docs/Writerside/topics/map.h.md

Thu, 23 Jan 2025 01:33:36 +0100

author
Mike Becker <universe@uap-core.de>
date
Thu, 23 Jan 2025 01:33:36 +0100
branch
docs/3.1
changeset 1141
a06a2d27c043
child 1142
9437530176bc
permissions
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create new page structure

relates to #451

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1 # map.h
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2
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3 Similar to the list interface, the map interface provides a common API for implementing maps.
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4 There are some minor subtle differences, though.
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5
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6 First, the `remove` method is not always a destructive removal.
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7 Instead, the last argument is a Boolean that indicates whether the element shall be destroyed or returned.
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8 ```c
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9 void *(*remove)(CxMap *map, CxHashKey key, bool destroy);
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10 ```
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11 When you implement this method, you are either supposed to invoke the destructors and return `NULL`,
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12 or just remove the element from the map and return it.
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13
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14 Secondly, the iterator method is a bit more complete. The signature is as follows:
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15 ```c
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16 CxIterator (*iterator)(const CxMap *map, enum cx_map_iterator_type type);
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17 ```
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18 There are three map iterator types: for values, for keys, for pairs.
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19 Depending on the iterator type requested, you need to create an iterator with the correct methods that
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20 return the requested thing.
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21 There are no automatic checks to enforce this - it's completely up to you.
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22 If you need inspiration on how to do that, check the hash map implementation that comes with UCX.

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