macro_rules! foo {
( $( $( $tok:tt )* ,)* ) => {
[ bar!( $( $tok )* ,)* ]
}
}
Produces error: local ambiguity when calling macro 'foo'
. Because the comma ','
is of type :tt
. I would need a way to match all token trees excluding the coma token.
foo!(
add t0 zero zero,
add t1 t0 a0,
lb t1 0(t1),
)
Should produce:
[
bar!(add t0 zero zero),
bar!(add t1 t0 a0),
bar!(lb t1 0(t1)),
]
TT munching to the rescue!
macro_rules! foo {
(@accumulate [ $($accumulated:tt)* ] [ ]) => { [ $($accumulated)* ] };
(@accumulate [ $($accumulated:tt)* ] [ $($this_line:tt)* ] , $($rest:tt)* ) => {
foo! { @accumulate [
$($accumulated)*
bar!( $($this_line)* ),
] [] $($rest)* }
};
(@accumulate [ $($accumulated:tt)* ] [ $($this_line:tt)* ] $current:tt $($rest:tt)* ) => {
foo! { @accumulate [ $($accumulated)* ] [ $($this_line)* $current ] $($rest)* }
};
( $($t:tt)* ) => { foo! { @accumulate [] [] $($t)* } }
}