from enum import Enum, auto
from collections import namedtuple

class AutoName(Enum):
    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name

class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()

# I always wanted to do this!!
all_tokens = list(Token)

TokenInfo = namedtuple('TokenInfo', ['tag', 'value'])

def token(tag):
    return TokenInfo(tag=tag, value=None)

def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""

    # TODO: move these helpers somewhere or hide inside a class?
    iterator = iter(s + " ")
    unchar_v = None

    def getchar():
        nonlocal unchar_v

        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char
            
    def unchar(char):
        nonlocal unchar_v
        unchar_v = char

    # start of the proper lexel
    
    simple_tokens = {
        "(": Token.LPAREN,
        ")": Token.RPAREN,
        "+": Token.PLUS,
        "*": Token.TIMES,
    }

    # note: we add the sentinel at the end to make sure
    # the number will be consumed in full
    while True:
        try:
            char = getchar()
            
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert(char is not None)
                unchar(char)
                yield TokenInfo(tag = Token.NUMBER, value = number)
                
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == " " or char == "\n":
                continue
            elif char == ":":
                char2 = getchar()
                if char2 != "=":
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ""
                while char.isalnum():
                    value += char
                    char = getchar()
                assert(char is not None)
                unchar(char)
                if value == "let":
                    yield token(Token.LET)
                elif value == "in":
                    yield token(Token.IN)
                elif value == "end":
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag = Token.ID, value = value)
            else:
                raise Exception(f"found unknown character while tokenizing: [{char}]")
        except StopIteration:
            break    
    yield token(Token.EOF)

def simplify(tokens):
    for (tag, value) in tokens:
        name = tag.name
        if value:
            yield name, value
        else:
            yield name

if __name__ == "__main__":
    example = "(1 + 11 * 22)"
    print(example)
    print(list(simplify(tokenize(example))))

    example2 = "let x := 1 in x + x end"
    print(example2)
    print(list(simplify(tokenize(example2))))

4b5fd75bd0b0cbc45cf0190fab3665ec1b2ebf39
<mask token>


class AutoName(Enum):

    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name


class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()


<mask token>


def token(tag):
    return TokenInfo(tag=tag, value=None)


def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""
    iterator = iter(s + ' ')
    unchar_v = None

    def getchar():
        nonlocal unchar_v
        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char

    def unchar(char):
        nonlocal unchar_v
        unchar_v = char
    simple_tokens = {'(': Token.LPAREN, ')': Token.RPAREN, '+': Token.PLUS,
        '*': Token.TIMES}
    while True:
        try:
            char = getchar()
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert char is not None
                unchar(char)
                yield TokenInfo(tag=Token.NUMBER, value=number)
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == ' ' or char == '\n':
                continue
            elif char == ':':
                char2 = getchar()
                if char2 != '=':
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ''
                while char.isalnum():
                    value += char
                    char = getchar()
                assert char is not None
                unchar(char)
                if value == 'let':
                    yield token(Token.LET)
                elif value == 'in':
                    yield token(Token.IN)
                elif value == 'end':
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag=Token.ID, value=value)
            else:
                raise Exception(
                    f'found unknown character while tokenizing: [{char}]')
        except StopIteration:
            break
    yield token(Token.EOF)


<mask token>

<mask token>


class AutoName(Enum):

    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name


class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()


<mask token>


def token(tag):
    return TokenInfo(tag=tag, value=None)


def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""
    iterator = iter(s + ' ')
    unchar_v = None

    def getchar():
        nonlocal unchar_v
        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char

    def unchar(char):
        nonlocal unchar_v
        unchar_v = char
    simple_tokens = {'(': Token.LPAREN, ')': Token.RPAREN, '+': Token.PLUS,
        '*': Token.TIMES}
    while True:
        try:
            char = getchar()
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert char is not None
                unchar(char)
                yield TokenInfo(tag=Token.NUMBER, value=number)
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == ' ' or char == '\n':
                continue
            elif char == ':':
                char2 = getchar()
                if char2 != '=':
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ''
                while char.isalnum():
                    value += char
                    char = getchar()
                assert char is not None
                unchar(char)
                if value == 'let':
                    yield token(Token.LET)
                elif value == 'in':
                    yield token(Token.IN)
                elif value == 'end':
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag=Token.ID, value=value)
            else:
                raise Exception(
                    f'found unknown character while tokenizing: [{char}]')
        except StopIteration:
            break
    yield token(Token.EOF)


def simplify(tokens):
    for tag, value in tokens:
        name = tag.name
        if value:
            yield name, value
        else:
            yield name


<mask token>

<mask token>


class AutoName(Enum):

    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name


class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()


