comphash is a very lightweight Zig package offering a compile-time hash map for immutable, O(1) string-keyed lookups.

Perfect for command‑line flag tables, protocol constant look‑ups, compile‑time DSLs, and any situation where the set of keys is known ahead of time.

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✨ Features

Category	Details
Lookup	O(1) expected access.
Hash Algorithms	Use any fn([]const u8) u64 — the default is xxHash64 from zighash.
Probing	Prober enum: Linear, DoubleHash, Bidirectional, Triangular.
Iterators	Type‑driven keys(), values(), items()—all lazy and allocation‑free.

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🚀 Getting Started

Fetch via zig fetch

zig fetch --save git+https://github.com/galactixx/comphash#v0.3.0

This adds a comphash entry under .dependencies in your build.zig.zon.

Then in your build.zig:

const comphash_mod = b.dependency("comphash", .{
    .target = target,
    .optimize = optimize,
}).module("comphash");

// add to library
lib_mod.addImport("comphash", comphash_mod);

// add to executable
exe.root_module.addImport("comphash", comphash_mod);

This lets you const ch = @import("comphash"); in your Zig code.

📚 Usage

const std = @import("std");
const ch = @import("comphash");

const FruitMap = ch.ComptimeHashMap(u32, null, null, null);

pub fn main() !void {
    const kv = &.{ .{ "apple", 10 }, .{ "banana", 20 }, .{ "cherry", 30 } };
    const map = FruitMap.init(kv);

    std.debug.print("apple → {}\n", .{map.get("apple") orelse 0});
    std.debug.print("Length: {}\n",  .{map.length()});
}

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🔍 API

ComptimeHashMap

pub fn ComptimeHashMap(
    comptime V:      type,                          // value type
    comptime hasher: ?fn([]const u8) u64,           // optional hash func
    comptime prober: ?Prober,                       // optional probe strategy
    comptime eql:    ?fn([]const u8,[]const u8)bool // optional equality
) type

Calling this generic returns a new struct type with the following methods:

Method	Description
init(kvs)	Build the table at comptime. Accepts []const struct { []const u8, V }.
get(key)	Returns ?V.
contains(key)	Boolean containment check.
length() / isEmpty()	Item count helpers.
keys() / values() / items()	Lazy iterators.
capacity()	Underlying table size (power‑of‑two).

Prober

An enum that provides options for probing:

• Linear – base + i
• DoubleHash – base + i * (h(key) | 1)
• Bidirectional – Alternates ±offsets
• Triangular – base + i * (i + 1) / 2

Select with the third parameter to ComptimeHashMap.

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🤝 License

This project is licensed under the MIT License. See the LICENSE file for details.

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📞 Contact & Contributing

Feel free to open an issue or a pull request. Discussion and feedback are welcome!