Module tf.core.nodes
Node organization
This module is about ordering nodes in terms of the slot nodes they are attached to.
Canonical Order
Nodes are linked to subsets of slots, and there is a canonical ordering on subsets of integers that is inherited by the nodes.
The canonical order is a way to sort the nodes in your corpus in such a way that you can enumerate all nodes in the order you encounter them if you walk through your corpus.
 Formally
 A node A comes before a node B if A contains the smallest slot that occurs in only one of A and B.
Briefly this means:
 embedder nodes come before the nodes that lie embedded in them;
 earlier stuff comes before later stuff,
 if a verse coincides with a sentence, the verse comes before the sentence, because verses generally contain sentences and not the other way round;
 if two objects are intersecting, but none embeds the other, the one with the smallest slot that does not occur in the other, comes first.
first things first, big things first
That means, roughly, that you start with a book node (Genesis), then a chapter node (Genesis 1), then a verse node, Genesis 1:1, then a sentence node, then a clause node, a phrase node, and the first word node. Then follow all word nodes in the first phrase, then the phrase node of the second phrase, followed by the word nodes in that phrase. When ever you enter a higher structure, you will first get the node corresponding to that structure, and after that the nodes corresponding to the building blocks of that structure.
This concept follows the intuition that slot sets with smaller elements come before slot set with bigger elements, and embedding slot sets come before embedded slot sets. Hence, if you enumerate a set of nodes that happens to constitute a tree hierarchy based on slot set embedding, and you enumerate those nodes in the slot set order, you will walk the tree in preorder.
This order is a modification of the one as described in (Doedens 1994, 3.6.3).
Doedens, CristJan (1994), Text Databases. One Database Model and Several Retrieval Languages, number 14 in Language and Computers, Editions Rodopi, Amsterdam, Netherlands and Atlanta, USA. ISBN: 9051837291, https://books.google.nl/books?id=9ggOBRz1dO4C. The order as defined by Doedens corresponds to walking trees in postorder.
For a lot of processing, it is handy to have a the stack of embedding elements available when working with an element. That is the advantage of preorder over postorder. It is very much like SAX parsing in the XML world.
Expand source code Browse git
"""
# Node organization
This module is about ordering nodes in terms of the slot nodes they are attached to.
## Canonical Order
Nodes are linked to subsets of slots, and there is a canonical ordering
on subsets of integers that is inherited by the nodes.
The canonical order is a way to sort the nodes in your corpus in such a way
that you can enumerate all nodes in the order you encounter them if you
walk through your corpus.
Formally
: A node *A* comes before a node *B* if *A* contains the smallest slot
that occurs in only one of *A* and *B*.
Briefly this means:
* embedder nodes come before the nodes that lie embedded in them;
* earlier stuff comes before later stuff,
* if a verse coincides with a sentence, the verse comes before the sentence,
because verses generally contain sentences and not the other way round;
* if two objects are intersecting, but none embeds the other, the one with the
smallest slot that does not occur in the other, comes first.
!!! note "first things first, big things first"
That means, roughly, that you start with a
book node (Genesis), then a chapter node (Genesis 1), then a verse node, Genesis
1:1, then a sentence node, then a clause node, a phrase node, and the first word
node. Then follow all word nodes in the first phrase, then the phrase node of
the second phrase, followed by the word nodes in that phrase. When ever you
enter a higher structure, you will first get the node corresponding to that
structure, and after that the nodes corresponding to the building blocks of that
structure.
This concept follows the intuition that slot sets with smaller elements come
before slot set with bigger elements, and embedding slot sets come before
embedded slot sets. Hence, if you enumerate a set of nodes that happens to
constitute a tree hierarchy based on slot set embedding, and you enumerate those
nodes in the slot set order, you will walk the tree in preorder.
This order is a modification of the one as described in (Doedens 1994, 3.6.3).
![fabric](../images/DoedensLO.png)
> Doedens, CristJan (1994), *Text Databases. One Database Model and Several
> Retrieval Languages*, number 14 in Language and Computers, Editions Rodopi,
> Amsterdam, Netherlands and Atlanta, USA. ISBN: 9051837291,
> https://books.google.nl/books?id=9ggOBRz1dO4C. The order as defined by
> Doedens corresponds to walking trees in postorder.
For a lot of processing, it is handy to have a the stack of embedding elements
available when working with an element. That is the advantage of preorder over
postorder. It is very much like SAX parsing in the XML world.
"""
import functools
class Nodes:
def __init__(self, api):
self.api = api
C = api.C
Crank = C.rank.data
self.otypeRank = {d[0]: i for (i, d) in enumerate(reversed(C.levels.data))}
"""Dictionary that provides a ranking of the node types.
The node types are ordered in `C.levels.data`, and if you reverse that list,
you get the rank of a type by looking at the position in which that type occurs.
The *slotType* has rank 0 (`otypeRank[F.otype.slotType] == 0`),
and the more comprehensive a type is, the higher its rank.
"""
self.sortKey = lambda n: Crank[n  1]
"""Sort key function for the canonical ordering between nodes.
!!! hint "usage"
The following two pieces of code do the same thing:
`sortNodes(nodeSet)` and `sorted(nodeSet, key=sortKey)`.
See Also

