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# 1 "scope.cppo"
(* This example shows that the definition of FOO that is nested inside
the (multi-line) definition of BAR affects only the body of the
definition of BAR. It does not affect the text that follows a call
to BAR. So, a multi-line macro definition acts as a scope delimiter. *)
# 11 "scope.cppo"
"definition of FOO at the top level"
# 11 "scope.cppo"
(* expands to "definition of FOO at the top level" *)
# 12 "scope.cppo"
"definition of FOO inside BAR" (* expands to "definition of FOO inside BAR" *)
# 13 "scope.cppo"
"definition of FOO at the top level"
# 13 "scope.cppo"
(* expands to "definition of FOO at the top level" *)
(* If one wishes to delimit a scope, without actually defining a macro,
one can use #scope ... #endscope. *)
# 20 "scope.cppo"
"first definition of HELLO"
# 20 "scope.cppo"
(* expands to "first definition of HELLO" *)
# 24 "scope.cppo"
"second definition of HELLO"
# 24 "scope.cppo"
(* expands to "second definition of HELLO" *)
HELLO (* this does not expand *)
(* The effect of #scope ... #endscope can be simulated by writing
#def DUMMY ... #enddef DUMMY #undef DUMMY
but this is a bit unnatural. *)
# 36 "scope.cppo"
"definition of HELLO inside the scope" (* expands to "definition of HELLO inside the scope" *)
# 38 "scope.cppo"
HELLO (* this does not expand *)
(* Another simple example. *)
# 44 "scope.cppo"
let x =
# 44 "scope.cppo"
"I am defined"
# 44 "scope.cppo"
(* expands to "I am defined" *)
# 47 "scope.cppo"
let y =
# 47 "scope.cppo"
42
# 47 "scope.cppo"
(* expands to 42 *)
(* Check that the effect of #undef is also local.
This example relies on the above definition of HI. *)
# 54 "scope.cppo"
let qwd = HI (* HI is not recognized as a macro and expands to itself *)
let z =
# 56 "scope.cppo"
42
# 56 "scope.cppo"
(* expands to 42 *)
(* Scopes can be nested. *)
# 61 "scope.cppo"
let x =
# 61 "scope.cppo"
0
# 61 "scope.cppo"
(* expands to 0 *)
# 65 "scope.cppo"
let y =
# 65 "scope.cppo"
1
# 65 "scope.cppo"
(* expands to 1 *)
# 69 "scope.cppo"
let z =
# 69 "scope.cppo"
2
# 69 "scope.cppo"
(* expands to 2 *)
let _ =
# 71 "scope.cppo"
1
# 71 "scope.cppo"
(* expands to 1 *)
let _ =
# 73 "scope.cppo"
0
# 73 "scope.cppo"
(* expands to 0 *)
(* Another example of nesting. *)
# 81 "scope.cppo"
let message1 =
# 81 "scope.cppo"
"Hello, "
# 81 "scope.cppo"
^
# 81 "scope.cppo"
"man"
# 83 "scope.cppo"
(* Here, MAN is no longer defined, but HELLO still is. *)
let message2 =
# 84 "scope.cppo"
"Hello, "
# 84 "scope.cppo"
^ "world"
|
