note description: "References to objects containing a real value" legal: "See notice at end of class." status: "See notice at end of class." date: "$Date$" revision: "$Revision$" class REAL_32_REF inherit NUMERIC redefine out, is_equal end COMPARABLE redefine out, three_way_comparison, is_equal end HASHABLE redefine is_hashable, out, is_equal end feature -- Access item: REAL -- Numeric real value hash_code: INTEGER -- Hash code value do Result := truncated_to_integer.hash_code end sign: INTEGER -- Sign value (0, -1 or 1) do if item > 0.0 then Result := 1 elseif item < 0.0 then Result := -1 end ensure three_way: Result = three_way_comparison (zero) end one: like Current -- Neutral element for "*" and "/" do create Result Result.set_item (1.0) end zero: like Current -- Neutral element for "+" and "-" do create Result Result.set_item (0.0) end feature -- Comparison infix "<" (other: like Current): BOOLEAN -- Is `other' greater than current real? do Result := item < other.item end is_equal (other: like Current): BOOLEAN -- Is `other' attached to an object of the same type -- as current object and identical to it? do Result := other.item = item end three_way_comparison (other: like Current): INTEGER -- If current object equal to `other', 0; -- if smaller, -1; if greater, 1 do if item < other.item then Result := -1 elseif other.item < item then Result := 1 end end feature -- Element change frozen set_item (r: REAL) -- Make `r' the value of `item'. do item := r end feature -- Status report divisible (other: like Current): BOOLEAN -- May current object be divided by `other'? do Result := other.item /= 0.0 ensure then ref_not_exact_zero: Result implies (other.item /= 0.0) end exponentiable (other: NUMERIC): BOOLEAN -- May current object be elevated to the power `other'? local integer_value: INTEGER_REF double_value: DOUBLE_REF real_value: REAL_REF do integer_value ?= other real_value ?= other double_value ?= other if integer_value /= Void then Result := integer_value.item >= 0 or item /= 0.0 elseif real_value /= Void then Result := real_value.item >= 0.0 or item /= 0.0 elseif double_value /= Void then Result := double_value.item >= 0.0 or item /= 0.0 end ensure then safe_values: ((other.conforms_to (0) and item /= 0.0) or (other.conforms_to (0.0) and item > 0.0)) implies Result end is_hashable: BOOLEAN -- May current object be hashed? -- (True if it is not its type's default.) do Result := item /= 0.0 end feature {NONE} -- Initialization make_from_reference (v: REAL_REF) -- Initialize `Current' with `v.item'. require v_not_void: v /= Void do item := v.item ensure item_set: item = v.item end feature -- Conversion to_reference: REAL_REF -- Associated reference of Current do create Result Result.set_item (item) ensure to_reference_not_void: Result /= Void end truncated_to_integer: INTEGER -- Integer part (same sign, largest absolute -- value no greater than current object's) do if item >= 0.0 then Result := {SYSTEM_CONVERT}.to_int_32_double ({MATH}.floor (item)) else Result := {SYSTEM_CONVERT}.to_int_32_double ({MATH}.ceiling (item)) end end truncated_to_integer_64: INTEGER_64 -- Integer part (same sign, largest absolute -- value no greater than current object's) do if item >= 0.0 then Result := {SYSTEM_CONVERT}.to_int_64_double ({MATH}.floor (item)) else Result := {SYSTEM_CONVERT}.to_int_64_double ({MATH}.ceiling (item)) end end to_double: DOUBLE -- Current seen as a double do Result := item.to_double end ceiling: INTEGER -- Smallest integral value no smaller than current object do Result := {SYSTEM_CONVERT}.to_int_32_double ({MATH}.ceiling (item)) ensure result_no_smaller: Result >= item close_enough: Result - item < item.one end floor: INTEGER -- Greatest integral value no greater than current object do Result := {SYSTEM_CONVERT}.to_int_32_double ({MATH}.floor (item)) ensure result_no_greater: Result <= item close_enough: item - Result < Result.one end rounded: INTEGER -- Rounded integral value do Result := sign * {SYSTEM_CONVERT}.to_int_32_double ({MATH}.floor ({MATH}.abs_real (item) + 0.5)) ensure definition: Result = sign * ((abs + 0.5).floor) end ceiling_real_32: REAL -- Smallest integral value no smaller than current object do Result := {MATH}.ceiling (item) ensure result_no_smaller: Result >= item close_enough: Result - item < item.one end floor_real_32: REAL -- Greatest integral value no greater than current object do Result := {MATH}.floor (item) ensure result_no_greater: Result <= item close_enough: item - Result < Result.one end rounded_real_32: REAL -- Rounded integral value do Result := sign * {MATH}.floor ({MATH}.abs_real (item) + 0.5) ensure definition: Result = sign * ((abs + 0.5).floor_real_32) end feature -- Basic operations abs: REAL -- Absolute value do Result := abs_ref.item ensure non_negative: Result >= 0.0 same_absolute_value: (Result = item) or (Result = -item) end infix "+" (other: like Current): like Current -- Sum with `other' do create Result Result.set_item (item + other.item) end infix "-" (other: like Current): like Current -- Result of subtracting `other' do create Result Result.set_item (item - other.item) end infix "*" (other: like Current): like Current -- Product by `other' do create Result Result.set_item (item * other.item) end infix "/" (other: like Current): like Current -- Division by `other' do create Result Result.set_item (item / other.item) end infix "^" (other: DOUBLE): DOUBLE -- Current real to the power `other' do Result := item ^ other end prefix "+": like Current -- Unary plus do create Result Result.set_item (+ item) end prefix "-": like Current -- Unary minus do create Result Result.set_item (- item) end feature -- Output out: STRING -- Printable representation of real value do create Result.make_from_cil ({SYSTEM_CONVERT}.to_string_real_iformat_provider (item, {CULTURE_INFO}.invariant_culture)) end feature {NONE} -- Implementation abs_ref: REAL_REF -- Absolute value do if item >= 0.0 then Result := Current else Result := -Current end ensure result_exists: Result /= Void same_absolute_value: equal (Result, Current) or equal (Result, - Current) end invariant sign_times_abs: sign * abs = item note library: "EiffelBase: Library of reusable components for Eiffel." copyright: "Copyright (c) 1984-2006, Eiffel Software and others" license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)" source: "[ Eiffel Software 356 Storke Road, Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end