1 files changed, 58 insertions, 0 deletions
diff --git a/chewed/src/error.rs b/chewed/src/error.rs
new file mode 100644
index 0000000..cb2cc4b
--- /dev/null
+++ b/chewed/src/error.rs
@@ -0,0 +1,58 @@
+use std::{error::Error, fmt};
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub enum TakeError {
+    BadBranch(char, &'static [char]),
+    BadString(String, &'static str),
+    EndOfStream,
+}
+
+impl fmt::Display for TakeError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::BadBranch(got, expected) => {
+                write!(f, "Unexpected character {:?}.", got)?;
+
+                if expected.is_empty() {
+                    write!(f, "Expected end of input.")
+                } else if expected.len() == 1 {
+                    write!(f, "Expected character {:?}.", expected[0])
+                } else {
+                    let mut iter = expected.iter();
+                    write!(f, "Expected one of {:?}", iter.next().unwrap())?;
+
+                    for c in iter {
+                        write!(f, ", {:?}", c)?;
+                    }
+
+                    Ok(())
+                }
+            }
+            Self::BadString(got, expected) => write!(f, "Unexpected string {:?}. Expected {:?}", got, expected),
+            Self::EndOfStream => write!(f, "Unexpected end of input"),
+        }
+    }
+}
+
+impl Error for TakeError {}
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub enum ParseError {
+    TakeError(TakeError),
+    InputContinues,
+}
+
+impl fmt::Display for ParseError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::TakeError(e) => e.fmt(f),
+            Self::InputContinues => write!(f, "Expected end of input"),
+        }
+    }
+}
+
+impl From<TakeError> for ParseError {
+    fn from(e: TakeError) -> Self {
+        Self::TakeError(e)
+    }
+}