Add a shorthand/literal syntax for creating Maps

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Add a shorthand/literal syntax for creating Maps [12536532]

Submitted by Brad Collins on 3/1/2016 12:00:00 AM
[ 3 votes ]

A shorthand/literal syntax or computation expression for building Maps would be nice—something like the following: let m = map ["a",97; "b",98; "c",99] The shorthand for dictionaries ... let d = dict ["a",97; "b",98; "c",99] ... is nice, but while Maps implement IDictionary, dictionaries do not play well with Map module functions. One must inevitably convert a dictionary to a Map or create a Map with Map.ofArray, .ofList, or .ofSeq.

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Posted by amazingant on 3/7/2016 6:15:00 AM

You can add this yourself fairly easily by adding the following anywhere in your code: let map = Map.ofList and then your first code sample works

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Posted by Brad Collins on 3/7/2016 9:08:00 AM

@amazingant, no argument that it's an easy fix, but its seems like an obvious oversight (and perhaps even that's too strong a word) when we have shorthand for every other built-in F# container: lists, sequences, arrays, and sets. As someone who came to the language just a little over a year ago, I found it incongruous for map shorthand to be missing.

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Posted by AK on 3/10/2016 3:41:00 PM

You can already do this i.e Map [("Key", "Value); ("Key2", "Value2")] works fine in my code. Notice the capital M on Map

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Posted by Brad Collins on 3/10/2016 5:31:00 PM

@ak, ah, I see! I am embarrassed that I had not explored that option. But I see now that it's merely a call to the Map constructor. I will quibble that the style is inconsistent. That is, it's set [ ... ] for sets, dict [ ... ] for dictionaries, seq [ ... ] for sequences, but it's Map [ ... ] for maps. That inconsistency is not satisfying. Nevertheless, I concede the point that a shorthand clearly already exists. I just overlooked it.