metosin/malli

Full support for decimal

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#1272 opened on Apr 1, 2026

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 (1 comment) (0 reactions) (0 assignees)Clojure (1,724 stars) (237 forks)batch import
enhancementhelp wanted

Description

Hello :) Found myself having to make some stylistic compromises with decimals in my schema, and would have liked it if it was supported like a :double schema with min max preds and bound generation.

Alternatives:

  • use decimal? and custom generators / and :and for bounds
  • define my own schema

Thanks

Contributor guide

Tech stack
None
Domain
backend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
familiarity with malli schema definitionsbasic Clojure
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The issue asks for full decimal support similar to :double. Start by examining the existing :double schema implementation, including its min, max, and bound generation. Look at the relevant source files (e.g., src/malli/impl/schema.clj) to understand the pattern. Then design a :decimal schema that supports similar features. Consider the comment in the issue for additional context.