Initial commit: Basic interpreter structure

src/lexer.py

@@ -0,0 +1,51 @@
+import re
+
+class Token:
+    def __init__(self, type, value):
+        self.type = type
+        self.value = value
+
+    def __repr__(self):
+        return f'Token({self.type}, {self.value!r})'
+
+class Lexer:
+    def __init__(self, text):
+        self.text = text
+        self.pos = 0
+
+    def error(self):
+        raise Exception('Invalid character')
+
+    def get_next_token(self):
+        if self.pos > len(self.text) - 1:
+            return Token('EOF', None)
+
+        current_char = self.text[self.pos]
+
+        if current_char.isspace():
+            self.pos += 1
+            return self.get_next_token()
+
+        if current_char == '"':
+            self.pos += 1
+            string_end = self.text.find('"', self.pos)
+            if string_end == -1:
+                self.error()
+            string = self.text[self.pos:string_end]
+            self.pos = string_end + 1
+            return Token('STRING', string)
+
+        if re.match(r'\bUwU Boy\b', self.text[self.pos:]):
+            self.pos += 7
+            return Token('PRINT', 'UwU Boy')
+
+        self.error()
+
+    def tokenize(self):
+        tokens = []
+        while True:
+            token = self.get_next_token()
+            tokens.append(token)
+            if token.type == 'EOF':
+                break
+        return tokens