CSC 645 - Compiler Construction

Dr. R. M. Siegfried

Term Project Part 1 - Building a Scanner (Lexical Analyzer)

Due - Monday, February 20, 2023

Given the specifications for Pascal that is available on Moodle and on the class web page (https://home.siegfried/cs645/assignments.html), write a scanner that recognizes a function gettoken() that recognizes the lexemes of the language and returns a token corresponding to that lexeme.

Since we do not yet have a symbol table, all words (a letter followed by zero or more alphanumeric characters) have the temporary token tokword, all numbers have the temporary token toknumber and all others have the temporary token tokop.

If your input is the program

 
PROGRAM Sample (Input, Output);
  CONST
     x  = 15;
  BEGIN
    ...

  END;

Your initial output should be

 PROGRAM
 
     tokword 
 
 SAMPLE
 
          tokword 
 
 (         
 
                  tokop 
 
 INPUT       
 
        tokword 
 
 ,                    
 
        tokop 
 
 OUTPUT   
 
       tokword 
 
)          
 
                 tokop 
 
 ;             
 
              tokop 
 
 VAR      
 
             tokword 
 
 X                  
 
       tokword 
 
 =       
 
                   tokop 
 
 15   
 
                     toknumber 
 
 ;            
 
               tokop 
 
 

[Back to the Assignments Index]