Big folder refactor

crates/util/unexpected/src/lib.rs

@@ -0,0 +1,74 @@
+// Copyright 2015-2020 Parity Technologies (UK) Ltd.
+// This file is part of OpenEthereum.
+
+// OpenEthereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// OpenEthereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Error utils
+
+use std::fmt;
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+/// Error indicating an expected value was not found.
+pub struct Mismatch<T> {
+    /// Value expected.
+    pub expected: T,
+    /// Value found.
+    pub found: T,
+}
+
+impl<T: fmt::Display> fmt::Display for Mismatch<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_fmt(format_args!(
+            "Expected {}, found {}",
+            self.expected, self.found
+        ))
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+/// Error indicating value found is outside of a valid range.
+pub struct OutOfBounds<T> {
+    /// Minimum allowed value.
+    pub min: Option<T>,
+    /// Maximum allowed value.
+    pub max: Option<T>,
+    /// Value found.
+    pub found: T,
+}
+
+impl<T> OutOfBounds<T> {
+    pub fn map<F, U>(self, map: F) -> OutOfBounds<U>
+    where
+        F: Fn(T) -> U,
+    {
+        OutOfBounds {
+            min: self.min.map(&map),
+            max: self.max.map(&map),
+            found: map(self.found),
+        }
+    }
+}
+
+impl<T: fmt::Display> fmt::Display for OutOfBounds<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let msg = match (self.min.as_ref(), self.max.as_ref()) {
+            (Some(min), Some(max)) => format!("Min={}, Max={}", min, max),
+            (Some(min), _) => format!("Min={}", min),
+            (_, Some(max)) => format!("Max={}", max),
+            (None, None) => "".into(),
+        };
+
+        f.write_fmt(format_args!("Value {} out of bounds. {}", self.found, msg))
+    }
+}