progress

grep/src/lib.rs

@@ -4,6 +4,7 @@ extern crate regex_syntax as syntax;
 
 use std::error;
 use std::fmt;
+use std::io;
 use std::result;
 
 pub use search::{Grep, GrepBuilder};
@@ -26,6 +27,13 @@ pub enum Error {
     /// pattern. For example, if the line terminator is `\n` and the regex
     /// pattern is `\w+\n\w+`, then the presence of `\n` will cause this error.
     LiteralNotAllowed(char),
+    /// This errors occurs when a line exceeds the buffer size. The buffer
+    /// size is given.
+    LineTooLong(usize),
+    /// An IO error occurred while searching.
+    Io(io::Error),
+    /// An unused enum variant that indicates this enum may be expanded in
+    /// the future and therefore should not be exhaustively matched.
     #[doc(hidden)]
     __Nonexhaustive,
 }
@@ -35,6 +43,8 @@ impl error::Error for Error {
         match *self {
             Error::Regex(ref err) => err.description(),
             Error::LiteralNotAllowed(_) => "use of forbidden literal",
+            Error::LineTooLong(_) => "line exceeds buffer size",
+            Error::Io(ref err) => err.description(),
             Error::__Nonexhaustive => unreachable!(),
         }
     }
@@ -42,6 +52,7 @@ impl error::Error for Error {
     fn cause(&self) -> Option<&error::Error> {
         match *self {
             Error::Regex(ref err) => err.cause(),
+            Error::Io(ref err) => err.cause(),
             _ => None,
         }
     }
@@ -54,6 +65,11 @@ impl fmt::Display for Error {
             Error::LiteralNotAllowed(chr) => {
                 write!(f, "Literal '{}' not allowed.", chr)
             }
+            Error::LineTooLong(limit) => {
+                write!(f, "Line exceeded buffer size of {} bytes, try \
+                           searching with memory maps instead.", limit)
+            }
+            Error::Io(ref err) => err.fmt(f),
             Error::__Nonexhaustive => unreachable!(),
         }
     }
@@ -70,3 +86,9 @@ impl From<syntax::Error> for Error {
         Error::Regex(regex::Error::Syntax(err))
     }
 }
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        Error::Io(err)
+    }
+}