docs: refresh Map tutorial #2045
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| let int_map : int StringMap.t = StringMap.empty;; | ||
| let float_map : float StringMap.t = StringMap.empty;; |
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In these code examples for the toplevel, we've been starting them with a # and putting the expected result in the last line. Shall I go through and do that?
| - : unit = () | ||
| The behavior of `StringMap.union` can be tuned based on the conflict function we pass in. | ||
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| For example, we can always pick the value from the first map, or choose to sum both values together (which would only work for values of type `int`), or we can even choose to ignore a value entirely if it is present in both maps. |
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Since there are three choices, which makes for a long, slightly confusing sentence, what do you think of making these a bullet list?
| - : int = 42 | ||
| ### Filtering a Map | ||
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| To filter a map, we can use the `filter` function. `filter` takes a predicate to filter entries by and a map. It returns a new map with only the entries that passed the filter. |
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| To filter a map, we can use the `filter` function. `filter` takes a predicate to filter entries by and a map. It returns a new map with only the entries that passed the filter. | |
| To filter a map, we can use the `filter` function. `filter` filters entries by taking a predicate and a map. It returns a new map with only the entries that passed the filter. |
Does this make things more clear or is it now incorrect?
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| ``` | ||
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| Note that our module has a `type t` and also a `compare` function. Now we can call the **Map.Make** function on it, to get a map for non-negative numbers: |
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| Note that our module has a `type t` and also a `compare` function. Now we can call the **Map.Make** function on it, to get a map for non-negative numbers: | |
| Note that our module has a `type t` and also a `compare` function. Now we can call the **Map.Make** function to get a map for non-negative numbers: |
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Also, checks are failing because the formatting was broken upstream. Please rebase. |
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do you by any chance have that as a branch somewhere? |
It's there: |
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I have two more commits there: https://github.com/ocaml/ocaml.org/tree/doc-maps |
| # let lucky_numbers = StringMap.of_list [ | ||
| ("leostera", 2112); | ||
| ("charstring88", 88); | ||
| ("divagnz", 13); | ||
| ];; | ||
| val lucky_numbers : int StringMap.t = <abstr> |
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I get Error: Unbound value StringMap.of_list here
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That's an OCaml version issue. of_list was added in OCaml 5.1. We can have this to make compatible with 4.14
let lucky_numbers = StringMap.of_seq @@ List.to_seq [
BTW. Should it be a requirement for all tutorials? Be compatible with 4.14 ? Since it is LTS it probably make sense.
We can have 5.x related stuff as remarks/notes
Hello folks! Here's a refresh on the Map tutorial. I followed the style of the new Set tutorial to make the structure easy to recognize.
As always, happy to change anything :)