allow slot to be only :* := :slot/sub= or :slot

src/atom/mod.rs

@@ -79,11 +79,17 @@ pub enum SlotOperator {
 #[derive(Clone, Debug, PartialEq, Eq, Get)]
 pub struct SlotName(#[get(method = "name", kind = "deref")] String);
 
-#[derive(Clone, Debug, PartialEq, Eq, Get)]
-pub struct Slot {
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Slot {
+    Wildcard,
+    Equal {
         primary: Option<SlotName>,
         sub: Option<SlotName>,
-    operator: Option<SlotOperator>,
+    },
+    Name {
+        primary: SlotName,
+        sub: Option<SlotName>,
+    },
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -575,20 +581,30 @@ impl fmt::Display for SlotName {
 
 impl fmt::Display for Slot {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if let Some(slot) = self.primary.as_ref() {
-            write!(f, "{slot}")?;
+        match self {
+            Self::Wildcard => write!(f, "*"),
+            Self::Equal { primary, sub } => {
+                if let Some(primary) = primary {
+                    write!(f, "{primary}")?;
                 }
 
-        if let Some(sub) = self.sub.as_ref() {
+                if let Some(sub) = sub {
                     write!(f, "/{sub}")?;
                 }
 
-        if let Some(operator) = self.operator.as_ref() {
-            write!(f, "{operator}")?;
+                write!(f, "=")
+            }
+            Self::Name { primary, sub } => {
+                write!(f, "{primary}")?;
+
+                if let Some(sub) = sub {
+                    write!(f, "/{sub}")?;
                 }
 
                 Ok(())
             }
+        }
+    }
 }
 
 impl fmt::Display for UseDepNegate {

src/atom/parsers.rs

@@ -186,21 +186,17 @@ impl<'a> Parseable<'a, &'a str> for Slot {
     type Parser = impl Parser<&'a str, Output = Self>;
 
     fn parser() -> Self::Parser {
-        SlotName::parser()
+        let wildcard = tag("*").map(|_| Slot::Wildcard);
+        let equals = SlotName::parser()
             .opt()
             .and(SlotName::parser().preceded_by(tag("/")).opt())
-            .and(SlotOperator::parser().opt())
-            .map(|((primary, sub), operator)| Slot {
-                primary,
-                sub,
-                operator,
-            })
-            .verify_output(|slot| {
-                matches!(
-                    (&slot.primary(), &slot.operator()),
-                    (Some(_) | None, Some(_)) | (Some(_), None)
-                )
-            })
+            .followed_by(tag("="))
+            .map(|(primary, sub)| Slot::Equal { primary, sub });
+        let name = SlotName::parser()
+            .and(SlotName::parser().preceded_by(tag("/")).opt())
+            .map(|(primary, sub)| Slot::Name { primary, sub });
+
+        wildcard.or(equals).or(name)
     }
 }
 
@@ -556,6 +552,7 @@ mod test {
             "=dev-ml/stdio-0.17*t:=[ocamlopt?]",
             ">=dev-libs/libgee-0-8.5:0..8=",
             "<dev-haskell/wai-3.3:=[]",
+            ">=kde-frameworks/kcrash-2.16.0:6*",
         ];
 
         for atom in atoms {