Implement --range

src/eval.rs

@@ -1,10 +1,14 @@
+use chrono::NaiveDate;
+
+use crate::files::arguments::{Range, RangeDate};
 use crate::files::Files;
 
 use self::command::CommandState;
 pub use self::date::Dates;
+use self::delta::Delta;
 use self::entry::Entries;
 pub use self::entry::{Entry, EntryKind, EntryMode};
-pub use self::error::{Error, Result};
+pub use self::error::{Error, Result, SourceInfo};
 pub use self::range::DateRange;
 
 mod command;
@@ -26,3 +30,32 @@ impl Files {
         Ok(entries.entries())
     }
 }
+
+impl Range {
+    pub fn eval(&self, index: usize, today: NaiveDate) -> Result<DateRange> {
+        let mut start = match self.start {
+            RangeDate::Date(d) => d,
+            RangeDate::Today => today,
+        };
+
+        if let Some(delta) = &self.start_delta {
+            let delta: Delta = delta.into();
+            start = delta.apply_date(index, start)?;
+        }
+
+        let mut end = start;
+
+        match self.end {
+            Some(RangeDate::Date(d)) => end = d,
+            Some(RangeDate::Today) => end = today,
+            None => {}
+        }
+
+        if let Some(delta) = &self.end_delta {
+            let delta: Delta = delta.into();
+            end = delta.apply_date(index, end)?;
+        }
+
+        Ok(DateRange::new(start, end))
+    }
+}