Re: patch: C-style string lexing

[David Manura <dm.lua@...>]

Eric Tetz writes:
> > On Jan 30, 2008 5:20 PM, Luiz Henrique de Figueiredo wrote:
> > > This will break expressions like f "A" "B", which is interpreted as
> > > f("A")("B").
> Well, scratch that idea then. :)

How about constant folding string concatenations?  This would require only an
implementation change.  It is currently done for other operators:

$ echo 'return 2+3' | ./luac -p -l -

main <stdin:0,0> (3 instructions, 12 bytes at 0x680e28)
0+ params, 2 slots, 0 upvalues, 0 locals, 1 constant, 0 functions
        1       [1]     LOADK           0 -1    ; 5
        2       [1]     RETURN          0 2
        3       [1]     RETURN          0 1

$ echo 'return "a".."b"' | ./luac -p -l -

main <stdin:0,0> (5 instructions, 20 bytes at 0x680e28)
0+ params, 2 slots, 0 upvalues, 0 locals, 2 constants, 0 functions
        1       [1]     LOADK           0 -1    ; "a"
        2       [1]     LOADK           1 -2    ; "b"
        3       [1]     CONCAT          0 0 1
        4       [1]     RETURN          0 2
        5       [1]     RETURN          0 1

I wonder whether the right-most associativity of concatenation would complicate
this though.