more type casting to allow easy i32 extraction

src/structure/tfc/datatypes.rs

@@ -176,6 +176,12 @@ impl TdbDataType for u32 {
     }
 }
 
+impl FromLexical<u16> for u32 {
+    fn from_lexical<B: Buf>(b: B) -> Self {
+        b.reader().read_u16::<BigEndian>().unwrap() as u32
+    }
+}
+
 impl FromLexical<u32> for u32 {
     fn from_lexical<B: Buf>(b: B) -> Self {
         b.reader().read_u32::<BigEndian>().unwrap()
@@ -244,13 +250,49 @@ impl TdbDataType for i32 {
     }
 }
 
+impl FromLexical<i16> for i32 {
+    fn from_lexical<B: Buf>(b: B) -> Self {
+        b.reader().read_i16::<BigEndian>().unwrap() as i32
+    }
+}
+
+impl FromLexical<u16> for i32 {
+    fn from_lexical<B: Buf>(b: B) -> Self {
+        b.reader().read_u16::<BigEndian>().unwrap() as i32
+    }
+}
+
 impl FromLexical<i32> for i32 {
     fn from_lexical<B: Buf>(b: B) -> Self {
         let i = b.reader().read_u32::<BigEndian>().unwrap();
         (I32_BYTE_MASK ^ i) as i32
     }
 }
 
+impl ToLexical<u8> for i32 {
+    fn to_lexical(&self) -> Bytes {
+        <i32 as ToLexical<i32>>::to_lexical(&self as &i32)
+    }
+}
+
+impl ToLexical<u16> for i32 {
+    fn to_lexical(&self) -> Bytes {
+        <i32 as ToLexical<i32>>::to_lexical(&self as &i32)
+    }
+}
+
+impl ToLexical<i8> for i32 {
+    fn to_lexical(&self) -> Bytes {
+        <i32 as ToLexical<i32>>::to_lexical(&self as &i32)
+    }
+}
+
+impl ToLexical<i16> for i32 {
+    fn to_lexical(&self) -> Bytes {
+        <i32 as ToLexical<i32>>::to_lexical(&self as &i32)
+    }
+}
+
 impl ToLexical<i32> for i32 {
     fn to_lexical(&self) -> Bytes {
         let sign_flip = I32_BYTE_MASK ^ (*self as u32);

src/structure/tfc/typed.rs

@@ -39,6 +39,22 @@ impl TypedDictEntry {
         T::from_lexical(self.entry.as_buf())
     }
 
+    pub fn as_casted_val<T, Q: Into<T> + TdbDataType + FromLexical<Q>>(&self) -> T {
+        assert_eq!(Q::datatype(), self.datatype);
+        Q::from_lexical(self.entry.as_buf()).into()
+    }
+
+    pub fn as_i32(&self) -> Option<i32> {
+        match self.datatype {
+            Datatype::Int32 => Some(self.as_casted_val::<i32, i32>()),
+            Datatype::UInt8 => Some(self.as_casted_val::<i32, u8>()),
+            Datatype::Int8 => Some(self.as_casted_val::<i32, i8>()),
+            Datatype::UInt16 => Some(self.as_casted_val::<i32, u16>()),
+            Datatype::Int16 => Some(self.as_casted_val::<i32, i16>()),
+            _ => None,
+        }
+    }
+
     pub fn datatype(&self) -> Datatype {
         self.datatype
     }