Description
Your project is to use the grammar definition in the appendix
of your text to guide the construction of a lexical analyzer.
The lexical analyzer should return tokens as described. Keep
in mind these tokens will serve as the input to the parser.
Page 491 and 492 should be used to guide the construction of the
lexical analyzer. A few notable features:
0) the project’s general goal is to construct a list of tokens capable
of being passed to a parser.
1) comments should be totally ignored, not passed to the parser and
not reported.
2) one line comments are designated by //
3) multiple line comments are designated by /* followed by */ in
a match up fashion for the nesting.
Appropriate documentation as described in the Syllabus should
be included. A shar file, including all files necessary,
(makefile, source files, test files, documentation file
(“text” in ascii format), and any other files) should be submitted
by the deadline using turnin as follows:
turnin fn ree4620_1
By my typing make after unsharing your file, I should see an
executable called anything but p1,
The analyzer will be invoked with:
p1 test_fn
where p1 is the scirpt that will execute your scanner and
test_fn is the test filename upon which lexical analysis is to be
done. You must supply a makefile for any language you chose to use,
including scripting languages.
If you write in any language, you must supply at p1 file
that will execute your program.
For example, such a p1 file might appear as:
#!/bin/ksh
ruby your_ruby_script $1
OR
#!/bin/ksh
java your_java_pgm $1
OR
#!/bin/ksh
python your_python_script $1
OR
#!/bin/ksh
yourpgmname $1
Note that turnin will report the 2 day late date, if the project
is submitted on this date the penalty will be assessed.
The shar file can be created as follows:
shar fn1 fn2 fn3 fn4 > fn
You should NOT shar a directory, i.e. when I unshar your project
a new subdirectory should not be created.
You should test the integrity of your shar by:
1)copying your shar to a temporary directory,
2)unsharing,
3)make, and
4)execute to see that all files are present and that the
project works appropriately.
Failure to carefully follow these guidelines will result in penalty.
If you are not sure of some characteristic, ask to verify the
desired procedure.
You should echo the input line followed by the output in a
sequential fashion.
Note: you may have an additional project assigned before this one is
due.
SAMPLE INPUT:
/****This**********/
/**************/
/*************************
i = 333; ******************/ */
iiii = 3@33;
int g 4 cd (int u, int v) {
if(v == >= 0) return/*a comment*/ u;
else ret_urn gcd(vxxxxxxvvvvv, u-u/v*v);
/* u-u/v*v == u mod v*/
!
}
return void while void main()
!=
SAMPLE OUTPUT:
INPUT: /****This**********/
INPUT: /**************/
INPUT: /*************************
INPUT: i = 333; ******************/ */
*
/
INPUT: iiii = 3@33;
ID: iiii
=
INT: 3
Error: @33
;
INPUT: int g 4 cd (int u, int v) {
KW: INT
ID: g
INT: 4
ID: cd
(
KW: INT
ID: u
,
KW: INT
ID: v
)
{
INPUT: if(v == >= 0) return/*a comment*/ u;
KW: if
(
ID: v
==
>=
INT: 0
)
KW: return
ID: u
;
INPUT: else ret_urn gcd(vxxxxxxvvvvv, u-u/v*v);
KW: else
ID: ret
Error: _urn
ID: gcd
(
ID: vxxxxxxvvvvv
,
ID: u
–
ID: u
/
ID: v
*
ID: v
)
;
INPUT: /* u-u/v*v == u mod v*/
INPUT: !
Error: !
INPUT: }
}
INPUT: return void while void main()
KW: return
KW: void
KW: while
KW: void
ID: main
(
)
INPUT: !=
!=
