A <foreach> executable-content element (spec 4.6): iterates over an array, binding item (and, optionally, index) in the datamodel for each element, then running its own child content once per iteration.

4.6.2's attribute table:

array (Executable Content Attribute, Compiled Value expressions) require="true". The expression evaluates to a legal iterable collection.

item require="true". The name of the variable that holds the current item of the array. Any errors in evaluating this expression, or, more generally, any errors on entering the <foreach> element MUST cause processing within this element to cease.

index require="false". The name of a variable that holds the current index. If unspecified, no index variable is used.

4.6.3 treats the whole <foreach> body as a single unit:

if the SCXML processor encounters an error while evaluating [the <foreach> element's contents], it must ... treat these actions as part of the same block of executable content as the parent <foreach> element.

Unlike Statifier.Document.If, <foreach> has no partitioning: content is the flat [Document.content_node()] list <foreach>'s children lower into, in document order - never a branch struct, since there is exactly one child block and the array/ item/index attributes all belong to <foreach> itself rather than to any partition of it.

array and item are the raw, uncompiled attribute strings (this layer never references Predicator - Statifier.Document's moduledoc); item legality (a bare variable name, not a system variable) is a runtime check, not a lowering or validator one (Decision 1 of the plan above). index is nil when the author wrote none. location is the <foreach> element's own span - as with %Document.If{}, and unlike %Document.Assign{}, there is no name collision between an attribute and the element's own span here, so no node_location rename is needed.