Hi Erik, > I know I (ab)use 'fill' / 'macro' too much in my code, but I often want > to insert (not splice) the result of some calculation. Would you consider > a new '_' syntax within 'fill' forms? > > : (fill (1 2 _ (+ 1 2)) > -> (1 2 3)
Hmm, I would not be very happy if we invent yet another special symbol, in addition to the existing '^'. This might even break programs already having data with '_' symbols. > This can currently be accomplished a few different ways > > : (let X (+ 1 2) (fill (1 2 X) 'X)) > : (let @X (+ 1 2) (macro (1 2 @X))) I suppose you mean (let @X (+ 1 2) (fill (1 2 @X))), 'macro' uses 'fill' internally but then immediately evaluates the result. > : (fill (1 2 ^ (list (+ 1 2))) So yes, these are the three variants we currently have for 'fill'. > The first two are quite verbose for what is usually a simple or concisely > expressed calculation. The last one is ugly. I agree with you. Though in reality we often have the desired values already in variables, so that explicit 'let's are not needed. But I also would like to have an elegant way to achieve what you described. > Thoughts? What about some middle way? We stick with '^' only, but make it behave more intelligent: 1. If the result of the evaluation is a list, we get the same result as now. 2. But if the result is an atom, it is automatically 'cons'ed into a cell. This would not break any existing programs, as atomic results were useless. So we would get : (fill (1 2 ^(list (+ 1 2))) # Current semantics -> (1 2 3) : (fill (1 2 ^(+ 1 2)) # New behavior -> (1 2 3) What do you think? ☺/ A!ex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
