CODEWITHSUNDEEP
javalexical
user1023875
user1023875

Reputation: 31

Creating a simple lexical analyser in Java

I am creating a lexical analyser that must read a text input and output tokens for a basic 'created' language and should output a token when called. I would like it to distinguish between identifiers, constants etc.. from a list of which I pre-determine.

I need to read the text file using an input stream. A while loop will loop through chars individually but I need it to recognise if the chars scanned are an identifier or a '+' '-' '*' '/' etc... what would be the best way to do this?

I am fairly new to programming so any advice on how to construct this would be appreciated. many thanks for any answers

Upvotes: 3

Views: 3569

Answers (2)

H-Man2
H-Man2

Reputation: 3189

Do not try to write your own lexer / parser.

It is easier to use a lexer/parser generator like ANTLR or SableCC.

Upvotes: 4

user142162
user142162

Reputation:

The StreamTokenizer class will probably help you out the most. It will read and distinguish between identifiers, numbers, and strings. You can also configure it to identify operators, such as +, *, etc.

Upvotes: 2

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