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|
// force-host
// no-prefer-dynamic
#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::{TokenStream, TokenTree, Delimiter, Literal, Spacing, Group};
#[proc_macro_attribute]
pub fn foo(attr: TokenStream, input: TokenStream) -> TokenStream {
assert!(attr.is_empty());
let input = input.into_iter().collect::<Vec<_>>();
{
let mut cursor = &input[..];
assert_inline(&mut cursor);
assert_doc(&mut cursor);
assert_inline(&mut cursor);
assert_doc(&mut cursor);
assert_foo(&mut cursor);
assert!(cursor.is_empty());
}
fold_stream(input.into_iter().collect())
}
#[proc_macro_attribute]
pub fn bar(attr: TokenStream, input: TokenStream) -> TokenStream {
assert!(attr.is_empty());
let input = input.into_iter().collect::<Vec<_>>();
{
let mut cursor = &input[..];
assert_inline(&mut cursor);
assert_doc(&mut cursor);
assert_invoc(&mut cursor);
assert_inline(&mut cursor);
assert_doc(&mut cursor);
assert_foo(&mut cursor);
assert!(cursor.is_empty());
}
input.into_iter().collect()
}
fn assert_inline(slice: &mut &[TokenTree]) {
match &slice[0] {
TokenTree::Punct(tt) => assert_eq!(tt.as_char(), '#'),
_ => panic!("expected '#' char"),
}
match &slice[1] {
TokenTree::Group(tt) => assert_eq!(tt.delimiter(), Delimiter::Bracket),
_ => panic!("expected brackets"),
}
*slice = &slice[2..];
}
fn assert_doc(slice: &mut &[TokenTree]) {
match &slice[0] {
TokenTree::Punct(tt) => {
assert_eq!(tt.as_char(), '#');
assert_eq!(tt.spacing(), Spacing::Alone);
}
_ => panic!("expected #"),
}
let inner = match &slice[1] {
TokenTree::Group(tt) => {
assert_eq!(tt.delimiter(), Delimiter::Bracket);
tt.stream()
}
_ => panic!("expected brackets"),
};
let tokens = inner.into_iter().collect::<Vec<_>>();
let tokens = &tokens[..];
if tokens.len() != 3 {
panic!("expected three tokens in doc")
}
match &tokens[0] {
TokenTree::Ident(tt) => assert_eq!("doc", &*tt.to_string()),
_ => panic!("expected `doc`"),
}
match &tokens[1] {
TokenTree::Punct(tt) => {
assert_eq!(tt.as_char(), '=');
assert_eq!(tt.spacing(), Spacing::Alone);
}
_ => panic!("expected equals"),
}
match tokens[2] {
TokenTree::Literal(_) => {}
_ => panic!("expected literal"),
}
*slice = &slice[2..];
}
fn assert_invoc(slice: &mut &[TokenTree]) {
match &slice[0] {
TokenTree::Punct(tt) => assert_eq!(tt.as_char(), '#'),
_ => panic!("expected '#' char"),
}
match &slice[1] {
TokenTree::Group(tt) => assert_eq!(tt.delimiter(), Delimiter::Bracket),
_ => panic!("expected brackets"),
}
*slice = &slice[2..];
}
fn assert_foo(slice: &mut &[TokenTree]) {
match &slice[0] {
TokenTree::Ident(tt) => assert_eq!(&*tt.to_string(), "fn"),
_ => panic!("expected fn"),
}
match &slice[1] {
TokenTree::Ident(tt) => assert_eq!(&*tt.to_string(), "foo"),
_ => panic!("expected foo"),
}
match &slice[2] {
TokenTree::Group(tt) => {
assert_eq!(tt.delimiter(), Delimiter::Parenthesis);
assert!(tt.stream().is_empty());
}
_ => panic!("expected parens"),
}
match &slice[3] {
TokenTree::Group(tt) => assert_eq!(tt.delimiter(), Delimiter::Brace),
_ => panic!("expected braces"),
}
*slice = &slice[4..];
}
fn fold_stream(input: TokenStream) -> TokenStream {
input.into_iter().map(fold_tree).collect()
}
fn fold_tree(input: TokenTree) -> TokenTree {
match input {
TokenTree::Group(b) => {
TokenTree::Group(Group::new(b.delimiter(), fold_stream(b.stream())))
}
TokenTree::Punct(b) => TokenTree::Punct(b),
TokenTree::Ident(a) => TokenTree::Ident(a),
TokenTree::Literal(a) => {
if a.to_string() != "\"foo\"" {
TokenTree::Literal(a)
} else {
TokenTree::Literal(Literal::i32_unsuffixed(3))
}
}
}
}
|
