diff --git a/libconlang/src/lib.rs b/libconlang/src/lib.rs
index 642a305..7702213 100644
--- a/libconlang/src/lib.rs
+++ b/libconlang/src/lib.rs
@@ -9,6 +9,7 @@ pub mod token {
     pub enum Type {
         Comment,
         Identifier,
+        Integer,
     }
     #[derive(Clone, Copy, Debug, PartialEq, Eq)]
     pub struct Token {
@@ -113,6 +114,16 @@ pub mod lexer {
                     .end()?,
             )
         }
+        pub fn integer(&mut self) -> Option<Token> {
+            self.skip_whitespace();
+            self.produce_token(
+                Type::Integer,
+                Rule::new(self.text())
+                    .and_maybe(|rule| rule.char('0').char_fn(|c| "xdob".contains(c)))
+                    .and_many(|this| this.char_fn(|c| c.is_ascii_hexdigit()))
+                    .end()?,
+            )
+        }
     }
 
     #[derive(Clone, Debug, PartialEq, Eq)]
@@ -305,6 +316,33 @@ mod tests {
                 assert_whole_input_is_token("123456789", Lexer::identifier, Type::Identifier);
             }
         }
+        mod integer {
+            use super::*;
+            #[test]
+            fn bare() {
+                assert_whole_input_is_token("10010110", Lexer::integer, Type::Integer);
+                assert_whole_input_is_token("12345670", Lexer::integer, Type::Integer);
+                assert_whole_input_is_token("1234567890", Lexer::integer, Type::Integer);
+                assert_whole_input_is_token("123456789ABCDEF0", Lexer::integer, Type::Integer);
+            }
+            #[test]
+            fn base16() {
+                assert_has_type_and_len("0x1234", Lexer::integer, Type::Integer, 6);
+                assert_has_type_and_len("0x1234 \"hello\"", Lexer::integer, Type::Integer, 6);
+            }
+            #[test]
+            fn base10() {
+                assert_whole_input_is_token("0d1234", Lexer::integer, Type::Integer);
+            }
+            #[test]
+            fn base8() {
+                assert_whole_input_is_token("0o1234", Lexer::integer, Type::Integer);
+            }
+            #[test]
+            fn base2() {
+                assert_whole_input_is_token("0b1010", Lexer::integer, Type::Integer);
+            }
+        }
     }
     mod parser {
         // TODO