process tar files

Process tar files: BlockReader can read from .tar files.

Re-arrange ProcessPathResult::FILE_VALID arguments for consistency.

Cargo.toml

@@ -37,7 +37,8 @@ rand = "0.8.5"
 rangemap = "1.0.3"
 regex = "1.5.6"
 static_assertions = "1.1.0"
-tempfile = "3.3.0"
+tar = "0.4.38"
+tempfile = "3.3.0"   # TODO this could be moved to dev-dependencies
 termcolor = "1.1.3"
 unicode-width = "0.1.9"
 unroll = "0.1.5"

src/Data/datetime.rs

@@ -1,4 +1,11 @@
 // Data/datetime.rs
+//
+// the most relevant documents to understand this file:
+// `chrono` crate `strftime` format:
+// https://docs.rs/chrono/latest/chrono/format/strftime/index.html
+// `regex` crate patterns
+// https://docs.rs/regex/latest/regex/
+//
 
 #![allow(non_camel_case_types)]
 #![allow(non_upper_case_globals)]