nagler@olsen.UUCP (Robert Nagler) (08/26/87)
>I sent a message on 22nd July to info-modula-2 about one-pass compilation. >I was surprised to receive only three replies (from Chuck Bilbe, I think Randy mentioned a minor problem in receiving replies, because your mail address didn't work. I tried sending a reply directly to you, but it bounced and I just gave up. In answer to the question posed: >I would be interested to hear of any other difficulties that a one-pass >compiler would have in compiling the language defined by the Report. I would first like to change the system to a guilty until proven innocent version as follows: Why do we need to remove the loose declaration order of Modula-2? The answers to this question are: 1) The compiler will go faster. 2) "Use before declaration is an abomination" -- Randy Bush. In response to answer (1), I would like ask how much faster the compiler will go in comparison to the average compilation/link sequence of a typical M2 program. My initial impression would be 10 to 20% faster, but then I am not a compiler writer. The speed improvement on a 10 second compile doesn't seem worth it in comparison to the amount of time it takes a programmmer to verify that a module will be fed into the compiler in the "correct" order. Answer (2) is an interesting opinion which Dr. Wirth allowed us to explore. After using C and Pascal, I find the loose order of declaration in M2 allows the programmer to put the important concepts at the top of the module where they are seen first. I wonder if (2) is more applicable to systems which require programmers to use cross-referenced listings as opposed to ones which supply multi-window text editors. In any event, I do request that the question be rephrased to account for the large body of Modula-2 code which may or may not follow this upward-incompatible restriction. Rob
labbe@DMC-CRC.ARPA.UUCP (09/01/87)
In some simulation models using a one-pass language may increase the complexity of a software package by at least an order of ma- gnitude. If multiple-pass compilers can improve the quality of the software writen then I vote for it! Paul Labbe' CRC or DREO, Ottawa, Canada, K1A 0Z4. Telehone:(613) 998-2020.
randy@oresoft.UUCP (Randy Bush) (09/04/87)
labbe@DMC-CRC.ARPA (Paul Labbe) writes: >In some simulation models using a one-pass language may increase >the complexity of a software package by at least an order of ma- >gnitude. Being a bit slow, I would appreciate an example or explanation. -- Randy Bush, Compiler Group, Oregon Software, Portland Oregon (503) 245-2202 uucp: ..!tektronix!oresoft!randy Telemail: RBush Fidonet: 1:105/6