commit_templater: teach elidable (or optional) commit

I think Option<Commit> is the simplest encoding of the log node. The behavior of an Option type is closer to nullable types rather than the Option in Rust. I don't think we would want to write opt.map(|x| x.f()) or opt.unwrap().f(). We can of course add opt?.f() syntax, but it will be a short for "if(opt, opt.f())"?

Yuya Nishihara committed 2 years ago

Commit 2fc7feb1 parent 2afd3412 files · +26 −1Browse files

Unified · Split

2 files

cli/src/commit_templater.rs +20 −1
docs/templates.md +6 −0

cli/src/commit_templater.rs+20−1

 use crate::template_parser::{self, FunctionCallNode, TemplateParseError, TemplateParseResult};
 use crate::templater::{
     self, IntoTemplate, PlainTextFormattedProperty, Template, TemplateProperty,
-    TemplatePropertyExt as _,
+    TemplatePropertyError, TemplatePropertyExt as _,
 };
 use crate::{revset_util, text_util};
                 let build = template_parser::lookup_method("Commit", table, function)?;
                 build(self, build_ctx, property, function)
             }
+            CommitTemplatePropertyKind::CommitOpt(property) => {
+                let table = &self.build_fn_table.commit_methods;
+                let build = template_parser::lookup_method("Commit", table, function)?;
+                let inner_property = property.and_then(|opt| {
+                    opt.ok_or_else(|| TemplatePropertyError("No commit available".into()))
+                });
+                build(self, build_ctx, Box::new(inner_property), function)
+            }
             CommitTemplatePropertyKind::CommitList(property) => {
                 // TODO: migrate to table?
                 template_builder::build_unformattable_list_method(
         CommitTemplatePropertyKind::Commit(Box::new(property))
     }
+    pub fn wrap_commit_opt(
+        property: impl TemplateProperty<Output = Option<Commit>> + 'repo,
+    ) -> CommitTemplatePropertyKind<'repo> {
+        CommitTemplatePropertyKind::CommitOpt(Box::new(property))
+    }
     pub fn wrap_commit_list(
         property: impl TemplateProperty<Output = Vec<Commit>> + 'repo,
     ) -> CommitTemplatePropertyKind<'repo> {
 pub enum CommitTemplatePropertyKind<'repo> {
     Core(CoreTemplatePropertyKind<'repo>),
     Commit(Box<dyn TemplateProperty<Output = Commit> + 'repo>),
+    CommitOpt(Box<dyn TemplateProperty<Output = Option<Commit>> + 'repo>),
     CommitList(Box<dyn TemplateProperty<Output = Vec<Commit>> + 'repo>),
     RefName(Box<dyn TemplateProperty<Output = RefName> + 'repo>),
     RefNameList(Box<dyn TemplateProperty<Output = Vec<RefName>> + 'repo>),
         match self {
             CommitTemplatePropertyKind::Core(property) => property.try_into_boolean(),
             CommitTemplatePropertyKind::Commit(_) => None,
+            CommitTemplatePropertyKind::CommitOpt(property) => {
+                Some(Box::new(property.map(|opt| opt.is_some())))
+            }
             CommitTemplatePropertyKind::CommitList(property) => {
                 Some(Box::new(property.map(|l| !l.is_empty())))
             }
         match self {
             CommitTemplatePropertyKind::Core(property) => property.try_into_template(),
             CommitTemplatePropertyKind::Commit(_) => None,
+            CommitTemplatePropertyKind::CommitOpt(_) => None,
             CommitTemplatePropertyKind::CommitList(_) => None,
             CommitTemplatePropertyKind::RefName(property) => Some(property.into_template()),
             CommitTemplatePropertyKind::RefNameList(property) => Some(property.into_template()),

docs/templates.md+6−0

@@ -137,6 +137,12 @@ The following methods are defined. · 136 unmodified lines
137		137
138	* `.short([len: Integer]) -> String`	138	* `.short([len: Integer]) -> String`
139		139
		140	### Option type
		141
		142	An option can be implicitly converted to `Boolean` denoting whether the
		143	contained value is set. If set, all methods of the contained value can be
		144	invoked. If not set, an error will be reported inline on method call.
		145
140	### RefName type	146	### RefName type
141		147
142	The following methods are defined.	148	The following methods are defined.