Small syntactic note (Was Re: string.gsub ...)

[Rici Lake <lua@...>]

It is possibly worth saying that in Lua, as in many languages, ()
is used in two syntactically distinct contexts for two semantically
distinct purposes:

( [exprlist1] )  is a postfix "call" operator
( exp )          is a term

Like prefix/infix "-", the two contexts can easily be distinguished:

-- following a term (prefixexp or prefixexp ':' Name, in the Lua 
grammar):
   ( [exprlist] )  "call" (args)
   -               "binary operator" (binop)
-- following a binop or at the beginning of an expression:
   ( expr )        "term" (prefixexp)
   -               "unary operator" (unop)

It is perhaps the fact that this "pun" is so common that makes
it invisible.