feat(core/rust): some useful traits for TString

string equality comparison and SkipPrefix

core/embed/rust/src/strutil.rs

@@ -93,13 +93,20 @@ pub enum TString<'a> {
     #[cfg(feature = "micropython")]
     Allocated(StrBuffer),
     #[cfg(feature = "translations")]
-    Translation(TR),
+    Translation {
+        tr: TR,
+        offset: u16,
+    },
     Str(&'a str),
 }
 
 impl TString<'_> {
+    pub fn len(&self) -> usize {
+        self.map(|s| s.len())
+    }
+
     pub fn is_empty(&self) -> bool {
-        self.map(|s| s.is_empty())
+        self.len() == 0
     }
 
     /// Maps the string to a value using a closure.
@@ -118,7 +125,7 @@ impl TString<'_> {
             #[cfg(feature = "micropython")]
             Self::Allocated(buf) => fun(buf.as_ref()),
             #[cfg(feature = "translations")]
-            Self::Translation(tr) => tr.map_translated(fun),
+            Self::Translation { tr, offset } => tr.map_translated(|s| fun(&s[*offset as usize..])),
             Self::Str(s) => fun(s),
         }
     }
@@ -127,7 +134,7 @@ impl TString<'_> {
 impl TString<'static> {
     #[cfg(feature = "translations")]
     pub const fn from_translation(tr: TR) -> Self {
-        Self::Translation(tr)
+        Self::Translation { tr, offset: 0 }
     }
 
     #[cfg(feature = "micropython")]
@@ -183,3 +190,30 @@ impl<'a> TryFrom<TString<'a>> for Obj {
         s.map(|t| t.try_into())
     }
 }
+
+impl<'a, 'b> PartialEq<TString<'a>> for TString<'b> {
+    fn eq(&self, other: &TString<'a>) -> bool {
+        self.map(|s| other.map(|o| s == o))
+    }
+}
+
+impl Eq for TString<'_> {}
+
+impl SkipPrefix for TString<'_> {
+    fn skip_prefix(&self, skip_bytes: usize) -> Self {
+        self.map(|s| {
+            assert!(skip_bytes <= s.len());
+            assert!(s.is_char_boundary(skip_bytes));
+        });
+        match self {
+            #[cfg(feature = "micropython")]
+            Self::Allocated(s) => Self::Allocated(s.skip_prefix(skip_bytes)),
+            #[cfg(feature = "translations")]
+            Self::Translation { tr, offset } => Self::Translation {
+                tr: *tr,
+                offset: offset + skip_bytes as u16,
+            },
+            Self::Str(s) => Self::Str(&s[skip_bytes..]),
+        }
+    }
+}

core/embed/rust/src/translations/generated/translated_string.rs

@@ -6,7 +6,7 @@
 #[cfg(feature = "micropython")]
 use crate::micropython::qstr::Qstr;
 
-#[derive(Debug, Copy, Clone, FromPrimitive)]
+#[derive(Debug, Copy, Clone, FromPrimitive, PartialEq, Eq)]
 #[repr(u16)]
 #[allow(non_camel_case_types)]
 pub enum TranslatedString {

core/embed/rust/src/translations/generated/translated_string.rs.mako

@@ -35,7 +35,7 @@ en_data = json.loads(en_file.read_text())["translations"]
 #[cfg(feature = "micropython")]
 use crate::micropython::qstr::Qstr;
 
-#[derive(Debug, Copy, Clone, FromPrimitive)]
+#[derive(Debug, Copy, Clone, FromPrimitive, PartialEq, Eq)]
 #[repr(u16)]
 #[allow(non_camel_case_types)]
 pub enum TranslatedString {

core/embed/rust/src/translations/translated_string.rs

@@ -32,7 +32,7 @@ impl TranslatedString {
     }
 
     pub const fn as_tstring(self) -> TString<'static> {
-        TString::Translation(self)
+        TString::from_translation(self)
     }
 }