mime part of rfc5322

src/rfc5322/mime.rs

@@ -0,0 +1,36 @@
+use nom::{
+    IResult,
+    sequence::tuple,
+    bytes::complete::{tag, take},
+    combinator::{map, opt, verify},
+};
+
+use crate::text::ascii;
+use crate::text::whitespace::cfws;
+
+#[derive(Debug, PartialEq)]
+pub struct Version {
+    pub major: u8,
+    pub minor: u8,
+}
+
+pub fn version(input: &[u8]) -> IResult<&[u8], Version> {
+    let (rest, (_, major, _, _, _, minor, _)) = tuple((
+        opt(cfws),
+        map(verify(take(1usize), is_digit), ascii_to_u8),
+        opt(cfws),
+        tag(b"."),
+        opt(cfws),
+        map(verify(take(1usize), is_digit), ascii_to_u8),
+        opt(cfws),
+    ))(input)?;
+    Ok((rest, Version { major, minor }))
+}
+
+fn is_digit(c: &[u8]) -> bool {
+    c[0] >= ascii::N0 && c[0] <= ascii::N9
+}
+
+fn ascii_to_u8(c: &[u8]) -> u8 {
+    c[0] - ascii::N0
+}

src/rfc5322/mod.rs

@@ -3,3 +3,4 @@ pub mod address;
 pub mod datetime;
 pub mod trace;
 pub mod identification;
+pub mod mime;