<mask token>


def token(tag):
    return TokenInfo(tag=tag, value=None)


def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""
    iterator = iter(s + ' ')
    unchar_v = None

    def getchar():
        nonlocal unchar_v
        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char

    def unchar(char):
        nonlocal unchar_v
        unchar_v = char
    simple_tokens = {'(': Token.LPAREN, ')': Token.RPAREN, '+': Token.PLUS,
        '*': Token.TIMES}
    while True:
        try:
            char = getchar()
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert char is not None
                unchar(char)
                yield TokenInfo(tag=Token.NUMBER, value=number)
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == ' ' or char == '\n':
                continue
            elif char == ':':
                char2 = getchar()
                if char2 != '=':
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ''
                while char.isalnum():
                    value += char
                    char = getchar()
                assert char is not None
                unchar(char)
                if value == 'let':
                    yield token(Token.LET)
                elif value == 'in':
                    yield token(Token.IN)
                elif value == 'end':
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag=Token.ID, value=value)
            else:
                raise Exception(
                    f'found unknown character while tokenizing: [{char}]')
        except StopIteration:
            break
    yield token(Token.EOF)


def simplify(tokens):
    for tag, value in tokens:
        name = tag.name
        if value:
            yield name, value
        else:
            yield name


if __name__ == '__main__':
    example = '(1 + 11 * 22)'
    print(example)
    print(list(simplify(tokenize(example))))
    example2 = 'let x := 1 in x + x end'
    print(example2)
    print(list(simplify(tokenize(example2))))

from enum import Enum, auto
from collections import namedtuple


class AutoName(Enum):

    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name


class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()


all_tokens = list(Token)
TokenInfo = namedtuple('TokenInfo', ['tag', 'value'])


def token(tag):
    return TokenInfo(tag=tag, value=None)


def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""
    iterator = iter(s + ' ')
    unchar_v = None

    def getchar():
        nonlocal unchar_v
        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char

    def unchar(char):
        nonlocal unchar_v
        unchar_v = char
    simple_tokens = {'(': Token.LPAREN, ')': Token.RPAREN, '+': Token.PLUS,
        '*': Token.TIMES}
    while True:
        try:
            char = getchar()
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert char is not None
                unchar(char)
                yield TokenInfo(tag=Token.NUMBER, value=number)
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == ' ' or char == '\n':
                continue
            elif char == ':':
                char2 = getchar()
                if char2 != '=':
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ''
                while char.isalnum():
                    value += char
                    char = getchar()
                assert char is not None
                unchar(char)
                if value == 'let':
                    yield token(Token.LET)
                elif value == 'in':
                    yield token(Token.IN)
                elif value == 'end':
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag=Token.ID, value=value)
            else:
                raise Exception(
                    f'found unknown character while tokenizing: [{char}]')
        except StopIteration:
            break
    yield token(Token.EOF)


def simplify(tokens):
    for tag, value in tokens:
        name = tag.name
        if value:
            yield name, value
        else:
            yield name


if __name__ == '__main__':
    example = '(1 + 11 * 22)'
    print(example)
    print(list(simplify(tokenize(example))))
    example2 = 'let x := 1 in x + x end'
    print(example2)
    print(list(simplify(tokenize(example2))))

from enum import Enum, auto
from collections import namedtuple

class AutoName(Enum):
    @staticmethod
    def _generate_next_value_(name, start, count, last_values):
        return name

class Token(AutoName):
    LPAREN = auto()
    RPAREN = auto()
    PLUS = auto()
    TIMES = auto()
    NUMBER = auto()
    LET = auto()
    ID = auto()
    ASSIGN = auto()
    IN = auto()
    END = auto()
    EOF = auto()

# I always wanted to do this!!
all_tokens = list(Token)

TokenInfo = namedtuple('TokenInfo', ['tag', 'value'])

def token(tag):
    return TokenInfo(tag=tag, value=None)

def tokenize(s):
    """Tokenize the given string s into a generator of tokens."""

    # TODO: move these helpers somewhere or hide inside a class?
    iterator = iter(s + " ")
    unchar_v = None

    def getchar():
        nonlocal unchar_v

        if unchar_v is not None:
            char = unchar_v
            unchar_v = None
        else:
            char = next(iterator)
        return char
            
    def unchar(char):
        nonlocal unchar_v
        unchar_v = char

    # start of the proper lexel
    
    simple_tokens = {
        "(": Token.LPAREN,
        ")": Token.RPAREN,
        "+": Token.PLUS,
        "*": Token.TIMES,
    }

    # note: we add the sentinel at the end to make sure
    # the number will be consumed in full
    while True:
        try:
            char = getchar()
            
            if char.isdigit():
                number = 0
                while char.isdigit():
                    number *= 10
                    number += int(char)
                    char = getchar()
                assert(char is not None)
                unchar(char)
                yield TokenInfo(tag = Token.NUMBER, value = number)
                
            elif char in simple_tokens:
                yield token(simple_tokens[char])
            elif char == " " or char == "\n":
                continue
            elif char == ":":
                char2 = getchar()
                if char2 != "=":
                    raise Exception("Expected '=' after ':' [let _ := _ in _]")
                yield token(Token.ASSIGN)
            elif char.isalnum():
                value = ""
                while char.isalnum():
                    value += char
                    char = getchar()
                assert(char is not None)
                unchar(char)
                if value == "let":
                    yield token(Token.LET)
                elif value == "in":
                    yield token(Token.IN)
                elif value == "end":
                    yield token(Token.END)
                else:
                    yield TokenInfo(tag = Token.ID, value = value)
            else:
                raise Exception(f"found unknown character while tokenizing: [{char}]")
        except StopIteration:
            break    
    yield token(Token.EOF)

def simplify(tokens):
    for (tag, value) in tokens:
        name = tag.name
        if value:
            yield name, value
        else:
            yield name

if __name__ == "__main__":
    example = "(1 + 11 * 22)"
    print(example)
    print(list(simplify(tokenize(example))))

    example2 = "let x := 1 in x + x end"
    print(example2)
    print(list(simplify(tokenize(example2))))