tf.core.nodes: canonical ordering
tf.core.nodes.Nodes.sortNodes: sorting nodes
"""
self.sortKeyTuple = lambda tup: tuple(Crank[n  1] for n in tup)
"""Sort key function for the canonical ordering between tuples of nodes.
It applies `sortKey` to each member of the tuple.
Handy to sort search results. We can sort them in canonical order like this:
sorted(results, key=lambda tup: tuple(sortKey(n) for n in tup))
This is exactly what `sortKeyTuple` does, but then a bit more efficient:
sorted(results, key=sortKeyTuple)
See Also

tf.core.nodes: canonical ordering
"""
(sortKeyChunk, sortKeyChunkLength) = self.makeSortKeyChunk()
self.sortKeyChunk = sortKeyChunk
"""Sort key function for the canonical ordering between chunks of nodes.
sorted(chunks, key=sortKeyChunk)
A chunk is a tuple consisting of a node and a subset of its slots.
Mostly, this subset of slots is contiguous (no gaps), and mostly it is
maximal: the slots immediately before and after the chunk do not belong to the node.
But the sortkey also works if these conditions are not met.
Notes

The use case for this function is that we have a bunch of nodes,
each linked to a set of slots.
For each node, we have split its slot set in maximal contiguous parts, its chunks.
Now we want to order those chunks in the canonical ordering.
See Also

tf.core.nodes: canonical ordering
"""
self.sortKeyChunkLength = sortKeyChunkLength
def makeSortKeyChunk(self):
api = self.api
fOtype = api.F.otype
otypeRank = self.otypeRank
fOtypev = fOtype.v
def beforePosition(chunk1, chunk2):
(n1, (b1, e1)) = chunk1
(n2, (b2, e2)) = chunk2
if b1 < b2:
return 1
elif b1 > b2:
return 1
r1 = otypeRank[fOtypev(n1)]
r2 = otypeRank[fOtypev(n2)]
if r1 > r2:
return 1
elif r1 < r2:
return 1
return (
1
if e1 > e2
else 1
if e1 < e2
else 1
if n1 < n2
else 1
if n1 > n2
else 0
)
def beforeLength(chunk1, chunk2):
(n1, (b1, e1)) = chunk1
(n2, (b2, e2)) = chunk2
size1 = e1  b1
size2 = e2  b2
if size1 > size2:
return 1
elif size2 > size1:
return 1
elif b1 < b2:
return 1
elif b1 > b2:
return 1
r1 = otypeRank[fOtypev(n1)]
r2 = otypeRank[fOtypev(n2)]
if r2 > r1:
return 1
elif r1 > r2:
return 1
return 1 if n1 < n2 else 1 if n1 > n2 else 0
return (
functools.cmp_to_key(beforePosition),
functools.cmp_to_key(beforeLength),
)
def sortNodes(self, nodeSet):
"""Delivers a tuple of nodes sorted by the *canonical ordering*.
Parameters

nodeSet: iterable
An iterable of nodes to be sorted.
Returns

list
The sorted nodes as list
See Also

tf.core.nodes: canonical ordering
"""
api = self.api
Crank = api.C.rank.data
return sorted(nodeSet, key=lambda n: Crank[n  1])
def walk(self, nodes=None, events=False):
"""Generates all nodes in the *canonical order*.
(`tf.core.nodes`)
By `walk()` you traverse all nodes of your corpus
in a very natural order. See `tf.core.nodes`.
The order is much like walking a tree in preorder: first parents,
then children from left to right.
The thing is: in general the nodes do not form a tree, but a more
liberal structure: a graph.
But even then we can order the nodes in such a way that nodes that embed
slots from other nodes come before those other nodes, provided those other
nodes start later.
When we generate those nodes and consume them, we now when each node starts,
but we loose track of where exactly they end.
To remedy that, you can call this function with `events=True`.
In that case, a stream of events is generated, where each event has the
form `(node, False)` or `(node, True)`, where `False` means: beginning of
node and `True` means: end of node.
In case of slot nodes, only one event per slot is generated: `(node, None)`.
!!! hint "More ways of walking"
Under `tf.core.nodefeature.NodeFeatures` there is another convenient way
to walk through subsets of nodes.
Parameters

