Initial

advent/common/char_reader.py

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+from advent.common.provider import EofException
+from .char_provider import CharProvider
+
+
+class ReaderException(Exception):
+    pass
+
+
+class CharReader:
+    @staticmethod
+    def read_word(provider: CharProvider, word: str) -> str:
+        result = ''
+        for expected_char in word:
+            try:
+                char = provider.get()
+                if char == expected_char:
+                    result += char
+                else:
+                    raise ReaderException(f'Expected {word} but received {result}{char}')
+            except EofException:
+                raise ReaderException(f'Expected {word} but received {result}[EOF]')
+
+        return word
+
+    @staticmethod
+    def read_unsigned_int(provider: CharProvider) -> int:
+        if not provider.peek().isdigit():
+            raise ReaderException('Expected unsigned int')
+
+        number = 0
+        while not provider.finished() and provider.peek().isdigit():
+            number = number * 10 + int(provider.get())
+        return number