1 files changed, 46 insertions, 0 deletions
diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs
index 4e56264..4e183b4 100644
--- a/dhall/src/lib.rs
+++ b/dhall/src/lib.rs
@@ -6,3 +6,49 @@ mod normalize;
 pub use crate::normalize::*;
 pub mod imports;
 pub mod typecheck;
+
+use dhall_core::*;
+use std::fs::File;
+use std::io::Read;
+use std::path::Path;
+use std::fmt;
+
+#[derive(Debug)]
+pub enum DhallError {
+    ParseError(parser::ParseError),
+    IOError(std::io::Error),
+}
+impl From<parser::ParseError> for DhallError {
+    fn from(e: parser::ParseError) -> Self {
+        DhallError::ParseError(e)
+    }
+}
+impl From<std::io::Error> for DhallError {
+    fn from(e: std::io::Error) -> Self {
+        DhallError::IOError(e)
+    }
+}
+impl fmt::Display for DhallError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        use self::DhallError::*;
+        match self {
+            ParseError(e) => e.fmt(f),
+            IOError(e) => e.fmt(f),
+        }
+    }
+}
+
+/// `source_pool` is a Vec of strings to be used to store the contents of imported files.
+/// No ideal but necessary for lifetime reasons for now.
+pub fn load_dhall_file<'i, 'a: 'i>(
+    f: &Path,
+    source_pool: &'a mut Vec<String>,
+    resolve_imports: bool,
+) -> Result<Expr<'i, X, X>, DhallError> {
+    source_pool.push(String::new());
+    let mut buffer = source_pool.last_mut().unwrap();
+    File::open(f)?.read_to_string(&mut buffer)?;
+    let expr = parser::parse_expr(&*buffer)?;
+    let expr = imports::resolve_imports(&expr);
+    Ok(expr)
+}