nodes: iterable of int, optional None
If `None`, walks through all nodes of the corpus in canonical order.
Otherwise, walks through the given nodes in canonical order.
events: boolean, optional False
If True, wraps the generated nodes in event tuples as described above.
Returns

nodes: int
One at a time.
"""
api = self.api
C = api.C
if nodes is None:
walkNodes = C.order.data
else:
walkNodes = self.sortNodes(nodes)
walkNodeSet = set(nodes)
if events:
endSlots = C.boundary.data[1]
otype = api.F.otype
Fotypev = otype.v
slotType = otype.slotType
for n in walkNodes:
if Fotypev(n) == slotType:
yield (n, None)
for m in reversed(endSlots[n  1]):
if nodes is None or m in walkNodeSet:
yield (m, True)
else:
yield (n, False)
else:
for n in walkNodes:
yield n
Classes
class Nodes (api)

Expand source code Browse git
class Nodes: def __init__(self, api): self.api = api C = api.C Crank = C.rank.data self.otypeRank = {d[0]: i for (i, d) in enumerate(reversed(C.levels.data))} """Dictionary that provides a ranking of the node types. The node types are ordered in `C.levels.data`, and if you reverse that list, you get the rank of a type by looking at the position in which that type occurs. The *slotType* has rank 0 (`otypeRank[F.otype.slotType] == 0`), and the more comprehensive a type is, the higher its rank. """ self.sortKey = lambda n: Crank[n  1] """Sort key function for the canonical ordering between nodes. !!! hint "usage" The following two pieces of code do the same thing: `sortNodes(nodeSet)` and `sorted(nodeSet, key=sortKey)`. See Also  tf.core.nodes: canonical ordering tf.core.nodes.Nodes.sortNodes: sorting nodes """ self.sortKeyTuple = lambda tup: tuple(Crank[n  1] for n in tup) """Sort key function for the canonical ordering between tuples of nodes. It applies `sortKey` to each member of the tuple. Handy to sort search results. We can sort them in canonical order like this: sorted(results, key=lambda tup: tuple(sortKey(n) for n in tup)) This is exactly what `sortKeyTuple` does, but then a bit more efficient: sorted(results, key=sortKeyTuple) See Also  tf.core.nodes: canonical ordering """ (sortKeyChunk, sortKeyChunkLength) = self.makeSortKeyChunk() self.sortKeyChunk = sortKeyChunk """Sort key function for the canonical ordering between chunks of nodes. sorted(chunks, key=sortKeyChunk) A chunk is a tuple consisting of a node and a subset of its slots. Mostly, this subset of slots is contiguous (no gaps), and mostly it is maximal: the slots immediately before and after the chunk do not belong to the node. But the sortkey also works if these conditions are not met. Notes  The use case for this function is that we have a bunch of nodes, each linked to a set of slots. For each node, we have split its slot set in maximal contiguous parts, its chunks. Now we want to order those chunks in the canonical ordering. See Also  tf.core.nodes: canonical ordering """ self.sortKeyChunkLength = sortKeyChunkLength def makeSortKeyChunk(self): api = self.api fOtype = api.F.otype otypeRank = self.otypeRank fOtypev = fOtype.v def beforePosition(chunk1, chunk2): (n1, (b1, e1)) = chunk1 (n2, (b2, e2)) = chunk2 if b1 < b2: return 1 elif b1 > b2: return 1 r1 = otypeRank[fOtypev(n1)] r2 = otypeRank[fOtypev(n2)] if r1 > r2: return 1 elif r1 < r2: return 1 return ( 1 if e1 > e2 else 1 if e1 < e2 else 1 if n1 < n2 else 1 if n1 > n2 else 0 ) def beforeLength(chunk1, chunk2): (n1, (b1, e1)) = chunk1 (n2, (b2, e2)) = chunk2 size1 = e1  b1 size2 = e2  b2 if size1 > size2: return 1 elif size2 > size1: return 1 elif b1 < b2: return 1 elif b1 > b2: return 1 r1 = otypeRank[fOtypev(n1)] r2 = otypeRank[fOtypev(n2)] if r2 > r1: return 1 elif r1 > r2: return 1 return 1 if n1 < n2 else 1 if n1 > n2 else 0 return ( functools.cmp_to_key(beforePosition), functools.cmp_to_key(beforeLength), ) def sortNodes(self, nodeSet): """Delivers a tuple of nodes sorted by the *canonical ordering*. Parameters  nodeSet: iterable An iterable of nodes to be sorted. Returns  list The sorted nodes as list See Also  tf.core.nodes: canonical ordering """ api = self.api Crank = api.C.rank.data return sorted(nodeSet, key=lambda n: Crank[n  1]) def walk(self, nodes=None, events=False): """Generates all nodes in the *canonical order*. (`tf.core.nodes`) By `walk()` you traverse all nodes of your corpus in a very natural order. See `tf.core.nodes`. The order is much like walking a tree in preorder: first parents, then children from left to right. The thing is: in general the nodes do not form a tree, but a more liberal structure: a graph. But even then we can order the nodes in such a way that nodes that embed slots from other nodes come before those other nodes, provided those other nodes start later. When we generate those nodes and consume them, we now when each node starts, but we loose track of where exactly they end. To remedy that, you can call this function with `events=True`. In that case, a stream of events is generated, where each event has the form `(node, False)` or `(node, True)`, where `False` means: beginning of node and `True` means: end of node. In case of slot nodes, only one event per slot is generated: `(node, None)`. !!! hint "More ways of walking" Under `tf.core.nodefeature.NodeFeatures` there is another convenient way to walk through subsets of nodes. Parameters  nodes: iterable of int, optional None If `None`, walks through all nodes of the corpus in canonical order. Otherwise, walks through the given nodes in canonical order. events: boolean, optional False If True, wraps the generated nodes in event tuples as described above. Returns  nodes: int One at a time. """ api = self.api C = api.C if nodes is None: walkNodes = C.order.data else: walkNodes = self.sortNodes(nodes) walkNodeSet = set(nodes) if events: endSlots = C.boundary.data[1] otype = api.F.otype Fotypev = otype.v slotType = otype.slotType for n in walkNodes: if Fotypev(n) == slotType: yield (n, None) for m in reversed(endSlots[n  1]): if nodes is None or m in walkNodeSet: yield (m, True) else: yield (n, False) else: for n in walkNodes: yield n
Instance variables
var otypeRank

