Menu
I am creating an infix expression parser, an so I have to create a tokenizer. It works well, except for one thing: I do not now how to differentiate negative number from the "-" operator.
For example, if I have:
23 / -23
The tokens should be 23, / and -23, but if I have an expression like
23-22
Then the tokens should be 23, - and 22.
I found a dirty workaround which is if I encounter a "-" followed by a number, I look at the previous character and if this character is a digit or a ')', I treat the "-" as an operator and not a number. Apart from being kind of ugly, it doesn't work for expressions like
--56
where it gets the following tokens: - and -56 where it should get --56
Any suggestion?
812
Negative numbers are represented in Two's Complement in assembly. In order to obtain Two's Complement of a number you have two options: to complement all it's bits and add one. to complement all it's bits until the last 1.
In natural language processing, tokenization is the process of breaking human-readable text into machine readable components. The most obvious way to tokenize a text is to split the text into words.
BERT uses what is called a WordPiece tokenizer. It works by splitting words either into the full forms (e.g., one word becomes one token) or into word pieces — where one word can be broken into multiple tokens. An example of where this can be useful is where we have multiple forms of words.
SubWord Tokenisation The core concept behind subwords is that frequently occurring words should be in the vocabulary, whereas rare words should be split into frequent sub words. Eg. The word “refactoring” can be split into “re”, “factor”, and “ing”.
In the first example the tokens should be 23, /, - and 23.
The solution then is to evaluate the tokens according to the rules of associativity and precedence. - cannot bind to / but it can to 23, for example.
If you encounter --56, is split into -,-,56 and the rules take care of the problem. There is no need for special cases.
68
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
