# --------------------
# force context
# --------------------
sub VOID (&) {
print "VOID:\t";
$_[0]->();
return;
}
sub LIST (&) {
print "LIST:\t";
() = $_[0]->();
return;
}
sub SCALAR (&) {
print "SCALAR:\t";
scalar $_[0]->();
return;
}
# --------------------
# tests
# --------------------
sub tst_context {
unless (defined wantarray) {
print "is void\n";
} elsif (wantarray) {
print "is list\n";
} else {
print "is scalar\n";
}
}
SCALAR { tst_context() };
LIST { tst_context() };
VOID { tst_context() };
# --------------------
# implicit_returns
# --------------------
sub implicit_returns {
print "implicit_returns(@_)\t";
if ($_[0]) {
tst_context() # caller's context
} else {
tst_context() # caller's context
}
}
SCALAR { implicit_returns(1) };
SCALAR { implicit_returns(0) };
LIST { implicit_returns(1) };
LIST { implicit_returns(0) };
VOID { implicit_returns(1) };
VOID { implicit_returns(0) };
# --------------------
# no_implicit_returns
# --------------------
sub no_implicit_returns {
print "no_implicit_returns(@_)\t";
if ($_[0]) {
tst_context() # void context
} else {
tst_context() # void context
}
return; # last execution!
}
SCALAR { no_implicit_returns(1) };
SCALAR { no_implicit_returns(0) };
LIST { no_implicit_returns(1) };
LIST { no_implicit_returns(0) };
VOID { no_implicit_returns(1) };
VOID { no_implicit_returns(0) };
####
SCALAR: is scalar
LIST: is list
VOID: is void
SCALAR: implicit_returns(1) is scalar
SCALAR: implicit_returns(0) is scalar
LIST: implicit_returns(1) is list
LIST: implicit_returns(0) is list
VOID: implicit_returns(1) is void
VOID: implicit_returns(0) is void
SCALAR: no_implicit_returns(1) is void
SCALAR: no_implicit_returns(0) is void
LIST: no_implicit_returns(1) is void
LIST: no_implicit_returns(0) is void
VOID: no_implicit_returns(1) is void
VOID: no_implicit_returns(0) is void
##
##
# --------------------
# eval
# --------------------
LIST { eval "print 'eval '; return tst_context(); 'never executed'" };
#-> LIST: eval is list