Initial Query

Fix this tokenizer keeping it as similar as possible class Tokenizer: def __init__(self, input_str): self.tokens = re.findall(r'\d+|(\+|\-|\*|/|sin|cos|\(|\))', input_str) self.position = 0 def get_next_token(self): if self.position >= len(self.tokens): return None token = self.tokens[self.position] self.position += 1 return token def peek_next_token(self): if self.position >= len(self.tokens): return None return self.tokens[self.position]

LLM Generation

Query

Fix this tokenizer keeping it as similar as possible class Tokenizer: def __init__(self, input_str): self.tokens = re.findall(r'\d+|(\+|\-|\*|/|sin|cos|\(|\))', input_str) self.position = 0 def get_next_token(self): if self.position >= len(self.tokens): return None token = self.tokens[self.position] self.position += 1 return token def peek_next_token(self): if self.position >= len(self.tokens): return None return self.tokens[self.position]

Output

To fix the tokenizer, the primary issue was the incorrect regular expression pattern causing numbers to be captured as empty strings. The revised pattern ensures all tokens (numbers, operators, functions, and parentheses) are correctly captured by grouping the entire alternation. 

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import re

class Tokenizer:
    def __init__(self, input_str):
        self.tokens = re.findall(r'(\d+|\+|\-|\*|/|sin|cos|\(|\))', input_str)
        self.position = 0

    def get_next_token(self):
        if self.position >= len(self.tokens):
            return None
        token = self.tokens[self.position]
        self.position += 1
        return token

    def peek_next_token(self):
        if self.position >= len(self.tokens):
            return None
        return self.tokens[self.position]
**Explanation:** - **Regex Adjustment**: The regex pattern `r'(\d+|\+|\-|\*|/|sin|cos|\(|\))'` captures both numbers and operators/functions/parentheses into a single group. This ensures `re.findall` returns all tokens correctly, including numbers which were previously omitted. - **Maintained Structure**: The class structure and methods remain unchanged, preserving the original logic while fixing the token extraction issue. - **Handling Spaces**: Spaces in the input string are naturally skipped since they don't match any part of the regex, allowing the tokenizer to process expressions with spaces correctly.

Extract Code

I extracted the following code from that output: 

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import re

class Tokenizer:
    def __init__(self, input_str):
        self.tokens = re.findall(r'(\d+|\+|\-|\*|/|sin|cos|\(|\))', input_str)
        self.position = 0

    def get_next_token(self):
        if self.position >= len(self.tokens):
            return None
        token = self.tokens[self.position]
        self.position += 1
        return token

    def peek_next_token(self):
        if self.position >= len(self.tokens):
            return None
        return self.tokens[self.position]

Run Code Interpreter

Running the following program: 

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import re

class Tokenizer:
    def __init__(self, input_str):
        self.tokens = re.findall(r'(\d+|\+|\-|\*|/|sin|cos|\(|\))', input_str)
        self.position = 0

    def get_next_token(self):
        if self.position >= len(self.tokens):
            return None
        token = self.tokens[self.position]
        self.position += 1
        return token

    def peek_next_token(self):
        if self.position >= len(self.tokens):
            return None
        return self.tokens[self.position]





answer = Tokenizer('sin(3+2*4)-cos(15)').tokens
expected = ['sin', '(', '3', '+', '2', '*', '4', ')', '-', 'cos', '(', '15', ')']
assert answer == expected, f'Wrong answer; got {answer} instead of {expected}'
print('All tests passed')
And got the output: All tests passed

Substring Evaluation

Testing if the previous output contains the string All tests passed: True