The expression evaluator is introduced the infix binary operators set via an
array of pointers to
struct x1f4_operator_type records, of which the
last is null.
See struct x1f4_operator_type.
Setting up the expression parser becomes:
struct x1f4_attributes_type attributes; ... attributes.operator2s = <operator definition pointers array>; ... status = x1f4_init_expression(..., ..., ..., &attributes);
See struct x1f4_attributes_type.
Operator definitions may be used up to parsed expression destruction, thus the infix binary operator definition references and the array listing them must be valid for as long as the result of expression parsing is used.