51 lines
1.5 KiB
Text
51 lines
1.5 KiB
Text
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title:: Key Value Pairs
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summary:: An interface for translating between three common data structures: Dictionaries, Arrays of Associations and of Pairs
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categories:: Collections, Interfaces
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related::Classes/IdentityDictionary, Classes/Array, Classes/Association
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SECTION::Motivation
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There are three very similar ways to represent maps between keys and values, each of which have a specific purpose:
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TABLE::
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## key value pairs || common representation of arguments || code::[\freq, 452, \amp, 0.2]::
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## collections of associations || ordering, array and collection methods || code::[0 -> [1, 2, 3], 1 -> [2, 1]]::
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## dictionaries: fast lookup || event compatibility || code::(instrument: \sine, freq: 561)::
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::
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To make it easy to translate between these purposes and representations, there is a uniform set of methods:
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TABLE::
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##code::asPairs:: || returns an array of key value pairs
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##code::asAssociations:: || returns an array of associations
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##code::asDict:: || returns an IdentityDictionary
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::
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EXAMPLES::
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CODE::
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// the following all return [\freq, 452, \amp, 0.2]
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[\freq, 452, \amp, 0.2].asPairs
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[\freq -> 452, \amp -> 0.2].asPairs
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(freq: 452, amp: 0.2).asPairs
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// the following all return [\freq -> 452, \amp -> 0.2]
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[\freq, 452, \amp, 0.2].asAssociations
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[\freq -> 452, \amp -> 0.2].asAssociations
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(freq: 452, amp: 0.2).asAssociations
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// the following all return (freq: 452, amp: 0.2) or the equivalent IdentityDictionary
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[\freq, 452, \amp, 0.2].asDict
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[\freq -> 452, \amp -> 0.2].asDict
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(freq: 452, amp: 0.2).asDict
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::
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