#!ruby -n
r=0
def t(s)s=~/^`/?(a,_=t$'
b,c=t _
[a+"[#{b}]",c]):[s[/./],$']end
eval'f=Lx|r+=1}
i=Lx|x}
k=Lx|Ly|x}}
s=Lx|Ly|Lz|x[z][y[z]]}}}
'.gsub('L','proc{|')+t("``"+$_+"fp")[0]
p r
Note that non-ascii characters in the above source code will be escaped (such as \x9f).