "one", "two"]
+# map_cmp.sort(a)
+# assert a == ["one", "two", "ten"]
+# map_cmp = map.to_map_comparator(alpha_comparator)
+# map_cmp.sort(a)
+# assert a == ["one", "ten", "two"]
+# ~~~
+class MapComparator[K,V]
+ super Comparator
+
+ # What is compared are the keys of the values
+ redef type COMPARED: K
+
+ # The map that associates compared elements to the value used to compare them
+ var map: MapRead[K,V]
+
+ # The comparator used to compare values
+ var comparator: Comparator
+
+ redef fun compare(a,b) do return comparator.compare(map[a], map[b])
+end
+
# This comparator uses the operator `<=>` to compare objects.
# see `default_comparator` for an easy-to-use general stateless default comparator.
class DefaultComparator
# File descriptor of this file
fun fd: Int do return _file.fileno
+ redef fun close
+ do
+ if _file == null then return
+ if _file.address_is_null then
+ if last_error != null then return
+ last_error = new IOError("Cannot close unopened file")
+ return
+ end
+ var i = _file.io_close
+ if i != 0 then
+ last_error = new IOError("Close failed due to error {sys.errno.strerror}")
+ end
+ _file = null
+ end
+
# Sets the buffering mode for the current FileStream
#
# If the buf_size is <= 0, its value will be 512 by default
redef fun close
do
- if _file == null or _file.address_is_null then return
- var i = _file.io_close
+ super
_buffer.clear
end_reached = true
- _file = null
end
redef fun fill_buffer
end
end
+ # Creates a new File stream from a file descriptor
init from_fd(fd: Int) do
self.path = ""
prepare_buffer(1)
redef fun close
do
- if _file == null then return
- if _file.address_is_null then
- if last_error != null then return
- last_error = new IOError("Cannot close unopened write stream")
- _is_writable = false
- return
- end
- var i = _file.io_close
- if i != 0 then
- last_error = new IOError("Close failed due to error {sys.errno.strerror}")
- end
+ super
_is_writable = false
- _file = null
end
redef var is_writable = false
nitlanguage / nit.git / commitdiff