Dictionary that provides a ranking of the node types.
The node types are ordered in
C.levels.data
, and if you reverse that list, you get the rank of a type by looking at the position in which that type occurs.The slotType has rank 0 (
otypeRank[F.otype.slotType] == 0
), and the more comprehensive a type is, the higher its rank. var sortKey

Sort key function for the canonical ordering between nodes.
usage
The following two pieces of code do the same thing:
sortNodes(nodeSet)
andsorted(nodeSet, key=sortKey)
.See Also
tf.core.nodes
 canonical ordering
Nodes.sortNodes()
 sorting nodes
var sortKeyChunk

Sort key function for the canonical ordering between chunks of nodes.
sorted(chunks, key=sortKeyChunk)
A chunk is a tuple consisting of a node and a subset of its slots. Mostly, this subset of slots is contiguous (no gaps), and mostly it is maximal: the slots immediately before and after the chunk do not belong to the node.
But the sortkey also works if these conditions are not met.
Notes
The use case for this function is that we have a bunch of nodes, each linked to a set of slots. For each node, we have split its slot set in maximal contiguous parts, its chunks. Now we want to order those chunks in the canonical ordering.
See Also
tf.core.nodes
 canonical ordering
var sortKeyTuple

Sort key function for the canonical ordering between tuples of nodes. It applies
sortKey
to each member of the tuple. Handy to sort search results. We can sort them in canonical order like this:sorted(results, key=lambda tup: tuple(sortKey(n) for n in tup))
This is exactly what
sortKeyTuple
does, but then a bit more efficient:sorted(results, key=sortKeyTuple)
See Also
tf.core.nodes
 canonical ordering
Methods
def makeSortKeyChunk(self)

