1 files changed, 133 insertions, 0 deletions
diff --git a/lib/domain/libimagtodo/src/iter.rs b/lib/domain/libimagtodo/src/iter.rs
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+++ b/lib/domain/libimagtodo/src/iter.rs
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+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015-2019 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use std::result::Result as RResult;
+
+use failure::Fallible as Result;
+use failure::Error;
+use filters::failable::filter::FailableFilter;
+
+use libimagstore::store::FileLockEntry;
+use libimagstore::store::Entry;
+
+use crate::entry::Todo;
+use crate::status::Status;
+use crate::priority::Priority;
+
+/// Iterator adaptor which filters an Iterator<Item = FileLockEntry> so that only todos are left
+pub struct OnlyTodos<'a>(Box<dyn Iterator<Item = FileLockEntry<'a>>>);
+
+impl<'a> OnlyTodos<'a> {
+    pub fn new(it: Box<dyn Iterator<Item = FileLockEntry<'a>>>) -> Self {
+        OnlyTodos(it)
+    }
+}
+
+impl<'a> Iterator for OnlyTodos<'a> {
+    type Item = Result<FileLockEntry<'a>>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while let Some(next) = self.0.next() {
+            match next.is_todo() {
+                Ok(true)  => return Some(Ok(next)),
+                Ok(false) => continue,
+                Err(e)    => return Some(Err(e)),
+            }
+        }
+
+        None
+    }
+}
+
+/// Helper filter type
+///
+/// Can be used to filter an Iterator<Item = FileLockEntry> of Todos by status
+///
+pub struct StatusFilter(Status);
+
+impl FailableFilter<Entry> for StatusFilter {
+    type Error = Error;
+
+    fn filter(&self, entry: &Entry) -> RResult<bool, Self::Error> {
+        Ok(entry.get_status()? == self.0)
+    }
+}
+
+/// Helper filter type
+///
+/// Can be used to filter an Iterator<Item = FileLockEntry> of Todos for scheduled todos
+///
+pub struct IsScheduledFilter;
+
+impl FailableFilter<Entry> for IsScheduledFilter {
+    type Error = Error;
+
+    fn filter(&self, entry: &Entry) -> RResult<bool, Self::Error> {
+        entry.get_scheduled().map(|s| s.is_some())
+    }
+}
+
+/// Helper filter type
+///
+/// Can be used to filter an Iterator<Item = FileLockEntry> of Todos for hidden todos
+///
+pub struct IsHiddenFilter;
+
+impl FailableFilter<Entry> for IsHiddenFilter {
+    type Error = Error;
+
+    fn filter(&self, entry: &Entry) -> RResult<bool, Self::Error> {
+        entry.get_hidden().map(|s| s.is_some())
+    }
+}
+
+
+/// Helper filter type
+///
+/// Can be used to filter an Iterator<Item = FileLockEntry> of Todos for due todos
+///
+pub struct IsDueFilter;
+
+impl FailableFilter<Entry> for IsDueFilter {
+    type Error = Error;
+
+    fn filter(&self, entry: &Entry) -> RResult<bool, Self::Error> {
+        entry.get_due().map(|s| s.is_some())
+    }
+}
+
+
+/// Helper filter type
+///
+/// Can be used to filter an Iterator<Item = FileLockEntry> of Todos for priority
+///
+/// # Warning
+///
+/// If no priority is set for the entry, this filters out the entry
+///
+pub struct PriorityFilter(Priority);
+
+impl FailableFilter<Entry> for PriorityFilter {
+    type Error = Error;
+
+    fn filter(&self, entry: &Entry) -> RResult<bool, Self::Error> {
+        Ok(entry.get_priority()?.map(|p| p == self.0).unwrap_or(false))
+    }
+}
+