Query-Based Item-List Reduction for JavaScript
Sieving is a JavaScript library for reducing/filtering a JavaScript list of items, based on a simple simple query language. It is intended to be used for item list filtering or item list searching purposes within Browser or Node.js environments. Internally, Sieving is based on a full-blown query parser, supports optional fuzzy matching and namespacing of items, and supports union, intersection and subtraction of the result sets.
A query like...
foo bar^ +baz -quux, baz
...on a result set basis and mathematically means...
(((MATCH("foo") ∩ BOOST(MATCH("bar"), 1)) ∪ MATCH("baz")) ∖ MATCH("quux")) ∪ MATCH("baz")
...or expressed in a functional way:
UNION(
SUBTRACT(
UNION(
INTERSECT(
MATCH("foo"),
BOOST(MATCH("bar"), 1)),
MATCH("baz")),
MATCH("quux")),
MATCH("baz"))
$ npm install sievingconst Sieving = require("sieving")
let items = [ "foo", "bar", "baz", "quux", "foo bar", "foo baz", "foo quux", "foo bar quux" ]
/* step-by-step usage */
let sieving = new Sieving()
sieving.parse("foo +bar -quux, baz^")
console.log(sieving.format())
console.log(sieving.dump())
let result = sieving.sieve(items)
console.log(result)
/* all-in-one usage */
result = Sieving.sieve(items, "foo +bar -quux, baz^")
console.log(result)Output:
queries [1,1]
├── query [1,1]
│ ├── term (value: "foo", type: "bare") [1,1]
│ ├── term (op: "union", value: "bar", type: "bare") [1,5]
│ └── term (op: "subtraction", value: "quux", type: "bare") [1,10]
└── query [1,17]
└── term (value: "baz", type: "bare", boost: 1) [1,17]
[ 'baz', 'foo', 'foo bar', 'foo baz', 'bar' ]
[ 'baz', 'foo', 'foo bar', 'foo baz', 'bar' ]
const { sieve } = require("sieving")
const { expect } = require("chai")
let items = [ "foo", "bar", "baz", "quux", "foo bar baz quux" ]
expect(sieve(items, "foo")) .deep.equal([ "foo", "foo bar baz quux" ])
expect(sieve(items, "fo?")) .deep.equal([ "foo", "foo bar baz quux" ])
expect(sieve(items, "/fo./")).deep.equal([ "foo", "foo bar baz quux" ])
expect(sieve(items, "'foo'")).deep.equal([ "foo" ])
expect(sieve(items, "bax", { fuzzy: true })).deep.equal([ "bar", "baz" ])
expect(sieve(items, "fox", { fuzzy: true })).deep.equal([ "foo" ])
expect(sieve(items, "qxux", { fuzzy: true })).deep.equal([ "quux" ])
expect(sieve(items, "foo")) .deep.equal([ "foo", "foo bar baz quux" ])
expect(sieve(items, "foo bar")) .deep.equal([ "foo bar baz quux" ])
expect(sieve(items, "foo +bar")) .deep.equal([ "foo", "foo bar baz quux", "bar" ])
expect(sieve(items, "foo +bar -baz")).deep.equal([ "foo", "bar" ])
expect(sieve(items, "foo, bar")) .deep.equal([ "foo", "foo bar baz quux", "bar" ])
expect(sieve(items, "bar, foo")) .deep.equal([ "bar", "foo bar baz quux", "foo" ])The following is a symbolic grammar describing the supported query syntax. For more subtle details, see the actual PEG grammar of the underlying parser.
queries ::= query ("," query)* // union of queries
query ::= term (" " term)* // intersection of terms
term ::= operation? namespace? text boost? // single query term
operation ::= "+" | "-" // force union or subtraction of term
namespace ::= symbol | id ":" // match against a particular namespace
text ::= quoted | regexp | glob | bareword // four variants of the term
boost ::= "^" number? // optionally boost the results
quoted ::= /"(\\"|[^"])*"/ | /'(\\'|[^'])*'/ // double- or single-quoted term
regexp ::= /\/(\\\/|[^\/])*\// // regular expression term
glob ::= /.*[*?[\]{}].*/ // glob-style term
bareword ::= /.+/ // bareword term
number ::= /\d*\.\d+/ | /\d+/ // floating or integer number
symbol ::= /^[$#%@&]$/ // namespace symbol
id ::= /^[a-zA-Z][a-zA-Z0-9-_]*$/ // namespace identifier
The following is the API as a TypeScript declaration. See also the actual TypeScript definition file.
declare module "Sieving" {
class Sieving {
/* create Sieving instance */
public constructor(
options?: {
fieldsVal: string[], /* names of fields in items of type object (default: [ "value" ]) */
fieldId: string /* name of optional field of unique identifier in items of type object (default: "id") */
}
)
/* parse query into an internal AST */
parse(
query: string, /* query string */
options?: {
lts: boolean, /* parse query string into LST (default: true) */
ast: boolean /* parse query string into AST (default: true) */
}
): void
/* dump internal AST as text (for debugging purposes only) */
dump(
colorize?: boolean /* whether to colorize output (default: true) */
): string
/* format internal AST into query string */
format(
format: string /* format of output (default "text", or "html", "xml" or "json") */
): string
/* evaluate internal AST (for custom matching) */
evaluate(
queryResults: (
ns: string, /* term namespace (default: "") */
type: string, /* term type ("regexp", "glob", "squoted", "dquoted", or "bareword") */
value: string /* term value */
) => any[]
): any[]
/* sieve items by evaluating query with standard matching */
sieve(
items: any[], /* list of items to sieve/filter */
options?: {
fuzzy: boolean, /* whether to fuzzy match quoted and bare terms (default: false) */
nocase: boolean, /* whether to match case-insensitive (default: false) */
maxLS: number, /* maximum Levenshtein distance for fuzzy matching (default: 2) */
minDC: number /* minimum Dice-Coefficient for fuzzy matching (default: 0.50) */
}
): any[]
/* sieve items by evaluating query with standard matching (stand-alone) */
static sieve(
items: any[], /* list of items to sieve/filter */
query: string, /* query string */
options?: {
fieldsVal: string[], /* names of fields in items of type object (default: [ "value" ]) */
fieldId: string /* name of optional field of unique identifier in items of type object (default: "id") */
fuzzy: boolean, /* whether to fuzzy match quoted and bare terms (default: false) */
nocase: boolean, /* whether to match case-insensitive (default: false) */
maxLS: number, /* maximum Levenshtein distance for fuzzy matching (default: 2) */
minDC: number /* minimum Dice-Coefficient for fuzzy matching (default: 0.50) */
debug: boolean /* whether to dump the internal AST to stdout */
}
): any[]
}
export = Sieving
}Copyright © 2018-2024 Dr. Ralf S. Engelschall (http://engelschall.com/)
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