Add tests for search option.

org_mode_samples/object/regular_link/code_ref_link.org

@@ -10,3 +10,4 @@ rem)]]
 # These become fuzzy
 [[(foo) ]]
 [[ (foo)]]
+[[(foo)::3]]

org_mode_samples/object/regular_link/custom_id_link.org

@@ -2,3 +2,5 @@
 
 [[#fo
 o]]
+
+[[#foo::3]]

org_mode_samples/object/regular_link/file_link.org

@@ -2,3 +2,15 @@
 
 [[file:simp
 le.org]]
+
+[[file:simple.org::3]]
+[[file:simple.org::foo]]
+[[file:simple.org::#foo]]
+[[file:simple.org::foo  bar]]
+[[file:simple.org::foo
+bar]]
+[[file:simple.org::foo  
+bar]]
+[[file:simple.org::foo  
+  bar]]
+[[file:simple.org::foo::bar]]

org_mode_samples/object/regular_link/fuzzy_link.org

@@ -2,3 +2,5 @@
 
 [[eli
 sp.org]]
+
+[[elisp.org::3]]

org_mode_samples/object/regular_link/id_link.org

@@ -2,3 +2,5 @@
 
 [[id:83986bdf-987c-465d
 -8851-44cb4c02a86c]]
+
+[[id:83986bdf-987c-465d-8851-44cb4c02a86c::foo]]

org_mode_samples/object/regular_link/protocol_link.org

@@ -2,3 +2,5 @@
 
 [[shell:fo
 o]]
+
+[[shell:foo::3]]

src/compare/diff.rs

@@ -2805,8 +2805,8 @@ fn compare_regular_link<'b, 's>(
         ),
         (
             EmacsField::Required(":search-option"),
-            compare_identity,
+            |r| r.search_option,
-            compare_property_always_nil
+            compare_property_quoted_string
         )
     )? {
         this_status = new_status;

src/parser/regular_link.rs

@@ -6,7 +6,9 @@ use nom::bytes::complete::take_until;
 use nom::character::complete::anychar;
 use nom::combinator::consumed;
 use nom::combinator::eof;
+use nom::combinator::map;
 use nom::combinator::map_parser;
+use nom::combinator::opt;
 use nom::combinator::peek;
 use nom::combinator::recognize;
 use nom::combinator::rest;
@@ -58,6 +60,7 @@ fn regular_link_without_description<'b, 'g, 'r, 's>(
             link_type: path.link_type,
             path: path.path,
             raw_link: path.raw_link,
+            search_option: path.search_option,
         },
     ))
 }
@@ -82,6 +85,7 @@ fn regular_link_with_description<'b, 'g, 'r, 's>(
             link_type: path.link_type,
             path: path.path,
             raw_link: path.raw_link,
+            search_option: path.search_option,
         },
     ))
 }
@@ -90,6 +94,7 @@ struct PathReg<'s> {
     link_type: LinkType<'s>,
     path: &'s str,
     raw_link: &'s str,
+    search_option: Option<&'s str>,
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
@@ -123,13 +128,20 @@ fn parse_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>> {
 }
 
 fn file_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>> {
-    let (remaining, (raw_link, (_, path))) = consumed(tuple((tag("file:"), rest)))(input)?;
+    let (remaining, (raw_link, (_, path, search_option))) = consumed(tuple((
+        tag("file:"),
+        recognize(many_till(anychar, alt((peek(tag("::")), eof)))),
+        opt(map(tuple((tag("::"), rest)), |(_, search_option)| {
+            search_option
+        })),
+    )))(input)?;
     Ok((
         remaining,
         PathReg {
             link_type: LinkType::File,
             path: path.into(),
             raw_link: raw_link.into(),
+            search_option: search_option.map(Into::<&str>::into),
         },
     ))
 }
@@ -142,6 +154,7 @@ fn id_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>> {
             link_type: LinkType::Id,
             path: path.into(),
             raw_link: raw_link.into(),
+            search_option: None,
         },
     ))
 }
@@ -154,6 +167,7 @@ fn custom_id_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s
             link_type: LinkType::CustomId,
             path: path.into(),
             raw_link: raw_link.into(),
+            search_option: None,
         },
     ))
 }
@@ -170,6 +184,7 @@ fn code_ref_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>
             link_type: LinkType::CodeRef,
             path: path.into(),
             raw_link: raw_link.into(),
+            search_option: None,
         },
     ))
 }
@@ -183,6 +198,7 @@ fn protocol_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>
             link_type: LinkType::Protocol(protocol.into()),
             path: path.into(),
             raw_link: raw_link.into(),
+            search_option: None,
         },
     ))
 }
@@ -195,6 +211,7 @@ fn fuzzy_path_reg<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PathReg<'s>> {
             link_type: LinkType::Fuzzy,
             path: body.into(),
             raw_link: body.into(),
+            search_option: None,
         },
     ))
 }

src/types/object.rs

@@ -80,6 +80,7 @@ pub struct RegularLink<'s> {
     pub link_type: LinkType<'s>,
     pub path: &'s str,
     pub raw_link: &'s str,
+    pub search_option: Option<&'s str>,
 }
 
 #[derive(Debug, PartialEq)]