Turns merge fields into statements.
A handler claims a field by matching its expression and then builds the
matching statement, consuming further fields from the construction state
when the statement spans a block. Custom handlers are registered with
Sablon.Processor.Document.register_field_handler/2.
Summary
Callbacks
@callback build_statement( Sablon.Processor.Document.OperationConstruction.t(), term(), keyword() ) :: {struct() | nil, Sablon.Processor.Document.OperationConstruction.t()}
Builds a statement for field.
Returns the statement (or nil when the field produces none) together with
the updated construction state.
Whether this handler can process field.