add some cli parsing stuff

src/cli/mod.rs

@@ -0,0 +1 @@
+mod lexer;

src/lib.rs

@@ -5,6 +5,7 @@
 #[macro_use]
 extern crate failure;
 
+mod cli;
 mod errors;
 mod operation;
 mod replica;
@@ -13,6 +14,7 @@ mod task;
 mod taskdb;
 pub mod taskstorage;
 mod tdb2;
+mod util;
 
 pub use operation::Operation;
 pub use replica::Replica;

src/tdb2/ff4.rs

@@ -1,7 +1,7 @@
 use std::str;
 
-use super::pig::Pig;
 use crate::task::{Task, TaskBuilder};
+use crate::util::pig::Pig;
 use failure::Fallible;
 
 /// Rust implementation of part of utf8_codepoint from Taskwarrior's src/utf8.cpp

src/tdb2/mod.rs

@@ -2,7 +2,6 @@
 //! support for the data structure as a  compatibility layer.
 
 mod ff4;
-mod pig;
 
 use self::ff4::parse_ff4;
 use crate::task::Task;

src/util/datetime.rs

@@ -0,0 +1,39 @@
+//! A re-implementation of the "Datetime" parsing utility from the Taskwarrior
+//! source.
+
+// TODO: this module is not yet implemented
+
+pub(crate) struct DateTime {}
+
+impl DateTime {
+    /// Parse a datestamp from a prefix of input and return the number of bytes consumed in the
+    /// input
+    pub(crate) fn parse<S: AsRef<str>>(
+        input: S,
+        format: &'static str,
+    ) -> Option<(DateTime, usize)> {
+        let input = input.as_ref();
+        let mut len = input.len();
+
+        // try parsing the whole string and repeatedly drop suffixes until a match
+        while len > 0 {
+            if let Some(str) = input.get(..len) {
+                match str {
+                    "2015" => return Some((DateTime {}, len)),
+                    "2015-" => return Some((DateTime {}, len)),
+                    "9th" => return Some((DateTime {}, len)),
+                    "10th" => return Some((DateTime {}, len)),
+                    "2015-W01" => return Some((DateTime {}, len)),
+                    "2015-02-17" => return Some((DateTime {}, len)),
+                    "2013-11-29T22:58:00Z" => return Some((DateTime {}, len)),
+                    "315532800" => return Some((DateTime {}, len)),
+                    "20131129T225800Z" => return Some((DateTime {}, len)),
+                    "today" => return Some((DateTime {}, len)),
+                    _ => (),
+                }
+            }
+            len -= 1;
+        }
+        None
+    }
+}

src/util/duration.rs

@@ -0,0 +1,44 @@
+//! A re-implementation of the "Duration" parsing utility from the Taskwarrior
+//! source.
+
+// TODO: this module is not yet implemented
+
+pub(crate) struct Duration {}
+
+impl Duration {
+    /// Parse a duration from a prefix of input and return the number of bytes consumed in the
+    /// input
+    pub(crate) fn parse<S: AsRef<str>>(
+        input: S,
+        format: &'static str,
+    ) -> Option<(Duration, usize)> {
+        let input = input.as_ref();
+        let mut len = input.len();
+
+        // try parsing the whole string and repeatedly drop suffixes until a match
+        while len > 0 {
+            if let Some(str) = input.get(..len) {
+                match str {
+                    "1w" => return Some((Duration {}, len)),
+                    "4w" => return Some((Duration {}, len)),
+                    "4weeks" => return Some((Duration {}, len)),
+                    "5mo" => return Some((Duration {}, len)),
+                    "6 years" => return Some((Duration {}, len)),
+                    "3 days" => return Some((Duration {}, len)),
+                    "1minute" => return Some((Duration {}, len)),
+                    "2hour" => return Some((Duration {}, len)),
+                    "1s" => return Some((Duration {}, len)),
+                    "1second" => return Some((Duration {}, len)),
+                    "PT23H" => return Some((Duration {}, len)),
+                    "PT1H" => return Some((Duration {}, len)),
+                    "P1Y" => return Some((Duration {}, len)),
+                    "P1Y1M1DT1H1M1S" => return Some((Duration {}, len)),
+                    "year" => return Some((Duration {}, len)),
+                    _ => (),
+                }
+            }
+            len -= 1;
+        }
+        None
+    }
+}

src/util/mod.rs

@@ -0,0 +1,3 @@
+pub(crate) mod datetime;
+pub(crate) mod duration;
+pub(crate) mod pig;

src/util/pig.rs

@@ -3,7 +3,7 @@
 
 use failure::Fallible;
 
-pub struct Pig<'a> {
+pub(crate) struct Pig<'a> {
     input: &'a [u8],
     cursor: usize,
 }