Questions tagged [rust-decl-macros]
28 questions
1
vote
1 answer
Is there a way to pass a function as a parameter of a macro?
I'm trying to write a function similar to g_signal_connect_swapped in gtk+.
macro_rules! connect_clicked_swap {
($widget: tt,$other_widget: expr,$function: ident) => {
$widget.connect_clicked(|widget| $function($other_widget))
…
Kofi
- 525
- 6
- 15
1
vote
2 answers
Use local bindings at call site in Rust "macro_rules" macros
Consider the following snippet:
macro_rules! quick_hello {
($to_print:expr) => {
{
let h = "hello";
println!("{}", $to_print)
}
}
}
fn main() {
quick_hello!(h);
}
If I compile it, I…
Dincio
- 1,010
- 1
- 13
- 25
1
vote
1 answer
Generate attribute value via macro
Suppose I have an ident input parameter named module_name. How can I generate the value of the attribute through this parameter?
In simple terms, I want to generate something like this:
macro_rules! import_mod {
( $module_name:ident ) => {
…
Hentioe
- 228
- 1
- 9
1
vote
1 answer
How to implement a macro that defines a new public type and returns an instance of that type?
I want to implement a struct using macro_rules! because the generics require a lot of boilerplate and trait hunting.
The struct in question has a hash table inside but the key and the value types are to be provided by the user. The code is as…
noconst
- 639
- 4
- 15
1
vote
1 answer
Is there a way to "do macro stuff" in an attribute without a procedural macro?
Specifically, I'm trying to put macro output into a doc comment. I was excited that this does exactly what I want:
/// foo
///
#[doc="bar\n\nbaz"]
///
/// quux
struct Dummy;
The next step would be to replace that string with my content. According…
Silly Freak
- 4,061
- 1
- 36
- 58
0
votes
1 answer
How to concat two variables to create an identifier in a declarative macro?
I want to write a macro to support parameterized tests, and got the following code from AI, but got errors on one line:
#[macro_export]
macro_rules! parameterize {
($name:ident, $params:pat, {$($test_name:ident : ($($args:expr),*)),*},…
Zach
- 5,715
- 12
- 47
- 62
0
votes
2 answers
How can I operate on pairs of arguments to macro_rules?
I am building a simple feed forward neural network at compile time using const generics and macros. These are a bunch of matrices one after the other.
I have created the network! macro, which works like this:
network!(2, 4, 1)
The first item is…
codearm
- 185
- 1
- 9
0
votes
0 answers
How do I use Rust macros in the same crate?
I have the sources as:
src/
main.rs
memory.rs
chunk.rs
memory.rs
I have a macro:
#[macro_export]
macro_rules! grow_capacity {
( $x:expr ) => {
{
if $x < 8 { 8 } else { $x * 2 }
}
};
}
chunk.rs
I want to…
knh190
- 2,744
- 1
- 16
- 30
0
votes
1 answer
Can I define a macro which will expand into a function call?
I've (naively) tried this, but it doesn't print anything to the screen:
macro_rules! foo {
($suffix:tt, $arg:expr) => {
concat!("foo", $suffix, "(", $arg, ")");
};
}
fn foo_i32(x: i32) {
println!("i32 {}", x);
}
fn foo_bool(x:…
Shmoopy
- 5,334
- 4
- 36
- 72
0
votes
2 answers
Macro to build enum with different "kinds" of elements
I am trying to come up with a macro which I would call like
create_states!(S0, S1, final S2, final S3);
It will create an enum to represent state machine states and some of them will be final (accepting) states - S2, S3. The resulting enum and its…
Eugene Sh.
- 17,802
- 8
- 40
- 61
0
votes
1 answer
Why do I get "unexpected token" when trying to call an inner macro with the argument of an outer macro?
I don't understand this failure while trying to pass the expression received by the higher! macro to the lower! macro:
// A low-level macro using only Rust primitives.
macro_rules! lower {
(x, $a:expr) => {
println!("x is {}", $a);
…
iago-lito
- 3,098
- 3
- 29
- 54
0
votes
1 answer
Macro matching tokens recursive expansion
I'm triying to implement a macro that will expand a brainfuck program (after starting with some simpler code, in which I had problems coming up with a solution already: How to parse single tokens in rust macros). The problem is that at some point of…
Netwave
- 40,134
- 6
- 50
- 93
0
votes
2 answers
Tuple indexing in macro
I'm trying to index data tuple in macro that generate signature for trait implementation, but have some errors. Can I index tuple or need another solution? Hack with tuple_index I found in google but it not works for…
Alexander Kudzin
- 13
- 4