| OCR Text |
Show \ J SB By these means the user may entertain himself by performing calculations, editing text, generating new compilers, and generally going where his thoughts lead him. When he desires to cease running, he simply types in a leave- This is the coroutine exit command and, since . the routine which called him is the process scheduler itself, his process is passivated and the reentry point retained. On the next day (or next week) when he again types. in his password, his process is reactivated and control is passed to the reentry point; he is where he was the last time on the machine. This is why files (and file handling systems) are unnecessary on the FLEX machine. Any declara-tions he may have made (and possibly stored data in), have been saved to be used again. Scope of the User The user at the console is considered to be inside a process description which in turn is interior to the FLEX system and environment. This concept of system globality fits well the FLEX philosophy and provides a convenient meane of allowing the user access to entities such as the FLEX language tables themselves, reserved identifiers whose meaning he may wish to redefine, etc. |
