Add ability to convert context errors to generic errors

src/ctx/reason.rs

@@ -1,4 +1,4 @@
-use std::error::Error;
+use crate::err::Error;
 use std::fmt;
 use std::io;
 
@@ -8,8 +8,6 @@ pub enum Reason {
 	Canceled,
 }
 
-impl Error for Reason {}
-
 impl fmt::Display for Reason {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		match *self {
@@ -19,6 +17,15 @@ impl fmt::Display for Reason {
 	}
 }
 
+impl From<Reason> for Error {
+	fn from(reason: Reason) -> Error {
+		match reason {
+			Reason::Timedout => Error::TimeoutError,
+			Reason::Canceled => Error::CancelledError,
+		}
+	}
+}
+
 impl From<Reason> for io::Error {
 	fn from(reason: Reason) -> Self {
 		let kind = match reason {

src/err/mod.rs

@@ -15,6 +15,12 @@ pub enum Error {
 	#[error("Specify some SQL code to execute")]
 	EmptyError,
 
+	#[error("The query failed to complete in time")]
+	TimeoutError,
+
+	#[error("The query was cancelled before completion")]
+	CancelledError,
+
 	#[error("Parse error at position {pos} when parsing '{sql}'")]
 	ParseError {
 		pos: usize,