write an eager parser

src/error.rs

@@ -14,4 +14,5 @@ pub enum IMFError<'a> {
     MessageIDList(nom::Err<nom::error::Error<&'a str>>),
     Unstructured(nom::Err<nom::error::Error<&'a str>>),
     PhraseList(nom::Err<nom::error::Error<&'a str>>),
+    ReceivedLog(nom::Err<nom::error::Error<&'a str>>),
 }

src/fragments/address.rs

@@ -14,40 +14,40 @@ use crate::fragments::misc_token::phrase;
 use crate::fragments::whitespace::{cfws};
 use crate::error::IMFError;
 
-impl<'a> TryFrom<lazy::Mailbox<'a>> for MailboxRef {
+impl<'a> TryFrom<&'a lazy::Mailbox<'a>> for MailboxRef {
     type Error = IMFError<'a>;
 
-    fn try_from(mx: lazy::Mailbox<'a>) -> Result<Self, Self::Error> {
+    fn try_from(mx: &'a lazy::Mailbox<'a>) -> Result<Self, Self::Error> {
         mailbox(mx.0)
             .map(|(_, m)| m)
             .map_err(|e| IMFError::Mailbox(e))
     }
 }
 
-impl<'a> TryFrom<lazy::MailboxList<'a>> for MailboxList {
+impl<'a> TryFrom<&'a lazy::MailboxList<'a>> for MailboxList {
     type Error = IMFError<'a>;
 
-    fn try_from(ml: lazy::MailboxList<'a>) -> Result<Self, Self::Error> {
+    fn try_from(ml: &'a lazy::MailboxList<'a>) -> Result<Self, Self::Error> {
         mailbox_list(ml.0)
             .map(|(_, m)| m)
             .map_err(|e| IMFError::MailboxList(e))
     }
 }
 
-impl<'a> TryFrom<lazy::AddressList<'a>> for AddressList {
+impl<'a> TryFrom<&'a lazy::AddressList<'a>> for AddressList {
     type Error = IMFError<'a>;
 
-    fn try_from(al: lazy::AddressList<'a>) -> Result<Self, Self::Error> {
+    fn try_from(al: &'a lazy::AddressList<'a>) -> Result<Self, Self::Error> {
         address_list(al.0)
             .map(|(_, a)| a)
             .map_err(|e| IMFError::AddressList(e))
     }
 }
 
-impl<'a> TryFrom<lazy::NullableAddressList<'a>> for AddressList {
+impl<'a> TryFrom<&'a lazy::NullableAddressList<'a>> for AddressList {
     type Error = IMFError<'a>;
 
-    fn try_from(nal: lazy::NullableAddressList<'a>) -> Result<Self, Self::Error> {
+    fn try_from(nal: &'a lazy::NullableAddressList<'a>) -> Result<Self, Self::Error> {
         opt(alt((address_list, address_list_cfws)))(nal.0)
             .map(|(_, a)| a.unwrap_or(vec![]))
             .map_err(|e| IMFError::NullableAddressList(e))

src/fragments/datetime.rs

@@ -18,10 +18,10 @@ use crate::error::IMFError;
 const MIN: i32 = 60;
 const HOUR: i32 = 60 * MIN;
 
-impl<'a> TryFrom<lazy::DateTime<'a>> for DateTime<FixedOffset> {
+impl<'a> TryFrom<&'a lazy::DateTime<'a>> for DateTime<FixedOffset> {
     type Error = IMFError<'a>;
 
-    fn try_from(value: lazy::DateTime<'a>) -> Result<Self, Self::Error> {
+    fn try_from(value: &'a lazy::DateTime<'a>) -> Result<Self, Self::Error> {
         match section(value.0) {
             Ok((_, Some(dt))) => Ok(dt),
             Err(e) => Err(IMFError::DateTimeParse(e)),

