Stropping
| “ | I notice, in some of your sample programs, that you are not underlining or stropping anything. -- Mailloux |
” |
In ALGOL family languages it is necessary to distinguish between identifiers and basic symbols of the language. In printed texts this was usually accomplished by printing basic symbols in boldface or underlined (begin or begin for example).
In source programs some stropping technique had to be used. In many ALGOL like languages before ALGOL 68-R this was accomplished by enclosing basic symbols in single quote characters ('begin' for example). In ALGOL 68-R basic symbols could be distinguished by writing the in upper case, lower case being used for identifiers.
As ALGOL 68-R was implemented on a machine with 6 bit bytes (and hence a 64 character set) this was quite complicated and, at least initially, programs had to be composed on paper tape using a Flexowriter.
Partly based on the experience of ALGOL 68-R the revised report on ALGOL 68 specified hardware representations for the language, including UPPER stropping.
Read more about this topic: ALGOL 68R