1
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var baseRest = require('./_baseRest'),
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2
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createWrap = require('./_createWrap'),
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3
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getHolder = require('./_getHolder'),
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4
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replaceHolders = require('./_replaceHolders');
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5
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6
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/** Used to compose bitmasks for function metadata. */
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7
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var WRAP_BIND_FLAG = 1,
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8
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WRAP_BIND_KEY_FLAG = 2,
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9
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WRAP_PARTIAL_FLAG = 32;
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10
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11
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/**
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* Creates a function that invokes the method at `object[key]` with `partials`
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13
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* prepended to the arguments it receives.
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14
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*
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* This method differs from `_.bind` by allowing bound functions to reference
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16
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* methods that may be redefined or don't yet exist. See
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17
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* [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern)
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18
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* for more details.
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19
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*
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20
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* The `_.bindKey.placeholder` value, which defaults to `_` in monolithic
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21
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* builds, may be used as a placeholder for partially applied arguments.
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22
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*
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23
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* @static
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24
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* @memberOf _
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25
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* @since 0.10.0
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26
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* @category Function
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* @param {Object} object The object to invoke the method on.
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28
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* @param {string} key The key of the method.
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29
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* @param {...*} [partials] The arguments to be partially applied.
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* @returns {Function} Returns the new bound function.
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31
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* @example
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32
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*
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33
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* var object = {
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34
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* 'user': 'fred',
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35
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* 'greet': function(greeting, punctuation) {
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36
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* return greeting + ' ' + this.user + punctuation;
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37
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* }
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* };
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39
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*
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* var bound = _.bindKey(object, 'greet', 'hi');
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41
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* bound('!');
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* // => 'hi fred!'
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43
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*
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* object.greet = function(greeting, punctuation) {
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45
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* return greeting + 'ya ' + this.user + punctuation;
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46
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* };
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47
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*
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48
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* bound('!');
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49
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* // => 'hiya fred!'
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50
|
*
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51
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* // Bound with placeholders.
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52
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* var bound = _.bindKey(object, 'greet', _, '!');
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53
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* bound('hi');
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54
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* // => 'hiya fred!'
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55
|
*/
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56
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var bindKey = baseRest(function(object, key, partials) {
|
57
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var bitmask = WRAP_BIND_FLAG | WRAP_BIND_KEY_FLAG;
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58
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if (partials.length) {
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59
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var holders = replaceHolders(partials, getHolder(bindKey));
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60
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bitmask |= WRAP_PARTIAL_FLAG;
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61
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}
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62
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return createWrap(key, bitmask, object, partials, holders);
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63
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});
|
64
|
|
65
|
// Assign default placeholders.
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66
|
bindKey.placeholder = {};
|
67
|
|
68
|
module.exports = bindKey;
|