xso: use values instead of types for text codecs

This allows stateful or configurable codecs without having to express
all configuration in the type name itself. For example, we could have a
Base64 type with configurable Base64 engines without having to duplicate
the Base64 type itself.

(Note that the different engines in the Base64 crate are values, not
types.)

parsers/src/avatar.rs

@@ -5,7 +5,7 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 use xso::{
-    text::{Base64, StripWhitespace},
+    text::{Base64, StripWhitespace, TextCodec},
     AsXml, FromXml,
 };
 
@@ -58,7 +58,7 @@ pub struct Info {
 #[xml(namespace = ns::AVATAR_DATA, name = "data")]
 pub struct Data {
     /// Vector of bytes representing the avatar’s image.
-    #[xml(text(codec = Base64<StripWhitespace>))]
+    #[xml(text(codec = Base64.filtered(StripWhitespace)))]
     pub data: Vec<u8>,
 }
 

parsers/src/component.rs

@@ -20,7 +20,7 @@ pub struct Handshake {
     ///
     /// If None, it is the successful reply from the server, the stream is now
     /// fully established and both sides can now exchange stanzas.
-    #[xml(text(codec = FixedHex<20>))]
+    #[xml(text(codec = FixedHex::<20>))]
     pub data: Option<[u8; 20]>,
 }
 

parsers/src/vcard.rs

@@ -15,7 +15,7 @@
 
 use xso::{
     error::Error,
-    text::{Base64, StripWhitespace},
+    text::{Base64, StripWhitespace, TextCodec},
     AsXml, FromXml,
 };
 
@@ -50,7 +50,7 @@ pub struct Type {
 #[xml(namespace = ns::VCARD, name = "BINVAL")]
 pub struct Binval {
     /// The actual data.
-    #[xml(text(codec = Base64<StripWhitespace>))]
+    #[xml(text(codec = Base64.filtered(StripWhitespace)))]
     pub data: Vec<u8>,
 }
 

parsers/src/vcard_update.rs

@@ -30,7 +30,7 @@ pub struct VCardUpdate {
 #[xml(namespace = ns::VCARD_UPDATE, name = "photo")]
 pub struct Photo {
     /// The SHA1 hash of the avatar. Empty when there is no photo.
-    #[xml(text(codec = FixedHex<20>))]
+    #[xml(text(codec = FixedHex::<20>))]
     pub data: Option<[u8; 20]>,
 }