note description: "[ Objects representing delayed calls to a function, with some arguments possibly still open. Notes: Features are the same as those of ROUTINE, with `apply' made effective, and the addition of `last_result' and `item'. ]" legal: "See notice at end of class." status: "See notice at end of class." date: "$Date$" revision: "$Revision$" class FUNCTION [OPEN_ARGS -> detachable TUPLE create default_create end, RESULT_TYPE] inherit ROUTINE [OPEN_ARGS] redefine is_equal, copy end create {NONE} set_rout_disp, set_rout_disp_final feature -- Access last_result: detachable RESULT_TYPE -- Result of last call, if any. item alias "()" (args: detachable OPEN_ARGS): RESULT_TYPE -- Result of calling function with `args' as operands. require valid_operands: valid_operands (args) callable: callable do set_operands (args) clear_last_result -- If result is attached, it is of type {RESULT_TYPE}. if attached {RESULT_TYPE} rout_disp.invoke (target_object, internal_operands) as r then Result := r else -- Result is `Void'. -- The type {RESULT_TYPE} has to be detachable. check ({RESULT_TYPE}).has_default end Result := ({RESULT_TYPE}).default end if is_cleanup_needed then remove_gc_reference end end feature -- Comparison is_equal (other: like Current): BOOLEAN -- Is associated function the same as the one -- associated with `other'? do Result := Precursor (other) and then equal (last_result, other.last_result) end feature -- Duplication copy (other: like Current) -- Use same function as `other'. do Precursor (other) last_result := other.last_result end feature -- Basic operations apply -- Call function with `operands' as last set. do if attached {RESULT_TYPE} rout_disp.invoke (target_object, internal_operands) as r then last_result := r else clear_last_result end end feature -- Obsolete eval (args: detachable OPEN_ARGS): RESULT_TYPE -- Result of evaluating function for `args'. obsolete "Please use `item' instead. [2017-05-31]" require valid_operands: valid_operands (args) callable: callable do Result := item (args) end feature -- Removal clear_last_result -- Reset content of `last_result' to its default value local l_result: detachable RESULT_TYPE do last_result := l_result end feature -- Extended operations flexible_item (a: detachable separate TUPLE): RESULT_TYPE -- Result of calling function with `a' as arguments. -- Compared to `item' the type of `a' may be different from `{OPEN_ARGS}'. require valid_operands: valid_operands (a) local default_arguments: detachable OPEN_ARGS do if not attached a then Result := item (default_arguments) else check from_precondition: attached {OPEN_ARGS} new_tuple_from_tuple (({OPEN_ARGS}).type_id, a) as x then Result := item (x) end end end note library: "EiffelBase: Library of reusable components for Eiffel." copyright: "Copyright (c) 1984-2017, Eiffel Software and others" license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)" source: "[ Eiffel Software 5949 Hollister Ave., Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end