Expand source code Browse git
def makeSortKeyChunk(self): api = self.api fOtype = api.F.otype otypeRank = self.otypeRank fOtypev = fOtype.v def beforePosition(chunk1, chunk2): (n1, (b1, e1)) = chunk1 (n2, (b2, e2)) = chunk2 if b1 < b2: return 1 elif b1 > b2: return 1 r1 = otypeRank[fOtypev(n1)] r2 = otypeRank[fOtypev(n2)] if r1 > r2: return 1 elif r1 < r2: return 1 return ( 1 if e1 > e2 else 1 if e1 < e2 else 1 if n1 < n2 else 1 if n1 > n2 else 0 ) def beforeLength(chunk1, chunk2): (n1, (b1, e1)) = chunk1 (n2, (b2, e2)) = chunk2 size1 = e1  b1 size2 = e2  b2 if size1 > size2: return 1 elif size2 > size1: return 1 elif b1 < b2: return 1 elif b1 > b2: return 1 r1 = otypeRank[fOtypev(n1)] r2 = otypeRank[fOtypev(n2)] if r2 > r1: return 1 elif r1 > r2: return 1 return 1 if n1 < n2 else 1 if n1 > n2 else 0 return ( functools.cmp_to_key(beforePosition), functools.cmp_to_key(beforeLength), )
def sortNodes(self, nodeSet)

Delivers a tuple of nodes sorted by the canonical ordering.
Parameters
nodeSet
:iterable
 An iterable of nodes to be sorted.
Returns
list
 The sorted nodes as list
See Also
tf.core.nodes
 canonical ordering
Expand source code Browse git
def sortNodes(self, nodeSet): """Delivers a tuple of nodes sorted by the *canonical ordering*. Parameters  nodeSet: iterable An iterable of nodes to be sorted. Returns  list The sorted nodes as list See Also  tf.core.nodes: canonical ordering """ api = self.api Crank = api.C.rank.data return sorted(nodeSet, key=lambda n: Crank[n  1])
def walk(self, nodes=None, events=False)

Generates all nodes in the canonical order. (
tf.core.nodes
)By
walk()
you traverse all nodes of your corpus in a very natural order. Seetf.core.nodes
.The order is much like walking a tree in preorder: first parents, then children from left to right.
The thing is: in general the nodes do not form a tree, but a more liberal structure: a graph.
But even then we can order the nodes in such a way that nodes that embed slots from other nodes come before those other nodes, provided those other nodes start later.
When we generate those nodes and consume them, we now when each node starts, but we loose track of where exactly they end.
To remedy that, you can call this function with
events=True
. In that case, a stream of events is generated, where each event has the form(node, False)
or(node, True)
, whereFalse
means: beginning of node andTrue
means: end of node.In case of slot nodes, only one event per slot is generated:
(node, None)
.More ways of walking
Under
NodeFeatures
there is another convenient way to walk through subsets of nodes.Parameters
nodes
:iterable
ofint
, optionalNone
 If
None
, walks through all nodes of the corpus in canonical order. Otherwise, walks through the given nodes in canonical order. events
:boolean
, optionalFalse
 If True, wraps the generated nodes in event tuples as described above.
Returns
nodes
:int
 One at a time.
Expand source code Browse git
def walk(self, nodes=None, events=False): """Generates all nodes in the *canonical order*. (`tf.core.nodes`) By `walk()` you traverse all nodes of your corpus in a very natural order. See `tf.core.nodes`. The order is much like walking a tree in preorder: first parents, then children from left to right. The thing is: in general the nodes do not form a tree, but a more liberal structure: a graph. But even then we can order the nodes in such a way that nodes that embed slots from other nodes come before those other nodes, provided those other nodes start later. When we generate those nodes and consume them, we now when each node starts, but we loose track of where exactly they end. To remedy that, you can call this function with `events=True`. In that case, a stream of events is generated, where each event has the form `(node, False)` or `(node, True)`, where `False` means: beginning of node and `True` means: end of node. In case of slot nodes, only one event per slot is generated: `(node, None)`. !!! hint "More ways of walking" Under `tf.core.nodefeature.NodeFeatures` there is another convenient way to walk through subsets of nodes. Parameters  nodes: iterable of int, optional None If `None`, walks through all nodes of the corpus in canonical order. Otherwise, walks through the given nodes in canonical order. events: boolean, optional False If True, wraps the generated nodes in event tuples as described above. Returns  nodes: int One at a time. """ api = self.api C = api.C if nodes is None: walkNodes = C.order.data else: walkNodes = self.sortNodes(nodes) walkNodeSet = set(nodes) if events: endSlots = C.boundary.data[1] otype = api.F.otype Fotypev = otype.v slotType = otype.slotType for n in walkNodes: if Fotypev(n) == slotType: yield (n, None) for m in reversed(endSlots[n  1]): if nodes is None or m in walkNodeSet: yield (m, True) else: yield (n, False) else: for n in walkNodes: yield n