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On 7/20/2016 7:30 AM, Philipp Janda wrote:
Am 20.07.2016 um 15:20 schröbte Dirk Laurie:.... Suggestion: make the few special characters we have left user-configurable. I.e. introduce metamethod names for !x, x ? y etc even though no native type defines a default meaning for them.IMHO, operators only make code easier to read if you have an intuitive understanding about what the operator is supposed to do and how it relates to other operators in the same expression (e.g. regarding precedence). Otherwise it only makes things harder to parse (for computers and humans alike).
I once encountered a language[1] which had syntax for infix notation function calls, allowing new binary operators to be introduced as simple functions of two arguments. So:
local M=17 -- upvalue for modulus local function addm(a,b) return (a+b)%M end -- modular addition local n = 16 print( n /addm\ 1 ) -- 0Not sure the specific notation of /name\ feels like it fits the tone of Lua code, but it was a convenient way to make arbitrary data types with an expressive grammar. I don't recall if there was a way to declare precedence, or if it was left to right.
[1]: ICL, an early silicon compiler. It has almost completely vanished from visibility, but Ron's thesis that defined the langauge is available. Worth a read if novel parsing techniques interest you. http://authors.library.caltech.edu/26660/2/postscript.pdf
-- Ross Berteig Ross@CheshireEng.com Cheshire Engineering Corp. http://www.CheshireEng.com/ +1 626 303 1602