When
Generated from the engine's own definition: compute-engine's symbol, which we neither extend nor document by hand. No examples yet — the crosswalk is the reason it has a page.
Conditional/restriction value. `When(e, cond)` evaluates to: - `e` when `cond` evaluates to `True` - `Missing` when `cond` evaluates to `False` (the "masking rule": the position-preserving absent datum, the same answer a selection with no selected branch gives; consumers like 2D plotters skip masked points) - `When(e, cond_simplified)` when `cond` is indeterminate (holds) Stacked restrictions canonicalize: `When(When(e, c1), c2)` → `When(e, And(c1, c2))`. Compiles to ternary `(cond) ? (e) : NaN` in JS and GLSL.
When(expression, boolean) -> anyas compute-engine declares it