Comments for Sufficiently Small

Comment on OWL BASIC produces its first executable by Les May

Les May — Sat, 13 Feb 2010 19:35:17 +0000

I’m glad to hear that the BBC Basic/CLR project is going forward and that you have decided to give it a name ‘Owl Basic’ which suggests you are not going to slavishly follow the road to exact compatability with the ARM interpreter.

If I read the last post correctly Owl Basic will permit a space between the keyword ‘proc’ and the procedure name, i.e. def proc DoThis, rather than def proc_DoThis. This is a welcome change and has one very interesting consequence.

I use BBC4W with an external editor, PSPad. This editor allows the use of user produced syntax files and the control over keyword colouring and font. As it operates on whole words it cannot colour the keywork ‘proc’ in proc_DoThis. Allowing a space after proc will allow syntax colouring to be used.

PSPad allows an external compiler (or interpreter) to be called so it will only be a matter of pointing it at the Owl Basic compiler.

If you are willing to go a little bit further in dropping complete compatibility with the ARM interpreter the way functions are defined and called would benefit from a bit of tidying up. In particular an ‘endfunc’ and a specific keyword to return a value from the function would bring it closer to modern ways of doing things. It might mean changing ‘return’ for variables passed by reference to ‘ref’.

Comment on Writing a BBC BASIC compiler for the CLR by Les May

Les May — Sat, 06 Feb 2010 16:47:13 +0000

I invite MUNCH to carefully re-read what I actually said in my posting. I did not say that OBERON does not discard BEBIN/END in control structures. None of the descendents of Pascal implement full closure of control structures. The single word ‘END’ is used to terminate all except the REPEAT..UNTIL loop. If full closure were implemented the examples given would read RECORD..ENDRECORD, FOR..ENDFOR etc. This may be just ’syntactic sugar’ but it enhances readability. We spend more time reading programs than we do writing them, so readability is important. Lack of ambiguity is the first line of defence against logical errors in a program.

There is a price to pay for this ‘verbosity’. It produces larger source files and requires a bit more typing. The latter problem can be overcome by means of a good editor which will check for incorrectly closed control structures and automatically add in the needed terminating word. Interpreters written to the COMAL80 standard accept ‘NEXT’ and replace it with ‘ENDFOR’. If this could be done 30 years ago it could be done now with compiled languages.

Zonnon corrects one of the unfortunate aspects of MODULA 2 and OBERON which reduce their readability: their insistance on upper case keywords. It does not implement ‘full closure’. Editors of code for interpreters to the COMAL80 standard accept lower case keyword and silently change it the upper case. I know of only one editor of Component Pascal, a descendent of OBERON 2, which does this. Upper case keywords were fine when everyone used character based displays.

If anyone ever does produce a new COMAL interpreter for the CLR I hope the use of upper case keywords will be dropped. A good syntax highlighting editor would be far better.

One of the factors in making the BBC Basic for Windows so successful is the built in editor. Not perfect but good.

Comment on Writing a BBC BASIC compiler for the CLR by munch

munch — Tue, 26 Jan 2010 02:58:44 +0000

Oberon absolutely discards BEGIN/END in control structures. I’m not sure why Les says it doesn’t, and belies an ignorance of the language from lack of use. The only use for BEGIN in Oberon is distinguishing program code from declarations in procedures.

RECORD…END, FOR…END, WHILE…END, REPEAT…UNTIL, IF…(ELSE)…(ELSIF)…END, etc.

I invite Les to reconsider his position on Oberon.

Comment on Installing Eclipse on Windows Vista by Greg Fenton

Greg Fenton — Mon, 02 Nov 2009 19:22:00 +0000

Have you seen this thread:

http://dev.eclipse.org/blogs/francis/2009/05/24/rcp-p2-vista-and-virtualstore/

Comment on Installing Eclipse on Windows Vista by Robert Smallshire

Robert Smallshire — Sat, 31 Oct 2009 21:56:55 +0000

Yes – I tried again on another Vista machine, and then mondo’s simple procedure above, didn’t work for me. I had to visit this page to follow the full procedure

Comment on OWL BASIC runtime library takes shape by Robert Smallshire

Robert Smallshire — Sat, 31 Oct 2009 21:51:41 +0000

@Richard Russell You're correct that these aren't available through GDI+. But GDI+ given us an easy-to-use .NET API which allows us to quickly and easily implement much of what we need to cover. Our VDU drivers are pretty well decoupled from the actual rendering mechanism, so it won't be much work to provide a rendering backend for another API, such as GDI as you suggest, or possibly OpenGL to be more cross platform.

Comment on Installing Eclipse on Windows Vista by fuffa

fuffa — Thu, 29 Oct 2009 15:20:45 +0000

@Robert Smallshire So..., any results yet?

Comment on OWL BASIC runtime library takes shape by Richard Russell

Richard Russell — Sun, 18 Oct 2009 21:43:40 +0000

Since you’re using GDI+ to implement the VDU commands, how are you managing to provide the GCOL ‘logical plotting’ modes (OR, AND, XOR, NOT)? I thought it was one of the limitations of GDI+ that it provided no equivalent to GDI’s SetROP2 functionality.

Comment on Installing Eclipse on Windows Vista by Robert Smallshire

Robert Smallshire — Tue, 29 Sep 2009 15:16:23 +0000

@mondo Unfortunately, the approach you describe, which is what I usually do when copying executables to Program Files, didn't work for me with Eclipse, hence the rather involved procedure above. I'll have the opportunity to install Eclipse again on another Vista machine later this week, so I'll report back after another attempt following the more simple, although still somewhat obscure, method.

Comment on Installing Eclipse on Windows Vista by mondo

mondo — Tue, 29 Sep 2009 13:15:23 +0000

Much simpler solution is to first launch eclipse.exe outside of Program Files and in the Security Warning dialog uncheck the ‘Always ask me about running this file’ option. The system will remember this. Then you can move your eclipse into Program Files and it will start without the annoyance. (Setting that option in PF was useless.)