The expression language
The rules that are not a per-entry fact — the value model, the number model, the JSON ingestion contract, the failure contract, the type-discipline rules, the regular-expression subset, the path grammar, operator precedence, the declared timezone, and this phase's known limitations — live on the eight subpages below, one rule area per page. Every per-entry fact — a function's signature, its description, its worked examples — lives on the generated Function & Operator Catalog page instead, because that page is generated from the registry and cannot drift from the code; restating a per-entry fact here would be a second copy of a fact that can drift, which is exactly how a specification starts lying.
Find an answer by question
Each row links to the subpage that answers the question, in an author's own words.
| Question | Page |
|---|---|
| What happens when a value is missing? | Values & Numbers |
| What happens when arithmetic cannot be performed? | When Expressions Fail |
| Why will the plus symbol not join two names? | Types & Conversions |
| What does the engine do with a number a connected system sends as text? | Reading Input Data |
| How does a path pick rows out of a list? | Paths & Filters |
| How is a text pattern matched safely? | Text Patterns |
| What does "today" mean? | Dates & Timezone |
| Which behaviours depend on the host platform? | Known Limitations |