Std::HashMap

An open-addressing hash map from integer keys to pointer values.

Module: Std::HashMap

Struct

struct HashMap {
    data:  *uint8;
    cap:   uint;
    count: uint;
}

HashMap maps int keys to *opaque values. It uses open addressing with linear probing and grows automatically as it fills. Keys are 64-bit integers; values are opaque pointers, so you can store a pointer to any data you manage yourself.

A map must be initialized with Init (or InitWithCap) before use, and released with Free when done.

WARNING

The map stores pointers, not the pointed-to data. It never copies or frees what a value points to — managing that memory is the caller's responsibility. Keys are limited to int; there is no built-in string-keyed map.

Lifecycle

Function	Description
Init	Initialize a map (optionally with capacity).
Free	Release the map's memory.
Clear	Remove all entries, keep the allocation.

Entries

Method	Description
Set	Insert or update a key's value.
Get	Look up a value by key.
Contains	Test whether a key is present.
Remove	Delete a key.

Inspection

Method	Description
Len	Number of entries.
Cap	Number of slots currently allocated.
Keys	Allocate an array of all keys.
Values	Allocate an array of all values.

Example

import Std::HashMap::*;
import Std::Io::PrintLine;

func Main() -> int {
    var scores: HashMap;
    Init(&scores);

    scores.Set(1, &"Alice");
    scores.Set(2, &"Bob");

    if scores.Contains(1) {
        PrintLine("player 1 is registered");
    }
    PrintLine(scores.Len());         // 2

    scores.Free();
    return 0;
}