Ada Programming/Keywords/use
< Ada Programming | Keywords
Use clause
At library level
This use clause make the content of a package immediately visible.
with
Ada.Text_IO;use
Ada.Text_IO;procedure
Hellois
begin
Put_Line("Hello, world!"); New_Line; Put_Line("I am an Ada program with package use.");end
Hello;
If readability is your main concern then you should avoid this type of use clause. However it is needed to resolve a name clash between the packages which are imported and the package currently compiled.
At declaration level
with
Ada.Text_IO;procedure
Hellois
use
Ada.Text_IO;begin
Put_Line("Hello, world!"); New_Line; Put_Line("I am an Ada program with package use.");end
Hello;
For types
with
Ada.Text_IO;procedure
Hellois
use
type
Ada.Text_IO.File_Typebegin
Ada.Text_IO.Put_Line("Hello, world!"); Ada.Text_IO.New_Line; Ada.Text_IO.Put_Line("I am an Ada program with package use.");end
Hello;
Representation clause
For attributes
type
Day_Of_Monthis
range
1 .. 31;for
Day_Of_Month'Sizeuse
8; -- 8 bitsfor
Day_Of_Month'Alignmentuse
1; -- 1 byte
For records
type
Device_Registeris
record
Ready : Status_Flag; Error : Error_Flag; Data : Unsigned_16;end
record
;for
Device_Registeruse
record
Readyat
0range
0 .. 0; Errorat
0range
1 .. 1; -- Reserved bits Dataat
0range
16 .. 31;end
record
;
For enumerations
type
Status_Flagis
(Ready, Wait);for
Status_Flaguse
(Ready => 0, Wait => 1);
See also
Wikibook
Ada Reference Manual
- 8.3 Visibility (Annotated)
- 8.4 Use Clauses (Annotated)
- 13.3 Operational and Representation Attributes (Annotated)
- 13.4 Enumeration Representation Clauses (Annotated)
- 13.5.1 Record Representation Clauses (Annotated)
Ada Quality and Style Guide
Ada Keywords | ||||
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abort
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else
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new
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return
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abs
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elsif
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not
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reverse
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abstract (Ada 95)
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end
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null
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accept
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entry
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select
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access
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exception
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of
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separate
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aliased (Ada 95)
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exit
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or
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some (Ada 2012)
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all
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others
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subtype
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and
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for
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out
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synchronized (Ada 2005)
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array
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function
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overriding (Ada 2005)
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at
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tagged (Ada 95)
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generic
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package
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task
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begin
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goto
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parallel (Ada 2022)
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terminate
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body
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pragma
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then
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if
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private
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type
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case
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in
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procedure
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constant
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interface (Ada 2005)
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protected (Ada 95)
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until (Ada 95)
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is
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use
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declare
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raise
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delay
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limited
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range
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when
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delta
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loop
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record
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while
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digits
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rem
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with
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do
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mod
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renames
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requeue (Ada 95)
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xor
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