feat(span): make span end optional

src/protocol.rs

@@ -102,8 +102,8 @@ pub struct SourceSpan {
     pub label: String,
     /// The start of the span.
     pub start: SourceLocation,
-    /// The end of the span.
-    pub end: SourceLocation,
+    /// The end of the span. Optional
+    pub end: Option<SourceLocation>,
 }
 
 /**

tests/reporter.rs

@@ -64,11 +64,7 @@ fn fancy() -> io::Result<()> {
                     column: 0,
                     offset: 0,
                 },
-                end: SourceLocation {
-                    line: 0,
-                    column: 4,
-                    offset: 4,
-                },
+                end: None,
             },
         }],
     };