relations.py

#!/usr/bin/env python
#coding=utf-8

'''
Definition of Relations class. It stores the graph constructed so far.
It provides a DFS method that is used to retrieve the triples, which in turn are used to 
output the AMR graph. 

@author: Marco Damonte (m.damonte@sms.ed.ac.uk)
@since: 03-10-16
'''

from collections import defaultdict
from node import Node
import copy

class Relations:

    def __init__(self, initial = []):
        self.children = defaultdict(list)
        self.parents = defaultdict(list)
        self.list = []

        for (n1, label, n2) in initial:
            self.add(n1, n2, label)

    def __eq__(self, other):
        return self.children == other.children and self.parents == other.parents

    def __repr__(self):
        return str(self.list)

    def add(self, node1, node2, label):
        if (node1,label,node2) not in self.list:
            self.list.append((node1,label,node2))

        if (node2,label) not in self.children[node1]:
            self.children[node1].append((node2,label))
        if (node1,label) not in self.parents[node2]:
            self.parents[node2].append((node1,label))

    def dfs(self, root, visited):
        lst = []
        for (child,label) in self.children[root]:
            lst.append((root.variable(),root.amrconcept(),label,child.variable(),child.amrconcept()))
            if child not in visited:
                visited.append(child)
                lst.extend(self.dfs(child,visited))
        return lst

    def _isConnToRoot(self, node, visited):
        if node in visited:
            return False
        visited.append(node)

        if node.isRoot:
            return True
        for (father,_) in self.parents[node]:
            if self._isConnToRoot(father, visited):
                return True
        return False


    def est_depth(self, node, other = None):
        n = 0
        seen = []
        while node in self.parents and len(self.parents[node]) > 0:
            for i in self.parents[node]:
                node, _ = i
                if node in seen:
                    return n
                seen.append(node)
                break
            if node != other:
                n += 1
        return n

    def est_depth_down(self, node, other = None):
        n = 0
        seen = []
        while node in self.children and len(self.children[node]) > 0:
            for i in self.children[node]:
                node, _ = i
                if node in seen:
                    return n
                seen.append(node)
                break
            if node != other:
                n += 1
        return n

    def triples(self):
        root = Node(True)
        for node in copy.deepcopy(self.children):
            if node is None:
                continue
            if self._isConnToRoot(node, []) == False and len(self.children[node]) > 0:
                self.add(Node(True), node, ":top")
        lst = self.dfs(root,[])
        if len(self.children[root]) > 1:
            counter = 1
            lst2 = []
            lst2.append(("TOP","",":top","mu","multi-sentence"))
            for v1,c1,l,v2,c2 in lst:
                if v1 == "TOP":
                    v1 = "mu"
                    c1 = "multi-sentence"
                    l = ":snt" + str(counter)
                    counter += 1
                lst2.append((v1,c1,l,v2,c2))
            return lst2
        return lst

    def _leftmost(self, node, direction, other = None):
        if node is not None:
            if direction == "child":
                lst = self.children[node]
            else:
                lst = self.parents[node]
            if len(lst) > 0:
                candidate = None
                minindex = float("inf")
                for item in lst:
                    if item[0].isRoot:
                        if item[0] != other:
                            return item
                    elif item[0].token.index < minindex and item[0] != other:
                        candidate = item
                        minindex = item[0].token.index
                return candidate
        return None

    def _rightmost(self, node, direction, other = None):
        if node is not None:
            if direction == "child":
                lst = self.children[node]
            else:
                lst = self.parents[node]
            if len(lst) > 0:
                candidate = None
                maxindex = -1
                for item in lst:
                    if item[0].isRoot and candidate is None and item[0] != other:
                        candidate = item
                        maxindex = -1
                    elif item[0].isRoot == False and item[0].token.index > maxindex and item[0] != other:
                        candidate = item
                        maxindex = item[0].token.index
                return candidate
        return None

    def leftmost_child(self, node, other = None):
        child = self._leftmost(node, "child", other)
        if child == None:
            return "<NULL>"
        if child[0].isConst:
            return child[0].constant
        elif child[0].isRoot:
            return "<TOP>"
        else:
            return child[0].concept

    def leftmost_grandchild(self, node, other = None):
        child = self._leftmost(node, "child", other)
        if child is not None:
            grandchild = self._leftmost(child[0], "child", other)
            if grandchild is not None:
                if grandchild[0].isConst:
                    return grandchild[0].constant
                elif grandchild[0].isRoot:
                    return "<TOP>"
                else:
                    return grandchild[0].concept
        return "<NULL>"

    def rightmost_child(self, node, other = None):
        child = self._rightmost(node, "child", other)
        if child == None:
            return "<NULL>"
        if child[0].isConst:
            return child[0].constant
        elif child[0].isRoot:
            return "<TOP>"
        else:
            return child[0].concept

    def rightmost_grandchild(self, node, other = None):
        child = self._rightmost(node, "child", other)
        if child is not None:
            grandchild = self._rightmost(child[0], "child", other)
            if grandchild is not None:
                if grandchild[0].isConst:
                    return grandchild[0].constant
                elif grandchild[0].isRoot:
                    return "<TOP>"
                else:
                    return grandchild[0].concept
        return "<NULL>"

    def leftmost_parent(self, node, other = None):
        parent = self._leftmost(node, "parent", other)
        if parent == None:
            return "<NULL>"
        if parent[0].isConst:
            return parent[0].constant
        elif parent[0].isRoot:
            return "<TOP>"
        else:
            return parent[0].concept

    def rightmost_parent(self, node, other = None):
        parent = self._rightmost(node, "parent", other)
        if parent == None:
            return "<NULL>"
        if parent[0].isConst:
            return parent[0].constant
        elif parent[0].isRoot:
            return "<TOP>"
        else:
            return parent[0].concept

    def isBasterd(self, node):
        return len(self.parents[node]) == 0

    def children_nodes(self, node):
        return [c[0] for c in self.children[node]]

    def isRel(self, node1, node2, boolean = False):
        assert ((isinstance(node1, Node) or node1 is None) and (isinstance(node2, Node) or node2 is None))

        if node1 is None:
            return None
        if node2 is None:
            return None

        for (node, label) in self.children[node1]:
            if node == node2:
                return label
        return None