Macro SPITBOL—a SNOBOL4 compiler

摘要

AbstractA fast and compact compiler/interpreter for SPITBOL (a variant of SNOBOL4) has been written in a machine‐independent macro assembly language and implemented initially on the ICL 1900 range of computers. The interpreter uses a novel form of indirect polish code which assists portability. Compile‐time pre‐evaluation of constant expressions has proved to be a worthwhile optimization. A description is given in some detail of the simple but rapid scheme, requiring no marker bits, employed for garbage colle