@lutaml/ocl

OCL (Object Constraint Language) expression engine for TypeScript.

A standalone library extracted from the OIML SMART platform. Provides a subset of OCL suitable for embedded evaluation in measurement/validation workflows:

• Lexer with support for arithmetic, comparison, logical, and collection operators; [reference] syntax; $context variables; -> collection navigation; => and | lambda separators; ocl{ ... } prefix handling.
• Recursive-descent parser producing a typed AST.
• Evaluator that resolves references, context variables, lambdas, quantifiers, conditionals, and built-in functions (abs, round, floor, ceil, sqrt, pow, lookup, lookup_mpe, prev, ...).
• Static validator that surfaces unresolved identifiers, unknown functions, type mismatches, and circular dependencies without executing the expression.

Installation

npm install @lutaml/ocl

Usage

import { parseOcl, OclEvaluator, type EvaluationContext } from '@lutaml/ocl'

const ast = parseOcl('ocl{ [load] * 0.5 }')
const ctx: EvaluationContext = { measurements: { load: 100 } }
const result = new OclEvaluator(ctx).evaluate(ast)
// result === 50

License

BSD-3-Clause. See LICENSE.