Expressions

Where in the UI. Structure tab: expression library + expression graph canvas. Layout inspector can point a value source at an expression id.

An expression is a small program with no side effects. It has a graph (nodes and wires) that compiles to an AST stored on the template.

Tasks

1. Add an expression node on Structure; open the graph.
2. Put a fieldRef (e.g. amount) and a literal, then calculate.
3. Mark the output node. Use that expression id on a number widget or a field binding.

Palette groups

Inputs (fields, now, metrics, membership, context, variables). Logic (compare, boolean, if). Math. Time (between, split/merge). Units. Color (theme + adjust/split/merge). Advanced: computedRef.

Full node list: Expression nodes.