change how mechanism work

src/mime/mechanism.rs

@@ -9,7 +9,7 @@ use crate::text::whitespace::cfws;
 use crate::text::words::mime_token as token;
 
 #[derive(Debug, Clone, PartialEq)]
-pub enum Mechanism<'a> {
+pub enum DecodedMechanism<'a> {
     _7Bit,
     _8Bit,
     Binary,
@@ -18,23 +18,23 @@ pub enum Mechanism<'a> {
     Other(&'a [u8]),
 }
 
-pub fn mechanism(input: &[u8]) -> IResult<&[u8], Mechanism> {
-    use Mechanism::*;
+pub struct Mechanism<'a>(pub &'a [u8]);
+impl<'a> Mechanism<'a> {
+    pub fn decode(&self) -> DecodedMechanism {
+        use DecodedMechanism::*;
+        match self.0.to_ascii_lowercase().as_slice() {
+            b"7bit" => _7Bit,
+            b"8bit" => _8Bit,
+            b"binary" => Binary,
+            b"quoted-printable" => QuotedPrintable,
+            b"base64" => Base64,
+            _ => Other(self.0),
+        }
+    }
+}
 
-    alt((
-        delimited(
-            opt(cfws),
-            alt(( 
-                value(_7Bit, tag_no_case("7bit")),
-                value(_8Bit, tag_no_case("8bit")),
-                value(Binary, tag_no_case("binary")),
-                value(QuotedPrintable, tag_no_case("quoted-printable")),
-                value(Base64, tag_no_case("base64")),
-            )),
-            opt(cfws),
-        ),
-        map(token, Other),
-    ))(input)
+pub fn mechanism(input: &[u8]) -> IResult<&[u8], Mechanism> {
+    map(token, Mechanism)(input)
 }
 
 
@@ -44,28 +44,28 @@ mod tests {
     #[test]
     fn test_mechanism() {
         assert_eq!(
-            mechanism(b"7bit"),
-            Ok((&b""[..], Mechanism::_7Bit)),
+            mechanism(b"7bit").unwrap().1.decode(),
+            DecodedMechanism::_7Bit,
         );
 
         assert_eq!(
-            mechanism(b"(youhou) 8bit"),
-            Ok((&b""[..], Mechanism::_8Bit)),
+            mechanism(b"(youhou) 8bit").unwrap().1.decode(),
+            DecodedMechanism::_8Bit,
         );
         
         assert_eq!(
-            mechanism(b"(blip) bInArY (blip blip)"),
-            Ok((&b""[..], Mechanism::Binary)),
+            mechanism(b"(blip) bInArY (blip blip)").unwrap().1.decode(),
+            DecodedMechanism::Binary,
         );
 
         assert_eq!(
-            mechanism(b" base64 "),
-            Ok((&b""[..], Mechanism::Base64)),
+            mechanism(b" base64 ").unwrap().1.decode(),
+            DecodedMechanism::Base64,
         );
 
         assert_eq!(
-            mechanism(b" Quoted-Printable "),
-            Ok((&b""[..], Mechanism::QuotedPrintable)),
+            mechanism(b" Quoted-Printable ").unwrap().1.decode(),
+            DecodedMechanism::QuotedPrintable,
         );
     }
 }