Assignment 1 Solution

Write  a Lexer for the  source language  that you have chosen.  The  output of the  lexer must  be a “summary” of the tokens  in the program.

 
Example

For a program  in the C language:

Input:

main ( )

{

i n t  a  = 9 5 9 ;

f o o ( a ) ;

r e t u r n   0 ;

}


Expected Output:

Token
Occurrances
Lexemes
OP_ASGN
1
=
’(’
2
(
’)’
2
)
IDENTIFIER
3
a
 
 
foo
 
 
main
BLOCK_BEGIN
1
{
BLOCK_END
1
}
TYPE
1
int
KEYWORD_RET
1
return
INT_CONST
2
959
 
 
1
STMT_TERMINATOR
3
;
 

Details


• You are free to select your own token  names.

 

• Your implementation should read the source filename as its first command-line  parameter; it should produce its output on STDOUT.

 

• You must  use a lexer generator like Lex, Flex etc.

 

• The  tool  should  be robust;  any  failure  in tokenizing  due  to  errors  in the  input  program  must  be reported properly.

• You have to submit  a zipped folder (name  the folder “asgn1”) with:

–  the source of the implementation (in a folder called “src” within  “asgn1”;

–  a Makefile to  build  the  implementation (it  should  generate  an  executable  called  “lexer” in the  folder

“asgn1/bin”;

–  a set of at least 5 test  cases that you have used to check your implementation (in a folder “asgn1/test”);

–  a README  file with a brief description for building  and running  it (within  “asgn1”).

 

Binaries  should  NOT  be part  of the  submission.   Clean  the  folder of all object  and  executable  files before submission.


• We will apply  the  following set  of commands  to  build  and  run  your  implementation; make  sure  that your implementation works correctly  with these sequence of commands:

 

–  cd asgn1

–  make

–  bin/lexer test/test1.c (to execute  the first test-case  file test1.c)