hash

The hash module provides common hash functions implemented in pure Conjure. These are useful for hash tables, checksums, and data integrity checks.

import "conjure/hash"

#String Hashing

#hashString

Computes a 32-bit FNV-1a hash of a string. This is the primary hash function and should be used for most hashing needs.

var h = hash.hashString("hello")
io.println("Hash: #{h}")

Signature:

func hashString(s string) u32

The FNV-1a algorithm provides good distribution and is fast for typical string lengths.

#hashString64

Computes a 64-bit FNV-1a hash of a string. Use this when you need better distribution for larger hash tables or when collisions are particularly costly.

var h = hash.hashString64("hello world")

Signature:

func hashString64(s string) u64

#Combining Hashes

#combineHashes

Combines two 32-bit hash values into one. Useful for hashing composite data structures where you need to combine hashes of multiple fields.

struct Point {
    x i32
    y i32
}

func hashPoint(p Point) u32 {
    var hx = hash.hashString("#{p.x}")
    var hy = hash.hashString("#{p.y}")
    return hash.combineHashes(hx, hy)
}

Signature:

func combineHashes(h1 u32, h2 u32) u32

#combineHashes64

Combines two 64-bit hash values into one.

var h1 = hash.hashString64("key")
var h2 = hash.hashString64("value")
var combined = hash.combineHashes64(h1, h2)

Signature:

func combineHashes64(h1 u64, h2 u64) u64

#Example: Simple Hash Map Bucket

import "conjure/hash"

const BUCKET_COUNT = 256

func getBucket(key string) u32 {
    return hash.hashString(key) % BUCKET_COUNT
}

#Example: Hashing a Struct

import "conjure/hash"

struct User {
    id i32
    name string
    email string
}

func hashUser(u User) u32 {
    var h1 = hash.hashString("#{u.id}")
    var h2 = hash.hashString(u.name)
    var h3 = hash.hashString(u.email)

    var combined = hash.combineHashes(h1, h2)
    return hash.combineHashes(combined, h3)
}

#Hash Quality

The FNV-1a algorithm used by this module provides:

• Good distribution for typical inputs
• Fast computation
• Low collision rates for hash tables

For cryptographic purposes (password hashing, digital signatures), use a cryptographic hash function instead. The hashes in this module are designed for speed and distribution, not security.