Hello. I started working on Bentley, a new programming language. This
was inspired by and is based on the pseudocode in Jon Bentley's
"Programming Pearls" - a column for the CACM that became a book. The
compiler generates Assembly in a temporary file, then calls up the
assembler to make the program. Currently, the assembly that can be
generated is a subset of the language that can be parsed, but I'm
working on it.

%% rc /n/sources/contrib/pietro/bentley.bundle
...
%% mk
...
%% 8b asm.b
%% 8l -o asm asm.8
%% asm
5
1
%% cat test.b # for what the parser is capable of

The idea is simple: indentation as block style. Instead of

don't forget fortran.

- erik

Indentation by white space is a very bad idea in my experience.
Superficially attractive but ultimately very dangerous. I once spent a
couple of days tracking down a bug caused by a source-to-source code
tool that broke a major program because the code it was injecting into
had indented one more space, causing the injecting code to break the
control flow. It was nearly impossible to track down.

I have lots of other examples of lesser disasters. As code grows,
white space indentation becomes ever more problematic. It's a
maintenance disaster.

Put it this way: It's unwise to make program structure depend on
invisible characters.

-rob

(By 'indentation' of course I mean 'indentation to define structure')

-rob

a white space is something hard to find, some time ago I helped a friend
who couldn't get a mkfile working, he got something like:
"mk: mkfile:6: syntax error; expected one of :<="
all due to a ' ' in what was supposed to be an empty line.

Federico G. Benavento

On May 1, 2008, at 9:52 PM, Rob Pike wrote:

This scenario is why I decided to require hard tabs as indents. You
can't use a space. But a space halts the indentation, so the problem
is still there. The next version will just ignore spaces, and treat
the first non-whitespace character as the beginning of a line.

On May 1, 2008, at 9:26 PM, erik quanstrom wrote:

[off topic] I wonder why it took 20 or so years for Fortran to
introduce IF..ELSE..END IF. Probably after Kernighan and Plauger,
1974, it finally came to Backus' senses. :-P

On May 1, 2008, at 9:12 PM, Federico G. Benavento wrote:

Another thing: lines with only whitespace are naturally ignored (as
far as I know - I am human) and don't break the block structure.

The space in an empty line should be a bug, right?

On May 1, 2008, at 10:21 PM, Pietro Gagliardi wrote:

Pietro Gagliardi wrote:

I don't use Python for this very reason. This is probably why Ruby
exists. I will not use your language for the same reason. By adopting
such draconian white space rules you automatically alienate a large
number of programmers.

I consider this one of the larger mistakes in programming language
design, akin to making the period the most important token in the COBOL
language, or using whitespace as a separator in FORTRAN (which
incidentally lost NASA a space probe.)