Symbolics

One thing you can do to optimize a tokenizing interpreter is to precalculate and store the goto and gosub destination and return addresses. This way the interpreter does not have to start at line 0 searching sequentially through the tree for the destination for a gosub but will just go there directly. Of course calculated destinations (ie: 10 if x then gosub x+x+1) totally ruin this system for that line of code. Basic XE and Basic XL from OSS used this feature in thier "FAST" command (a sort of post-tokenized address precompiler) to boost performance. -- ----------------------------------------------------------- Jeffrey S. Worley Technical Services Bits & Bytes Computer Services Inc. 1979B Hendersonville Road Asheville, NC 28803 828-684-8953 - voice 0900-1700 five days 828-687-9284 - 24hr fax Who is General Failure and why is he reading my hard disk? Technoid(a)Cheta.net -----------------------------------------------------------