Move Span definition to its own file

And prepare for more variants

3 files changed, 46 insertions, 35 deletions

diff --git a/dhall_syntax/src/core/expr.rs b/dhall_syntax/src/core/expr.rs
index 2ad3ba8..70ce1dc 100644
--- a/dhall_syntax/src/core/expr.rs
+++ b/dhall_syntax/src/core/expr.rs
@@ -1,4 +1,3 @@
-use std::rc::Rc;
 
 use crate::map::{DupTreeMap, DupTreeSet};
 use crate::visitor::{self, ExprFMutVisitor, ExprFVisitor};
@@ -15,40 +14,6 @@ pub fn trivial_result<T>(x: Result<T, !>) -> T {
     }
 }
 
-/// A location in the source text
-#[derive(Debug, Clone)]
-pub struct Span {
-    input: Rc<str>,
-    /// # Safety
-    ///
-    /// Must be a valid character boundary index into `input`.
-    start: usize,
-    /// # Safety
-    ///
-    /// Must be a valid character boundary index into `input`.
-    end: usize,
-}
-
-impl Span {
-    pub(crate) fn make(input: Rc<str>, sp: pest::Span) -> Self {
-        Span {
-            input,
-            start: sp.start(),
-            end: sp.end(),
-        }
-    }
-    /// Takes the union of the two spans. Assumes that the spans come from the same input.
-    /// This will also capture any input between the spans.
-    pub fn union(&self, other: &Span) -> Self {
-        use std::cmp::{max, min};
-        Span {
-            input: self.input.clone(),
-            start: min(self.start, other.start),
-            end: max(self.start, other.start),
-        }
-    }
-}
-
 /// Double with bitwise equality
 #[derive(Debug, Copy, Clone)]
 pub struct NaiveDouble(f64);
diff --git a/dhall_syntax/src/core/mod.rs b/dhall_syntax/src/core/mod.rs
index fe2c0be..66bf229 100644
--- a/dhall_syntax/src/core/mod.rs
+++ b/dhall_syntax/src/core/mod.rs
@@ -4,6 +4,8 @@ mod import;
 pub use import::*;
 mod label;
 pub use label::*;
+mod span;
+pub use span::*;
 mod text;
 pub use text::*;
 pub mod context;
diff --git a/dhall_syntax/src/core/span.rs b/dhall_syntax/src/core/span.rs
new file mode 100644
index 0000000..ad5a3a9
--- /dev/null
+++ b/dhall_syntax/src/core/span.rs
@@ -0,0 +1,44 @@
+use std::rc::Rc;
+
+/// A location in the source text
+#[derive(Debug, Clone)]
+pub struct ParsedSpan {
+    input: Rc<str>,
+    /// # Safety
+    ///
+    /// Must be a valid character boundary index into `input`.
+    start: usize,
+    /// # Safety
+    ///
+    /// Must be a valid character boundary index into `input`.
+    end: usize,
+}
+
+/// A location in the source text
+#[derive(Debug, Clone)]
+pub enum Span {
+    Parsed(ParsedSpan),
+}
+
+impl Span {
+    pub(crate) fn make(input: Rc<str>, sp: pest::Span) -> Self {
+        Span::Parsed(ParsedSpan {
+            input,
+            start: sp.start(),
+            end: sp.end(),
+        })
+    }
+    /// Takes the union of the two spans. Assumes that the spans come from the same input.
+    /// This will also capture any input between the spans.
+    pub fn union(&self, other: &Span) -> Self {
+        use std::cmp::{max, min};
+        use Span::*;
+        match (self, other) {
+            (Parsed(x), Parsed(y)) => Span::Parsed(ParsedSpan {
+                input: x.input.clone(),
+                start: min(x.start, y.start),
+                end: max(x.start, y.start),
+            }),
+        }
+    }
+}