Ada Programming/Delimiters/double dot
From Wikibooks, the open-content textbooks collection
- The title given to this book is incorrect due to technical limitations. The correct title is Ada Programming/Delimiters/...
Contents |
The delimiter .. is used to specify ranges in any scalar type.
For example:
- In numeric type definitions:
type Count is range 0 .. Max_Count;
- In subtype definitions:
subtype Week_Day is Day_Name range Monday .. Friday;
- In variable declarations:
Vector_A : Vector (0 .. 31);
- In membership tests:
exit when X in Y .. Y + Epsilon;
- In for loops:
for Day in Day_Name range Monday .. Thursday loop -- ... end loop;
- In arrays:
Vector_A (Vector_A'First .. Vector_A'First + Vector_B'Length - 1) := Vector_B;
[edit] Usage notes
When a whole type range will be specified, it is better to use the Range attribute.
For example, instead of using:
for Day in range Day_Name'First .. Day_Name'Last loop -- ... end loop;
it is better to use:
for Day in Day_Name'Range loop -- ... end loop;
