# ezylang/EvalEx

EvalEx is a handy expression evaluator for Java, that allows to evaluate simple mathematical and boolean expressions.

Repository: https://github.com/ezylang/EvalEx
Canonical: https://ross.abutalabs.com/products/evalex
Homepage: https://ezylang.github.io/EvalEx/
Language: Java
License: Apache-2.0
License Family: permissive
Topics: expression-evaluator, expression-parser, java
Last push: 2026-08-13T12:16:05+00:00

## Health v2 (maintenance only)
Score: 87/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 97, release rhythm 68, longevity 100
- inputs: {"age_days": 5009, "days_push": 20, "days_rel": 54, "gap_med": 111, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1115, forks 291 (observed 2026-08-28T04:03:38.397612+00:00)

## What it is
EvalEx is a Java library for parsing and evaluating mathematical, boolean, string, date-time, array, and structure expressions. It uses BigDecimal for precise arithmetic, supports custom functions and operators, and has no external dependencies.

## Use cases
- evaluate user-entered math formulas in a Java app
- parse and evaluate boolean expressions at runtime
- compute expressions with BigDecimal precision
- allow users to define custom formulas with variables
- evaluate expressions over JSON-like arrays and structures
- add a safe expression engine to a rules engine or calculator

## When to choose
- you need a lightweight, dependency-free expression evaluator on the JVM
- you need arbitrary-precision decimal math with configurable rounding
- you want extensible custom functions and operators
- you need string, date-time, array, and structure support in expressions

## When to avoid
- you need a full scripting language rather than expression evaluation
- your project requires Java below version 11
- you need extremely high-performance bulk evaluation of millions of expressions

## Facets
- artifact type: library
- maturity: stable
- function: parser, interpreter, math
- domain: developer-tools, programming-languages
- platform: jvm
- tags: expression-evaluator, expression-parser, bigdecimal, no-dependencies, formula-evaluation, algorithms

## Member repositories
- ezylang/EvalEx (main) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:38.397612+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:42:10.669185+00:00, confidence not recorded.
  - readme: https://github.com/ezylang/EvalEx (fetched 2026-08-28T04:03:38.397612+00:00, sha 29a4003eacac)
  - homepage: https://ezylang.github.io/EvalEx/ (fetched 2026-08-29T12:45:55.758903+00:00, sha d20027bef4d1)
- Data as of 2026-08-30T08:39:29.467469+00:00.