Module builtins 

Evaluation of the scalar built-in functions in [improv_core_model::functions::all]: one value per argument in, one value out. The dataflow maps this over aligned cells and the scalar evaluator calls it directly, so both give bit-identical results.

Errors are values (CellValue::Err with an ERROR.TYPE code): an error argument propagates (the first one, by argument order) except into the functions that inspect errors (ISERROR, …); a numeric domain error is #NUM! and a non-finite result is #NUM!. Positions are 1-based and count characters (Unicode scalar values), not bytes.

Modules

err

ERROR.TYPE codes, as stored in CellValue::Err. 0 is Improv’s own generic error (#ERR).

Functions

eval

Evaluate built-in func on args (already checked against the registry’s arity and types). An unknown id is #NAME?.