---
id: LANG-6
family: GR-LANG
level: core
profiles: [runtime]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-lang/lang-6
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# LANG-6 — Expression-language evaluation fails loudly

*GR-LANG (Part I) · level: core · profiles: runtime · added in 1.0*

## The rule

> **Normative.** This is the rule.
>
> An expression-language expression that cannot be parsed, that cannot be evaluated, or that references a name absent from the context fails: it raises an error and yields no value.

## Related rules

- Names: LANG-7, LANG-8, LANG-9
- Referenced by: LANG-10

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.