src/fragments/eager.rs

@@ -0,0 +1,72 @@
+use chrono::{DateTime, FixedOffset};
+use crate::fragments::model::{
+    MailboxList, MailboxRef, AddressList,
+    MessageId, MessageIdList};
+use crate::fragments::misc_token::{Unstructured, PhraseList};
+use crate::fragments::trace::ReceivedLog;
+use crate::fragments::lazy::Field as Lazy;
+use crate::error::IMFError;
+
+#[derive(Debug, PartialEq)]
+pub enum Field<'a> {
+    // 3.6.1.  The Origination Date Field
+    Date(DateTime<FixedOffset>),
+
+    // 3.6.2.  Originator Fields
+    From(MailboxList),
+    Sender(MailboxRef),
+    ReplyTo(AddressList),
+
+    // 3.6.3.  Destination Address Fields
+    To(AddressList),
+    Cc(AddressList),
+    Bcc(AddressList),
+
+    // 3.6.4.  Identification Fields
+    MessageID(MessageId<'a>),
+    InReplyTo(MessageIdList<'a>),
+    References(MessageIdList<'a>),
+
+    // 3.6.5.  Informational Fields
+    Subject(Unstructured),
+    Comments(Unstructured),
+    Keywords(PhraseList),
+
+    // 3.6.6   Resent Fields (not implemented)
+    // 3.6.7   Trace Fields
+    Received(ReceivedLog<'a>),
+    ReturnPath(MailboxRef),
+
+    // 3.6.8.  Optional Fields
+    Optional(&'a str, Unstructured),
+
+    // None
+    Rescue(&'a str),
+}
+use Field::*;
+
+impl<'a> TryFrom<&'a Lazy<'a>> for Field<'a> {
+    type Error = IMFError<'a>;
+
+    fn try_from(l: &'a Lazy<'a>) -> Result<Self, Self::Error> {
+        match l {
+            Lazy::Date(v) => v.try_into().map(|v| Date(v)),
+            Lazy::From(v) => v.try_into().map(|v| From(v)),
+            Lazy::Sender(v) => v.try_into().map(|v| Sender(v)),
+            Lazy::ReplyTo(v) => v.try_into().map(|v| ReplyTo(v)),
+            Lazy::To(v) => v.try_into().map(|v| To(v)),
+            Lazy::Cc(v) => v.try_into().map(|v| Cc(v)),
+            Lazy::Bcc(v) => v.try_into().map(|v| Bcc(v)),
+            Lazy::MessageID(v) => v.try_into().map(|v| MessageID(v)),
+            Lazy::InReplyTo(v) => v.try_into().map(|v| InReplyTo(v)),
+            Lazy::References(v) => v.try_into().map(|v| References(v)),
+            Lazy::Subject(v) => v.try_into().map(|v| Subject(v)),
+            Lazy::Comments(v) => v.try_into().map(|v| Comments(v)),
+            Lazy::Keywords(v) => v.try_into().map(|v| Keywords(v)),
+            Lazy::Received(v) => v.try_into().map(|v| Received(v)),
+            Lazy::ReturnPath(v) => v.try_into().map(|v| ReturnPath(v)),
+            Lazy::Optional(k, v) => v.try_into().map(|v| Optional(k, v)),
+            Lazy::Rescue(v) => Ok(Rescue(*v)),
+        }
+    }
+}

src/fragments/identification.rs

@@ -15,20 +15,20 @@ use crate::fragments::mailbox::is_dtext;
 use crate::fragments::model::{MessageId, MessageIdList};
 use crate::error::IMFError;
 
-impl<'a> TryFrom<lazy::Identifier<'a>> for MessageId<'a> {
+impl<'a> TryFrom<&'a lazy::Identifier<'a>> for MessageId<'a> {
     type Error = IMFError<'a>;
 
-    fn try_from(id: lazy::Identifier<'a>) -> Result<Self, Self::Error> {
+    fn try_from(id: &'a lazy::Identifier<'a>) -> Result<Self, Self::Error> {
         msg_id(id.0)
             .map(|(_, i)| i)
             .map_err(|e| IMFError::MessageID(e))
     }
 }
 
-impl<'a> TryFrom<lazy::IdentifierList<'a>> for MessageIdList<'a> {
+impl<'a> TryFrom<&'a lazy::IdentifierList<'a>> for MessageIdList<'a> {
     type Error = IMFError<'a>;
 
-    fn try_from(id: lazy::IdentifierList<'a>) -> Result<Self, Self::Error> {
+    fn try_from(id: &'a lazy::IdentifierList<'a>) -> Result<Self, Self::Error> {
         many1(msg_id)(id.0)
             .map(|(_, i)| i)
             .map_err(|e| IMFError::MessageIDList(e))

src/fragments/lazy.rs

@@ -71,7 +71,7 @@ pub enum Field<'a> {
     ReturnPath(Mailbox<'a>),
 
     // 3.6.8.  Optional Fields
-    Optional(&'a str, &'a str),
+    Optional(&'a str, Unstructured<'a>),
 
     // None
     Rescue(&'a str),
@@ -126,6 +126,6 @@ fn correct_field(input: &str) -> IResult<&str, Field> {
             "return-path" => ReturnPath(Mailbox(rest)),
             "received" => Received(ReceivedLog(rest)),
 
-            _ => Optional(name, rest),
+            _ => Optional(name, Unstructured(rest)),
     }))
 }

src/fragments/misc_token.rs

@@ -15,25 +15,28 @@ use crate::fragments::whitespace::{fws, is_obs_no_ws_ctl};
 use crate::fragments::words::{atom, is_vchar};
 use crate::error::IMFError;
 
-type Unstructured = String;
-type PhraseList = Vec<String>;
+#[derive(Debug, PartialEq)]
+pub struct Unstructured(pub String);
 
