5.3 TYPES In addition to determining the possible values for variables and subtype names, type distinctions can be very valuable aids in developing safe, readable, and understandable code. Types clarify the structure of your data and can limit or restrict the operations performed on that data. "Keeping types distinct has been found to be a very powerful means of detecting logical mistakes when a program is written and to give valuable assistance whenever the program is being subsequently maintained" (Pyle 1985). Take advantage of Ada's strong typing capability in the form of subtypes, derived types, task types, protected types, private types, and limited private types. The guidelines encourage much code to be written to ensure strong typing. While it might appear that there would be execution penalties for this amount of code, this is usually not the case. In contrast to other conventional languages, Ada has a less direct relationship between the amount of code that is written and the size of the resulting executable program. Most of the strong type checking is performed at compilation time rather than execution time, so the size of the executable code is not greatly affected. For guidelines on specific kinds of data structures and tagged types, see Guidelines 5.4 and 9.2.1, respectively. < Previous Page Search Contents Index Next Page > 1 2 3 4 5 6 7 8 9 10 11 TOC TOC TOC TOC TOC TOC TOC TOC TOC TOC TOC Appendix References Bibliography
The guidelines encourage much code to be written to ensure strong typing. While it might appear that there would be execution penalties for this amount of code, this is usually not the case. In contrast to other conventional languages, Ada has a less direct relationship between the amount of code that is written and the size of the resulting executable program. Most of the strong type checking is performed at compilation time rather than execution time, so the size of the executable code is not greatly affected.
For guidelines on specific kinds of data structures and tagged types, see Guidelines 5.4 and 9.2.1, respectively.