add a charset detector

Cargo.lock

@@ -41,6 +41,17 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chardetng"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "14b8f0b65b7b08ae3c8187e8d77174de20cb6777864c6b832d8ad365999cf1ea"
+dependencies = [
+ "cfg-if",
+ "encoding_rs",
+ "memchr",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.26"
@@ -62,6 +73,15 @@ version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
 
+[[package]]
+name = "encoding_rs"
+version = "0.8.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071a31f4ee85403370b58aca746f01041ede6f0da2730960ad001edc2b71b394"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.57"
@@ -89,7 +109,9 @@ dependencies = [
 name = "imf-codec"
 version = "0.1.0"
 dependencies = [
+ "chardetng",
  "chrono",
+ "encoding_rs",
  "nom",
  "walkdir",
 ]

Cargo.toml

@@ -18,6 +18,8 @@ path = "src/parse.rs"
 [dependencies]
 nom = "7"
 chrono = "0.4"
+chardetng = "0.1"
+encoding_rs = "0.8"
 
 [dev-dependencies]
 walkdir = "2"

src/mailbox.rs

@@ -111,16 +111,13 @@ fn strict_local_part(input: &str) -> IResult<&str, String> {
 /// obs_local_part.
 ///
 /// ```abnf
-/// obs-local-part  =   word *(1*"." word)
+/// obs-local-part  =  *(*"." word)
 /// ```
 fn obs_local_part(input: &str) -> IResult<&str, String> {
-    map(pair(
-        word, 
-        fold_many0(
-            pair(is_a("."), word),
-            String::new,
-            |acc, (dots, txt)| acc + dots + &txt),
-    ), |(head, rest)| head.into_owned() + &rest)(input)
+    fold_many0(
+        pair(opt(is_a(".")), word),
+        String::new,
+        |acc, (dots, txt)| acc + dots.unwrap_or("") + &txt)(input)
 }
 
 /// Domain
@@ -295,4 +292,15 @@ mod tests {
             }))
         );
     }
+
+    #[test]
+    fn test_enron2() {
+        assert_eq!(
+            addr_spec(".nelson@enron.com"),
+            Ok(("", AddrSpec {
+                local_part: ".nelson".into(),
+                domain: "enron.com".into(),
+            }))
+        );
+    }
 }

src/parse.rs

@@ -2,9 +2,22 @@ use imf_codec::header;
 use std::io;
 use std::io::Read;
 
+use chardetng::EncodingDetector;
+use encoding_rs::Encoding;
+
 fn main() {
-    let mut email = String::new();
-    io::stdin().lock().read_to_string(&mut email).unwrap();
+    // Read full mail in memory
+    let mut rawmail = Vec::new();
+    io::stdin().lock().read_to_end(&mut rawmail).unwrap();
+
+    // Create detector
+    let mut detector = EncodingDetector::new();
+    detector.feed(&rawmail, true);
+    
+    // Get encoding
+    let enc: &Encoding = detector.guess(None, true);
+    let (email, encoding, malformed) = enc.decode(&rawmail);
+    println!("Encoding: {:?}, Malformed: {:?}", encoding, malformed);
 
     let (_, hdrs) = header::section(&email).unwrap();
     assert!(hdrs.date.is_some());