1 files changed, 60 insertions, 0 deletions
diff --git a/src/tokens/packed_binary_literal.rs b/src/tokens/packed_binary_literal.rs
new file mode 100644
index 0000000..1252398
--- /dev/null
+++ b/src/tokens/packed_binary_literal.rs
@@ -0,0 +1,60 @@
+use crate::*;
+
+
+pub struct PackedBinaryLiteral {
+    pub value: usize,
+    pub fields: Vec<BitField>,
+    pub errors: Vec<PackedBinaryLiteralParseError>,
+}
+
+impl PackedBinaryLiteral {
+    pub fn from_str(string: &str, parent: &Tokeniser) -> Self {
+        parse_packed_binary_literal(string, parent)
+    }
+}
+
+pub struct BitField {
+    pub name: char,
+    pub source: SourceSpan,
+    /// Length of field in bits
+    pub bits: usize,
+    /// Distance to left-shift field in value
+    pub shift: usize,
+}
+
+pub struct PackedBinaryLiteralParseError {
+    pub source: SourceSpan,
+    pub variant: PackedBinaryLiteralParseErrorVariant,
+}
+
+pub enum PackedBinaryLiteralParseErrorVariant {
+    DuplicateFieldName(char),
+    InvalidCharacter(char),
+}
+
+
+impl std::fmt::Display for PackedBinaryLiteral {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        if self.value == 0 {
+            write!(f, "0")?;
+        } else {
+            let bitcount = (self.value.ilog2() + 1) as usize;
+            'bit: for i in (0..bitcount).rev() {
+                if (i+1) % 4 == 0 {
+                    write!(f, "_")?;
+                }
+                for field in &self.fields {
+                    if i <= field.bits + field.shift - 1 && i >= field.shift {
+                        write!(f, "{}", field.name)?;
+                        continue 'bit;
+                    }
+                }
+                match (self.value >> i) & 1 {
+                    0 => write!(f, "0")?,
+                    _ => write!(f, "1")?,
+                }
+            }
+        }
+        return Ok(());
+    }
+}