Class Util
Static helper methods.
This is a Lucene.NET EXPERIMENTAL API, use at your own risk
Inheritance
System.Object
Util
Assembly: Lucene.Net.dll
Syntax
public sealed class Util : object
Methods
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Get<T>(FST<T>, BytesRef)
Looks up the output for this input, or null if the
input is not accepted
Declaration
public static T Get<T>(FST<T> fst, BytesRef input)
Parameters
Returns
Type Parameters
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Get<T>(FST<T>, Int32sRef)
Looks up the output for this input, or null if the
input is not accepted.
Declaration
public static T Get<T>(FST<T> fst, Int32sRef input)
Parameters
Returns
Type Parameters
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GetByOutput(FST<Nullable<Int64>>, Int64)
Reverse lookup (lookup by output instead of by input),
in the special case when your FSTs outputs are
strictly ascending. This locates the input/output
pair where the output is equal to the target, and will
return null if that output does not exist.
NOTE: this only works with , only
works when the outputs are ascending in order with
the inputs.
For example, simple ordinals (0, 1,
2, ...), or file offets (when appending to a file)
fit this.
Declaration
public static Int32sRef GetByOutput(FST<long?> fst, long targetOutput)
Parameters
| Type |
Name |
Description |
| FST<System.Nullable<System.Int64>> |
fst |
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| System.Int64 |
targetOutput |
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Returns
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GetByOutput(FST<Nullable<Int64>>, Int64, FST.BytesReader, FST.Arc<Nullable<Int64>>, FST.Arc<Nullable<Int64>>, Int32sRef)
Declaration
public static Int32sRef GetByOutput(FST<long?> fst, long targetOutput, FST.BytesReader in, FST.Arc<long?> arc, FST.Arc<long?> scratchArc, Int32sRef result)
Parameters
| Type |
Name |
Description |
| FST<System.Nullable<System.Int64>> |
fst |
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| System.Int64 |
targetOutput |
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| FST.BytesReader |
in |
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| FST.Arc<System.Nullable<System.Int64>> |
arc |
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| FST.Arc<System.Nullable<System.Int64>> |
scratchArc |
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| Int32sRef |
result |
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Returns
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ReadCeilArc<T>(Int32, FST<T>, FST.Arc<T>, FST.Arc<T>, FST.BytesReader)
Reads the first arc greater or equal that the given label into the provided
arc in place and returns it iff found, otherwise return null.
Declaration
public static FST.Arc<T> ReadCeilArc<T>(int label, FST<T> fst, FST.Arc<T> follow, FST.Arc<T> arc, FST.BytesReader in)
Parameters
| Type |
Name |
Description |
| System.Int32 |
label |
the label to ceil on
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| FST<T> |
fst |
the fst to operate on
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| FST.Arc<T> |
follow |
the arc to follow reading the label from
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| FST.Arc<T> |
arc |
the arc to read into in place
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| FST.BytesReader |
in |
the fst's FST.BytesReader
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Returns
Type Parameters
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ShortestPaths<T>(FST<T>, FST.Arc<T>, T, IComparer<T>, Int32, Boolean)
Starting from node, find the top N min cost
completions to a final node.
Declaration
public static Util.TopResults<T> ShortestPaths<T>(FST<T> fst, FST.Arc<T> fromNode, T startOutput, IComparer<T> comparer, int topN, bool allowEmptyString)
Parameters
| Type |
Name |
Description |
| FST<T> |
fst |
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| FST.Arc<T> |
fromNode |
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| T |
startOutput |
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| IComparer<T> |
comparer |
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| System.Int32 |
topN |
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| System.Boolean |
allowEmptyString |
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Returns
Type Parameters
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ToBytesRef(Int32sRef, BytesRef)
Declaration
public static BytesRef ToBytesRef(Int32sRef input, BytesRef scratch)
Parameters
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ToDot<T>(FST<T>, TextWriter, Boolean, Boolean)
Dumps an FST<T> to a GraphViz's dot language description
for visualization. Example of use:
using (TextWriter sw = new StreamWriter("out.dot"))
{
Util.ToDot(fst, sw, true, true);
}
and then, from command line:
dot -Tpng -o out.png out.dot
Note: larger FSTs (a few thousand nodes) won't even
render, don't bother. If the FST is > 2.1 GB in size
then this method will throw strange exceptions.
See also http://www.graphviz.org/.
Declaration
public static void ToDot<T>(FST<T> fst, TextWriter out, bool sameRank, bool labelStates)
Parameters
| Type |
Name |
Description |
| FST<T> |
fst |
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| TextWriter |
out |
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| System.Boolean |
sameRank |
If true, the resulting dot file will try
to order states in layers of breadth-first traversal. This may
mess up arcs, but makes the output FST's structure a bit clearer.
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| System.Boolean |
labelStates |
If true states will have labels equal to their offsets in their
binary format. Expands the graph considerably.
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Type Parameters
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ToInt32sRef(BytesRef, Int32sRef)
Just takes unsigned byte values from the BytesRef and
converts into an Int32sRef.
NOTE: This was toIntsRef() in Lucene
Declaration
public static Int32sRef ToInt32sRef(BytesRef input, Int32sRef scratch)
Parameters
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ToUTF16(String, Int32sRef)
Just maps each UTF16 unit (char) to the s in an
Int32sRef.
Declaration
public static Int32sRef ToUTF16(string s, Int32sRef scratch)
Parameters
| Type |
Name |
Description |
| System.String |
s |
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| Int32sRef |
scratch |
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Returns
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ToUTF32(Char[], Int32, Int32, Int32sRef)
Decodes the Unicode codepoints from the provided
char[] and places them in the provided scratch
Int32sRef, which must not be null, returning it.
Declaration
public static Int32sRef ToUTF32(char[] s, int offset, int length, Int32sRef scratch)
Parameters
| Type |
Name |
Description |
| System.Char[] |
s |
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| System.Int32 |
offset |
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| System.Int32 |
length |
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| Int32sRef |
scratch |
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Returns
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ToUTF32(String, Int32sRef)
Decodes the Unicode codepoints from the provided
ICharSequence and places them in the provided scratch
Int32sRef, which must not be null, returning it.
Declaration
public static Int32sRef ToUTF32(string s, Int32sRef scratch)
Parameters
| Type |
Name |
Description |
| System.String |
s |
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| Int32sRef |
scratch |
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Returns