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Stefan
f62eb9a8ed
Cell text listed range tokens first ("> 5, null"); the VM evaluates list items left to right and a comparison throws on non-numbers, so null/string/bool values never matched. Compression and missing-case fixes produced cells that changed results. Switch conditions on date fields now narrow date columns by date instead of by string.
ZEN Expression Language
The expression language of ZEN Engine, the open-source Business Rules Engine (BRE) from GoRules.
ZEN expressions are readable by business users and fast enough for hot paths: a complete language for conditions, calculations and data transformation, with lexer, parser, compiler, VM, type checking and editor completions included in this crate.
use serde_json::json;
use zen_expression::evaluate_expression;
fn main() {
let result = evaluate_expression(
"sum(items) * multiplier",
json!({ "items": [10, 20, 30], "multiplier": 2 }).into(),
)
.unwrap();
// => 120
}
Reusable expressions compile once via compile_expression and evaluate repeatedly against different contexts.
Resources
- ZEN Expression Language reference - syntax, operators, built-in functions and date operations
- ZEN Engine - the rules engine built on this language
- GoRules - the platform around the open-source engine
- Online Editor - try expressions in the free editor with a built-in simulator