website/themes/hugo-theme-wave/static/bower_components/lunr.js/lib/pipeline.js
2020-01-12 23:32:32 +01:00

231 lines
6.3 KiB
JavaScript

/*!
* lunr.Pipeline
* Copyright (C) @YEAR Oliver Nightingale
*/
/**
* lunr.Pipelines maintain an ordered list of functions to be applied to all
* tokens in documents entering the search index and queries being ran against
* the index.
*
* An instance of lunr.Index created with the lunr shortcut will contain a
* pipeline with a stop word filter and an English language stemmer. Extra
* functions can be added before or after either of these functions or these
* default functions can be removed.
*
* When run the pipeline will call each function in turn, passing a token, the
* index of that token in the original list of all tokens and finally a list of
* all the original tokens.
*
* The output of functions in the pipeline will be passed to the next function
* in the pipeline. To exclude a token from entering the index the function
* should return undefined, the rest of the pipeline will not be called with
* this token.
*
* For serialisation of pipelines to work, all functions used in an instance of
* a pipeline should be registered with lunr.Pipeline. Registered functions can
* then be loaded. If trying to load a serialised pipeline that uses functions
* that are not registered an error will be thrown.
*
* If not planning on serialising the pipeline then registering pipeline functions
* is not necessary.
*
* @constructor
*/
lunr.Pipeline = function () {
this._stack = []
}
lunr.Pipeline.registeredFunctions = {}
/**
* Register a function with the pipeline.
*
* Functions that are used in the pipeline should be registered if the pipeline
* needs to be serialised, or a serialised pipeline needs to be loaded.
*
* Registering a function does not add it to a pipeline, functions must still be
* added to instances of the pipeline for them to be used when running a pipeline.
*
* @param {Function} fn The function to check for.
* @param {String} label The label to register this function with
* @memberOf Pipeline
*/
lunr.Pipeline.registerFunction = function (fn, label) {
if (label in this.registeredFunctions) {
lunr.utils.warn('Overwriting existing registered function: ' + label)
}
fn.label = label
lunr.Pipeline.registeredFunctions[fn.label] = fn
}
/**
* Warns if the function is not registered as a Pipeline function.
*
* @param {Function} fn The function to check for.
* @private
* @memberOf Pipeline
*/
lunr.Pipeline.warnIfFunctionNotRegistered = function (fn) {
var isRegistered = fn.label && (fn.label in this.registeredFunctions)
if (!isRegistered) {
lunr.utils.warn('Function is not registered with pipeline. This may cause problems when serialising the index.\n', fn)
}
}
/**
* Loads a previously serialised pipeline.
*
* All functions to be loaded must already be registered with lunr.Pipeline.
* If any function from the serialised data has not been registered then an
* error will be thrown.
*
* @param {Object} serialised The serialised pipeline to load.
* @returns {lunr.Pipeline}
* @memberOf Pipeline
*/
lunr.Pipeline.load = function (serialised) {
var pipeline = new lunr.Pipeline
serialised.forEach(function (fnName) {
var fn = lunr.Pipeline.registeredFunctions[fnName]
if (fn) {
pipeline.add(fn)
} else {
throw new Error('Cannot load un-registered function: ' + fnName)
}
})
return pipeline
}
/**
* Adds new functions to the end of the pipeline.
*
* Logs a warning if the function has not been registered.
*
* @param {Function} functions Any number of functions to add to the pipeline.
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.add = function () {
var fns = Array.prototype.slice.call(arguments)
fns.forEach(function (fn) {
lunr.Pipeline.warnIfFunctionNotRegistered(fn)
this._stack.push(fn)
}, this)
}
/**
* Adds a single function after a function that already exists in the
* pipeline.
*
* Logs a warning if the function has not been registered.
*
* @param {Function} existingFn A function that already exists in the pipeline.
* @param {Function} newFn The new function to add to the pipeline.
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.after = function (existingFn, newFn) {
lunr.Pipeline.warnIfFunctionNotRegistered(newFn)
var pos = this._stack.indexOf(existingFn)
if (pos == -1) {
throw new Error('Cannot find existingFn')
}
pos = pos + 1
this._stack.splice(pos, 0, newFn)
}
/**
* Adds a single function before a function that already exists in the
* pipeline.
*
* Logs a warning if the function has not been registered.
*
* @param {Function} existingFn A function that already exists in the pipeline.
* @param {Function} newFn The new function to add to the pipeline.
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.before = function (existingFn, newFn) {
lunr.Pipeline.warnIfFunctionNotRegistered(newFn)
var pos = this._stack.indexOf(existingFn)
if (pos == -1) {
throw new Error('Cannot find existingFn')
}
this._stack.splice(pos, 0, newFn)
}
/**
* Removes a function from the pipeline.
*
* @param {Function} fn The function to remove from the pipeline.
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.remove = function (fn) {
var pos = this._stack.indexOf(fn)
if (pos == -1) {
return
}
this._stack.splice(pos, 1)
}
/**
* Runs the current list of functions that make up the pipeline against the
* passed tokens.
*
* @param {Array} tokens The tokens to run through the pipeline.
* @returns {Array}
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.run = function (tokens) {
var out = [],
tokenLength = tokens.length,
stackLength = this._stack.length
for (var i = 0; i < tokenLength; i++) {
var token = tokens[i]
for (var j = 0; j < stackLength; j++) {
token = this._stack[j](token, i, tokens)
if (token === void 0 || token === '') break
};
if (token !== void 0 && token !== '') out.push(token)
};
return out
}
/**
* Resets the pipeline by removing any existing processors.
*
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.reset = function () {
this._stack = []
}
/**
* Returns a representation of the pipeline ready for serialisation.
*
* Logs a warning if the function has not been registered.
*
* @returns {Array}
* @memberOf Pipeline
*/
lunr.Pipeline.prototype.toJSON = function () {
return this._stack.map(function (fn) {
lunr.Pipeline.warnIfFunctionNotRegistered(fn)
return fn.label
})
}