oops

1 files changed, 92 insertions, 0 deletions

diff --git a/dhall_core/src/text.rs b/dhall_core/src/text.rs
new file mode 100644
index 0000000..cd5fef3
--- /dev/null
+++ b/dhall_core/src/text.rs
@@ -0,0 +1,92 @@
+use crate::*;
+use std::iter::FromIterator;
+use std::ops::Add;
+use std::rc::Rc;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct InterpolatedText<Note, Embed> {
+    head: String,
+    tail: Vec<(Rc<Expr<Note, Embed>>, String)>,
+}
+
+impl<N, E> From<(String, Vec<(Rc<Expr<N, E>>, String)>)>
+    for InterpolatedText<N, E>
+{
+    fn from(x: (String, Vec<(Rc<Expr<N, E>>, String)>)) -> Self {
+        InterpolatedText {
+            head: x.0,
+            tail: x.1,
+        }
+    }
+}
+
+impl<N, E> From<String> for InterpolatedText<N, E> {
+    fn from(s: String) -> Self {
+        InterpolatedText {
+            head: s,
+            tail: vec![],
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum InterpolatedTextContents<'a, Note, Embed> {
+    Text(&'a str),
+    Expr(SubExpr<Note, Embed>),
+}
+
+impl<N, E> InterpolatedText<N, E> {
+    pub fn map<N2, E2, F>(&self, mut f: F) -> InterpolatedText<N2, E2>
+    where
+        F: FnMut(&Rc<Expr<N, E>>) -> Rc<Expr<N2, E2>>,
+    {
+        InterpolatedText {
+            head: self.head.clone(),
+            tail: self.tail.iter().map(|(e, s)| (f(e), s.clone())).collect(),
+        }
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = InterpolatedTextContents<N, E>> {
+        use std::iter::once;
+        once(InterpolatedTextContents::Text(self.head.as_ref())).chain(
+            self.tail.iter().flat_map(|(e, s)| {
+                once(InterpolatedTextContents::Expr(Rc::clone(e)))
+                    .chain(once(InterpolatedTextContents::Text(s)))
+            }),
+        )
+    }
+}
+
+impl<'a, N: 'a, E: 'a> FromIterator<InterpolatedTextContents<'a, N, E>>
+    for InterpolatedText<N, E>
+{
+    fn from_iter<T>(iter: T) -> Self
+    where
+        T: IntoIterator<Item = InterpolatedTextContents<'a, N, E>>,
+    {
+        let mut res = InterpolatedText {
+            head: "".to_owned(),
+            tail: vec![],
+        };
+        // let mut empty_string = "".to_owned();
+        let mut crnt_str = &mut res.head;
+        for x in iter.into_iter() {
+            match x {
+                InterpolatedTextContents::Text(s) => crnt_str.push_str(s),
+                InterpolatedTextContents::Expr(e) => {
+                    // crnt_str = &mut empty_string;
+                    res.tail.push((e.clone(), "".to_owned()));
+                    crnt_str = &mut res.tail.last_mut().unwrap().1;
+                }
+            }
+        }
+        res
+    }
+}
+
+impl<N, E> Add for &InterpolatedText<N, E> {
+    type Output = InterpolatedText<N, E>;
+    fn add(self, rhs: &InterpolatedText<N, E>) -> Self::Output {
+        self.iter().chain(rhs.iter()).collect()
+    }
+}