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Parse const param defaults

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This commit is contained in:
Jonas Schievink
2021-04-29 03:07:53 +02:00
parent 9d199486da
commit cb8632d87c
4 changed files with 141 additions and 0 deletions
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32
crates/parser/src/grammar/type_args.rs
View File

@@ -25,6 +25,38 @@ pub(super) fn opt_generic_arg_list(p: &mut Parser, colon_colon_required: bool) {
m.complete(p, GENERIC_ARG_LIST);
}
pub(super) fn const_arg(p: &mut Parser) {
let m = p.start();
// FIXME: duplicates the code below
match p.current() {
T!['{'] => {
expressions::block_expr(p);
m.complete(p, CONST_ARG);
}
k if k.is_literal() => {
expressions::literal(p);
m.complete(p, CONST_ARG);
}
T![true] | T![false] => {
expressions::literal(p);
m.complete(p, CONST_ARG);
}
T![-] => {
let lm = p.start();
p.bump(T![-]);
expressions::literal(p);
lm.complete(p, PREFIX_EXPR);
m.complete(p, CONST_ARG);
}
_ => {
let lm = p.start();
paths::use_path(p);
lm.complete(p, PATH_EXPR);
m.complete(p, CONST_ARG);
}
}
}
// test type_arg
// type A = B<'static, i32, 1, { 2 }, Item=u64, true, false>;
fn generic_arg(p: &mut Parser) {

10
crates/parser/src/grammar/type_params.rs
View File

@@ -70,6 +70,16 @@ fn const_param(p: &mut Parser, m: Marker) {
p.bump(T![const]);
name(p);
types::ascription(p);
// test const_param_defaults
// struct A<const N: i32 = -1>;
// struct B<const N: i32 = {}>;
// struct C<const N: i32 = some::CONST>;
if p.at(T![=]) {
p.bump(T![=]);
type_args::const_arg(p);
}
m.complete(p, CONST_PARAM);
}