1 files changed, 15 insertions(+), 12 deletions(-)

M src/bitstream.rs

@@ 10,14 10,17 @@ pub struct Header {
     pub bitstream_length: u32
 }
 
-pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
-    // See http://www.fpga-faq.com/FAQ_Pages/0026_Tell_me_about_bit_files.htm.
-    const DESIGN_NAME_TAG: u8 = 0x61;
-    const PART_NAME_TAG: u8 = 0x62;
-    const DESIGN_DATE_TAG: u8 = 0x63;
-    const DESIGN_TIME_TAG: u8 = 0x64;
-    const BITSTREAM_TAG: u8 = 0x65;
+// See http://www.fpga-faq.com/FAQ_Pages/0026_Tell_me_about_bit_files.htm.
+#[repr(u8)]
+enum Tag {
+    DesignName = 0x61,
+    PartName = 0x62,
+    DesignDate = 0x63,
+    DesignTime = 0x64,
+    Bitstream = 0x65
+}
 
+pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // Skip the first two fields.
     let length = read_u16(reader).or_else(|_| invalid_data("read length failed"))? as usize;
 


@@ 34,7 37,7 @@ pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // The design name.
     let tag = read_u8(reader).or_else(|_| invalid_data("error reading design name tag"))?;
 
-    if tag != DESIGN_NAME_TAG {
+    if tag != Tag::DesignName as u8 {
         return invalid_data("expected design name tag");
     }
 


@@ 43,7 46,7 @@ pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // The part name.
     let tag = read_u8(reader).or_else(|_| invalid_data("error reading part name tag"))?;
 
-    if tag != PART_NAME_TAG {
+    if tag != Tag::PartName as u8 {
         return invalid_data("expected part name tag");
     }
 


@@ 52,7 55,7 @@ pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // The design date.
     let tag = read_u8(reader).or_else(|_| invalid_data("error reading design date tag"))?;
 
-    if tag != DESIGN_DATE_TAG {
+    if tag != Tag::DesignDate as u8 {
         return invalid_data("expected design date tag");
     }
 


@@ 61,7 64,7 @@ pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // The design time.
     let tag = read_u8(reader).or_else(|_| invalid_data("error reading design time tag"))?;
 
-    if tag != DESIGN_TIME_TAG {
+    if tag != Tag::DesignTime as u8 {
         return invalid_data("expected design time tag");
     }
 


@@ 70,7 73,7 @@ pub fn read_header<R: Read>(reader: &mut R) -> io::Result<Header> {
     // The bitstream length.
     let tag = read_u8(reader).or_else(|_| invalid_data("error reading bitstream tag"))?;
 
-    if tag != BITSTREAM_TAG {
+    if tag != Tag::Bitstream as u8 {
         return invalid_data("expected bitstream tag");
     }