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Effect KitRedis

Bitmaps

Look up the bit commands on strings, including bitfield operations and their reply types.

Bitmap commands treat a string as an array of bits. They live on strings, so the keys are ordinary string keys.

Example (Tracking Daily Activity)

import {  } from "effect";

import {  } from "@effect-kit/redis";

const  = .(function* () {
  const  = yield* ;

  const before = yield* .("active:2026-10-29", 42, 1);
         
const before: 0 | 1
  const active = yield* .("active:2026-10-29", 42);
         
const active: 0 | 1
  const total = yield* .("active:2026-10-29");
        
const total: bigint

  return { , ,  };
});

setbit returns the previous bit and getbit returns the bit, both typed as 0 | 1. Counts and positions are bigint.

Methods

MethodCommandReply typePurpose
redis.setbitSETBIT0 | 1Set the bit at an offset and return its previous value.
redis.getbitGETBIT0 | 1Read the bit at an offset.
redis.bitcountBITCOUNTbigintCount the set bits, optionally within a range.
redis.bitposBITPOSbigintFind the first bit set to 0 or 1.
redis.bitopBITOPbigintCombine bitmaps into a destination key.
redis.bitfieldBITFIELDreadonly Option<bigint>[]Read and write integer fields in a bitmap.
redis.bitfieldRoBITFIELD_ROreadonly bigint[]Read integer fields without writing.

Option types

  • BitRange for bitcount: { start: number | bigint; end: number | bigint; unit?: "BYTE" | "BIT" }.
  • BitPositionRange for bitpos: { start: number | bigint; end?: number | bigint; unit?: "BYTE" | "BIT" }.
  • BitOperation for bitop is "AND" | "OR" | "XOR" | "NOT" | "DIFF" | "DIFF1" | "ANDOR" | "ONE".
  • BitfieldRead is { operation: "GET"; encoding; offset }.
  • BitfieldOperation is a BitfieldRead or a write { operation: "SET" | "INCRBY"; encoding; offset; value; overflow?: "WRAP" | "SAT" | "FAIL" }.

encoding is { signed: true; bits: number } | { signed: false; bits: number }, and offset is a number or { index: number }.

On this page

MethodsOption types