1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2012 Jean Privat <jean@pryen.org>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # management and display of ordered trees
20 # Generic structure to manage and display an ordered tree
22 # Ordered tree are tree where the elements of a same parent are in a specific order
24 # The class can be used as it to work with generic tree.
25 # The class can also be specialized to provide more specific behavior.
26 class OrderedTree[E
: Object]
28 var roots
= new Array[E
]
29 var sub
= new HashMap[E
, Array[E
]]
31 # Add a new element `e` in the tree
32 # `p` is the parent of `e`.
33 # if `p` is null, then `e` is a root element.
35 # By defauld, the elements with a same parent
36 # are displayed in the order they are added.
38 # The `sort_with` method can be used reorder elements
39 fun add
(p
: nullable E
, e
: E
)
43 else if sub
.has_key
(p
) then
50 # print the full tree on `o`
51 # Write a ASCII-style tree and use the `display` method to label elements
52 fun pretty
(o
: OStream)
62 private fun sub_pretty
(o
: OStream, e
: E
, prefix
: String)
64 if not sub
.has_key
(e
) then return
69 o
.write
"{prefix}|--{display(e2)}\n"
70 sub_pretty
(o
, e2
, prefix
+"| ")
72 o
.write
"{prefix}`--{display(e2)}\n"
73 sub_pretty
(o
, e2
, prefix
+" ")
78 # Sort roots and other elements using a comparator method
79 # This method basically sorts roots then each group of children
80 fun sort_with
(comparator
: AbstractSorter[E
])
82 comparator
.sort
(roots
)
83 for a
in sub
.values
do
88 # How to display a specific element of the tree
89 # By defaut, uses `to_s`
91 # Subclasses should redefine this method to provide a specific output
92 fun display
(e
: E
): String do return e
.to_s