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Bill Birch <birchb1024@xxxxxxxxx> wrote: > Re: http://srfi.schemers.org/srfi-110/srfi-110.html#genyris Thanks so much for posting! > I have made some syntactic decisions which I regard as restricting > programmers to write in a better style. For example not allowing lists to > wrap encourages more smaller functions. That's OK for source code, however > when loading data files one should not restrict the structure. One > difficulty with a syntax that defaults to lists is that something special > needs to be done for atoms. > > Example (a b c (d e f) xx) is problematic since xx is subordinate but is > not a list. So in Genyris I was forced to add a leading 'continuation' > character ~. Which gives me: > > quote > : a b c > : d e f > : ~xx > : > (a b c (d e f) xx) # PairSource > > There is another (obvious) way to wrap lists in Genyris just place > a = at the end of the line. example: > > list 1 2 3 4 5 = > : 6 7 8 > : > (1 2 3 4 5 6 7 8) # Pair > > In practice I don't often use line continuation in code. Great points. I plan to cut-and-paste the above text (with credit) into the SRFI-110. Although I've made different decisions in sweet-expressions, I think it's helpful to see the contrast. > One thing to remember is that indentation may force you to re-arrange > functions to suit the constraints of indentation. For example I had a > function 'tag' which took two arguments, an expression and a class. e.g. > tag (+ 2 3) Inches > > But when the expression begins to get complex it made more sense to > re-order the function to give tag <class> <expression> simply so the > expression could grow on the subordinate indents. example: ... > So if you use indented syntax expect the language itself to change! Fair point. If it's just a matter of reordering arguments for convenience, macros should be able to handle that nicely, but I think that's a plausible general principle. Lisp syntax has (in my opinion) ossified. Indentation adds a new dimension to syntax, and thus creates new possibilities for ease-of-reading. > Cheers, Thanks! And thanks very much for your comments. --- David A. Wheeler