TermMapping class abstract

Maps from a String to a sequence of terms.

f : S ↠ S^ℕ

such that

• S is the set of all non empty Strings
• ℕ is the set of Natural numbers
• S^ℕ is the set of all functions ℕ ↦ S

The sequence of terms is pairwise distinct, i.e. a term can occur only once in the returned sequence.

Suggester works by tokenising both suggestions and input using a Term Mapping and finding partial matches between them via prefix searching.

For example a TermMapping that groups inputs and suggestions into sequences of letters and numbers:

print(AlphaOrNumeric().map('[e-mail]', false, false));

{armani, klein, 3, veda, io}

TermMapping that groups inputs and suggestions into NGrams of size 3, i.e. trigrams.

print(Ngrams(3).map('[e-mail]', false, false));

{arm, rma, man, ani, ni., i.k, .kl, kle, lei, ein, in3, n3@, 3@v, @ve, ved, eda, da., a.i, .io}

Implementers

• Alpha
• AlphaAndNumeric
• AlphaOrNumeric
• Ngrams
• Tokens

Constructors

TermMapping(Iterable<String> map(String entry, bool caseSensitive, bool unicode), double termDecay)

Construct TermMapping with specified map function.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

map → Iterable<String> Function(String entry, bool caseSensitive, bool unicode)

Performs mapping

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

termDecay → double

Exponential decay value for term proximality calculation.

final

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

tpFromTermIdx(int termIdx) → double

Weight terms inversely according to their proximality. Exponential decay of termIdx ensures that proximal terms are heavily weighted compared to distal.

Operators

operator ==(Object other) → bool

The equality operator.

inherited