templater: add IntoTemplateProperty::try_into_cmp

These methods will be used to add `>`, `>=`, `<`, and `<=` operators to
the template language.

cli/src/commit_templater.rs

@@ -14,6 +14,7 @@
 
 use std::any::Any;
 use std::cmp::max;
+use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::io;
 use std::rc::Rc;
@@ -427,6 +428,27 @@ impl<'repo> IntoTemplateProperty<'repo> for CommitTemplatePropertyKind<'repo> {
             (CommitTemplatePropertyKind::TreeDiff(_), _) => None,
         }
     }
+
+    fn try_into_cmp(
+        self,
+        other: Self,
+    ) -> Option<Box<dyn TemplateProperty<Output = Ordering> + 'repo>> {
+        match (self, other) {
+            (CommitTemplatePropertyKind::Core(lhs), CommitTemplatePropertyKind::Core(rhs)) => {
+                lhs.try_into_cmp(rhs)
+            }
+            (CommitTemplatePropertyKind::Core(_), _) => None,
+            (CommitTemplatePropertyKind::Commit(_), _) => None,
+            (CommitTemplatePropertyKind::CommitOpt(_), _) => None,
+            (CommitTemplatePropertyKind::CommitList(_), _) => None,
+            (CommitTemplatePropertyKind::RefName(_), _) => None,
+            (CommitTemplatePropertyKind::RefNameOpt(_), _) => None,
+            (CommitTemplatePropertyKind::RefNameList(_), _) => None,
+            (CommitTemplatePropertyKind::CommitOrChangeId(_), _) => None,
+            (CommitTemplatePropertyKind::ShortestIdPrefix(_), _) => None,
+            (CommitTemplatePropertyKind::TreeDiff(_), _) => None,
+        }
+    }
 }
 
 /// Table of functions that translate method call node of self type `T`.

cli/src/generic_templater.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::cmp::Ordering;
 use std::collections::HashMap;
 
 use crate::template_builder;
@@ -177,6 +178,19 @@ impl<'a, C: 'a> IntoTemplateProperty<'a> for GenericTemplatePropertyKind<'a, C>
             (GenericTemplatePropertyKind::Self_(_), _) => None,
         }
     }
+
+    fn try_into_cmp(
+        self,
+        other: Self,
+    ) -> Option<Box<dyn TemplateProperty<Output = Ordering> + 'a>> {
+        match (self, other) {
+            (GenericTemplatePropertyKind::Core(lhs), GenericTemplatePropertyKind::Core(rhs)) => {
+                lhs.try_into_cmp(rhs)
+            }
+            (GenericTemplatePropertyKind::Core(_), _) => None,
+            (GenericTemplatePropertyKind::Self_(_), _) => None,
+        }
+    }
 }
 
 /// Function that translates keyword (or 0-ary method call node of the self type

cli/src/operation_templater.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use std::any::Any;
+use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::io;
 
@@ -200,6 +201,18 @@ impl IntoTemplateProperty<'static> for OperationTemplatePropertyKind {
             (OperationTemplatePropertyKind::OperationId(_), _) => None,
         }
     }
+
+    fn try_into_cmp(self, other: Self) -> Option<Box<dyn TemplateProperty<Output = Ordering>>> {
+        match (self, other) {
+            (
+                OperationTemplatePropertyKind::Core(lhs),
+                OperationTemplatePropertyKind::Core(rhs),
+            ) => lhs.try_into_cmp(rhs),
+            (OperationTemplatePropertyKind::Core(_), _) => None,
+            (OperationTemplatePropertyKind::Operation(_), _) => None,
+            (OperationTemplatePropertyKind::OperationId(_), _) => None,
+        }
+    }
 }
 
 /// Table of functions that translate method call node of self type `T`.

cli/src/template_builder.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::io;
 
@@ -165,6 +166,10 @@ pub trait IntoTemplateProperty<'a> {
 
     /// Transforms into a property that will evaluate to `self == other`.
     fn try_into_eq(self, other: Self) -> Option<Box<dyn TemplateProperty<Output = bool> + 'a>>;
+
+    /// Transforms into a property that will evaluate to an [`Ordering`].
+    fn try_into_cmp(self, other: Self)
+        -> Option<Box<dyn TemplateProperty<Output = Ordering> + 'a>>;
 }
 
 pub enum CoreTemplatePropertyKind<'a> {
@@ -294,6 +299,28 @@ impl<'a> IntoTemplateProperty<'a> for CoreTemplatePropertyKind<'a> {
             (CoreTemplatePropertyKind::ListTemplate(_), _) => None,
         }
     }
+
+    fn try_into_cmp(
+        self,
+        other: Self,
+    ) -> Option<Box<dyn TemplateProperty<Output = Ordering> + 'a>> {
+        match (self, other) {
+            (CoreTemplatePropertyKind::Integer(lhs), CoreTemplatePropertyKind::Integer(rhs)) => {
+                Some(Box::new((lhs, rhs).map(|(l, r)| l.cmp(&r))))
+            }
+            (CoreTemplatePropertyKind::String(_), _) => None,
+            (CoreTemplatePropertyKind::StringList(_), _) => None,
+            (CoreTemplatePropertyKind::Boolean(_), _) => None,
+            (CoreTemplatePropertyKind::Integer(_), _) => None,
+            (CoreTemplatePropertyKind::IntegerOpt(_), _) => None,
+            (CoreTemplatePropertyKind::Signature(_), _) => None,
+            (CoreTemplatePropertyKind::SizeHint(_), _) => None,
+            (CoreTemplatePropertyKind::Timestamp(_), _) => None,
+            (CoreTemplatePropertyKind::TimestampRange(_), _) => None,
+            (CoreTemplatePropertyKind::Template(_), _) => None,
+            (CoreTemplatePropertyKind::ListTemplate(_), _) => None,
+        }
+    }
 }
 
 /// Function that translates global function call node.
@@ -540,6 +567,13 @@ impl<'a, P: IntoTemplateProperty<'a>> Expression<P> {
     pub fn try_into_eq(self, other: Self) -> Option<Box<dyn TemplateProperty<Output = bool> + 'a>> {
         self.property.try_into_eq(other.property)
     }
+
+    pub fn try_into_cmp(
+        self,
+        other: Self,
+    ) -> Option<Box<dyn TemplateProperty<Output = Ordering> + 'a>> {
+        self.property.try_into_cmp(other.property)
+    }
 }
 
 pub struct BuildContext<'i, P> {