Move integer and char parsing out of the parser and back into the lexer

src/token.rs

@@ -4,11 +4,55 @@ use crate::span::Span;
 
 #[derive(Clone, Debug)]
 pub struct Token {
-    pub lexeme: String,
+    pub lexeme: Lexeme,
     pub kind: TKind,
     pub span: Span,
 }
 
+#[derive(Clone, Debug)]
+pub enum Lexeme {
+    String(String),
+    Integer(u128, u32),
+    Char(char),
+}
+
+impl Lexeme {
+    pub fn string(self) -> Option<String> {
+        match self {
+            Self::String(s) => Some(s),
+            _ => None,
+        }
+    }
+    pub fn str(&self) -> Option<&str> {
+        match self {
+            Self::String(s) => Some(s),
+            _ => None,
+        }
+    }
+    pub fn int(&self) -> Option<u128> {
+        match self {
+            Self::Integer(i, _) => Some(*i),
+            _ => None,
+        }
+    }
+    pub fn char(&self) -> Option<char> {
+        match self {
+            Self::Char(c) => Some(*c),
+            _ => None,
+        }
+    }
+}
+
+impl std::fmt::Display for Lexeme {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::String(v) => v.fmt(f),
+            Self::Integer(v, _) => v.fmt(f),
+            Self::Char(v) => v.fmt(f),
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum TKind {
     Comment,
@@ -19,6 +63,7 @@ pub enum TKind {
     Else,
     False,
     Fn,
+    For,
     If,
     Let,
     Loop,