-impl<'a> TryFrom<lazy::Unstructured<'a>> for Unstructured {
+#[derive(Debug, PartialEq)]
+pub struct PhraseList(pub Vec<String>);
+
+impl<'a> TryFrom<&'a lazy::Unstructured<'a>> for Unstructured {
     type Error = IMFError<'a>;
 
-    fn try_from(input: lazy::Unstructured<'a>) -> Result<Self, Self::Error> {
+    fn try_from(input: &'a lazy::Unstructured<'a>) -> Result<Self, Self::Error> {
         unstructured(input.0)
-            .map(|(_, v)| v)
+            .map(|(_, v)| Unstructured(v))
             .map_err(|e| IMFError::Unstructured(e))
     } 
 }
 
-impl<'a> TryFrom<lazy::PhraseList<'a>> for PhraseList {
+impl<'a> TryFrom<&'a lazy::PhraseList<'a>> for PhraseList {
     type Error = IMFError<'a>;
 
-    fn try_from(p: lazy::PhraseList<'a>) -> Result<Self, Self::Error> {
+    fn try_from(p: &'a lazy::PhraseList<'a>) -> Result<Self, Self::Error> {
         separated_list1(tag(","), phrase)(p.0)
-            .map(|(_, q)| q)
+            .map(|(_, q)| PhraseList(q))
             .map_err(|e| IMFError::PhraseList(e))
     }
 }

src/fragments/mod.rs

@@ -14,6 +14,7 @@ mod identification;
 mod trace;
 mod datetime;
 pub mod lazy;
+pub mod eager;
 
 // Header blocks
 pub mod header;

src/fragments/trace.rs

@@ -8,7 +8,21 @@ use nom::{
     multi::many0,
     sequence::{delimited, pair, tuple},
 };
-use crate::fragments::{datetime, mailbox, model, misc_token, whitespace};
+use crate::fragments::{datetime, mailbox, model, misc_token, whitespace, lazy};
+use crate::error::IMFError;
+
+#[derive(Debug, PartialEq)]
+pub struct ReceivedLog<'a>(pub &'a str);
+
+impl<'a> TryFrom<&'a lazy::ReceivedLog<'a>> for ReceivedLog<'a> {
+    type Error = IMFError<'a>;
+
+    fn try_from(input: &'a lazy::ReceivedLog<'a>) -> Result<Self, Self::Error> {
+        received_body(input.0)
+            .map_err(|e| IMFError::ReceivedLog(e))
+            .map(|(_, v)| ReceivedLog(v))
+    }
+}
 
 pub fn received_body(input: &str) -> IResult<&str, &str> {
     map(

src/multipass/field_eager.rs

@@ -0,0 +1,63 @@
+use crate::fragments::eager;
+use crate::multipass::field_lazy;
+
+#[derive(Debug, PartialEq)]
+pub struct Parsed<'a> {
+    pub fields: Vec<eager::Field<'a>>,
+    pub body: &'a [u8],
+}
+
+impl<'a> From <&'a field_lazy::Parsed<'a>> for Parsed<'a> {
+    fn from(p: &'a field_lazy::Parsed<'a>) -> Self {
+        Parsed {
+            fields: p.fields.iter().filter_map(|entry| entry.try_into().ok()).collect(),
+            body: p.body,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::fragments::lazy;
+    use crate::fragments::model;
+    use chrono::{FixedOffset, TimeZone};
+
+    #[test]
+    fn test_field_name() {
+        assert_eq!(Parsed::from(&field_lazy::Parsed {
+            fields: vec![
+                lazy::Field::From(lazy::MailboxList("hello@world.com,\r\n\talice@wonderlands.com\r\n")),
+                lazy::Field::Date(lazy::DateTime("12 Mar 1997 07:33:25 Z\r\n")),
+            ],
+            body: b"Hello world!",
+        }),
+        Parsed {
+            fields: vec![
+                eager::Field::From(vec![
+                    model::MailboxRef { 
+                        name: None, 
+                        addrspec: model::AddrSpec { 
+                            local_part: "hello".into(), 
+                            domain: "world.com".into() 
+                        }
+                    }, 
+                    model::MailboxRef { 
+                        name: None, 
+                        addrspec: model::AddrSpec { 
+                            local_part: "alice".into(), 
+                            domain: "wonderlands.com".into() 
+                        }
+                    },
+                ]),
+                eager::Field::Date(
+                    FixedOffset::east_opt(0)
+                    .unwrap()
+                    .with_ymd_and_hms(1997, 03, 12, 7, 33, 25)
+                    .unwrap()
+                ),
+            ],
+            body: b"Hello world!",
+        });
+    }
+}

src/multipass/mod.rs

@@ -1,4 +1,5 @@
 pub mod segment;
 pub mod guess_charset;
 pub mod extract_fields;
-pub mod parse_field_lazy;
+pub mod field_lazy;
+pub mod field_eager;