IfcQuantity* carries an optional Formula (IfcLabel) documenting how a
quantity was derived. Export it alongside each quantity so it survives
in the Quantities column.
The per-quantity entry shape grows from [name, value] to
[name, value, formula], which stays backward compatible for positional
consumers reading index 0/1. Formula is read with a schema-safe getattr
(it does not exist on IfcPhysicalComplexQuantity, nor in IFC2X3) and is
coalesced to "" when absent.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
serialise_cost_quantities built the "Quantities" JSON string by manual
concatenation, inserting quantity.Name and the related element's Name
without any escaping. A name containing a double quote, backslash or
newline produced invalid JSON, breaking any downstream parser (e.g. a
Typst json.decode consumer reporting "failed to parse JSON"). It also
crashed with a TypeError when a name was None (str += None).
Build a Python list and serialise it with json.dumps instead, keeping
the exact same [[name, value], ...] output shape, the element-name
prefix and the unsupported-type behaviour. None names are coalesced to
"" and quantity values are defensively coerced to float.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
carlopav