Struct swc_common::hygiene::SyntaxContext [−][src]
pub struct SyntaxContext(_);
Expand description
A SyntaxContext represents a chain of macro expansions (represented by marks).
Implementations
Extend a syntax context with a given mark and default transparency for that mark.
Pulls a single mark off of the syntax context. This effectively moves the context up one macro definition level. That is, if we have a nested macro definition as follows:
macro_rules! f {
macro_rules! g {
...
}
}
and we have a SyntaxContext that is referring to something declared by an invocation of g (call it g1), calling remove_mark will result in the SyntaxContext for the invocation of f that created g1. Returns the mark that was removed.
Adjust this context for resolution in a scope created by the given
expansion. For example, consider the following three resolutions of
f
:
mod foo {
pub fn f() {}
} // `f`'s `SyntaxContext` is empty.
m!(f);
macro m($f:ident) {
mod bar {
pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
pub fn $f() {} // `$f`'s `SyntaxContext` is empty.
}
foo::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
//^ Since `mod foo` is outside this expansion, `adjust` removes the mark from `f`,
//| and it resolves to `::foo::f`.
bar::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
//^ Since `mod bar` not outside this expansion, `adjust` does not change `f`,
//| and it resolves to `::bar::f`.
bar::$f(); // `f`'s `SyntaxContext` is empty.
//^ Since `mod bar` is not outside this expansion, `adjust` does not change `$f`,
//| and it resolves to `::bar::$f`.
}
This returns the expansion whose definition scope we use to privacy
check the resolution, or None
if we privacy check as usual (i.e.
not w.r.t. a macro definition scope).
pub fn glob_adjust(
&mut self,
expansion: Mark,
glob_ctxt: SyntaxContext
) -> Option<Option<Mark>>
pub fn glob_adjust(
&mut self,
expansion: Mark,
glob_ctxt: SyntaxContext
) -> Option<Option<Mark>>
Adjust this context for resolution in a scope created by the given
expansion via a glob import with the given SyntaxContext
.
For example:
m!(f);
macro m($i:ident) {
mod foo {
pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
pub fn $i() {} // `$i`'s `SyntaxContext` is empty.
}
n(f);
macro n($j:ident) {
use foo::*;
f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n`
//^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::f`.
$i(); // `$i`'s `SyntaxContext` has a mark from `n`
//^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::$i`.
$j(); // `$j`'s `SyntaxContext` has a mark from `m`
//^ This cannot be glob-adjusted, so this is a resolution error.
}
}
This returns None
if the context cannot be glob-adjusted.
Otherwise, it returns the scope to use when privacy checking (see
adjust
for details).
pub fn reverse_glob_adjust(
&mut self,
expansion: Mark,
glob_ctxt: SyntaxContext
) -> Option<Option<Mark>>
pub fn reverse_glob_adjust(
&mut self,
expansion: Mark,
glob_ctxt: SyntaxContext
) -> Option<Option<Mark>>
Undo glob_adjust
if possible:
if let Some(privacy_checking_scope) = self.reverse_glob_adjust(expansion, glob_ctxt) {
assert!(self.glob_adjust(expansion, glob_ctxt) == Some(privacy_checking_scope));
}
Trait Implementations
Returns the “default value” for a type. Read more
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Auto Trait Implementations
impl RefUnwindSafe for SyntaxContext
impl Send for SyntaxContext
impl Sync for SyntaxContext
impl Unpin for SyntaxContext
impl UnwindSafe for SyntaxContext
Blanket Implementations
Mutably borrows from an owned value. Read more