Programming Assignment 01 Solution

Purpose:




* Demonstrate working programming environment(s).

* Demonstrate elementary understanding of Regular Expressions and

how to use them in a program.




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Background:




* The input file will have multiple proposed tokens on each line.

* The proposed tokens will be separated by whitespace, which is to

be ignored.




* Your program will consider successive tokens from the input file

and classify them as 'ID', 'FP', 'INT', or 'does not match'.




* An ID starts with a letter or underscore, followed by any number

of letters, digits, or underscores.

* An INT is any number (greater than 0) of decimal digits.

* An FP is any number (greater than 0) of decimal digits, followed

by a decimal point, followed by any number (greater than 0) of

decimal digits. (This definition of FP is simpler than what we

discussed in class. This definition requires digit both before

and after the decimal point.)




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Examples:




_a00q is a legal ID.

0_a_f is not a legal ID (it starts with a digit).

0_a_f is not a legal INT (it has letters and underscores).

0_a_f is not a legal FP (it has letters and underscores, it does

not have a decimal point).

0_a_f should be identified as 'does not match'.

456 is a legal INT.

123. is not a legal FP (it has no digits after the decimal point).

.123 is not a legal FP (it has on digits before the decimal point).

456.654 is a legal FP.




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Tasks:




1. Download HMWK_01.zip from Blackboard.

2. Unzip the file somewhere convenient.

3. Change 'dalioba' in the name of the directory to your NetID.

(Your NetID is three letters followed by four or five digits.

The directory name will now be something like 'hmwk_01_abc1234'.)

4. Look in that directory.

5. Pick a language in which to write your code, C , Java, or Python.

6. Change the header lines in the skeleton file hmwk_01.cs / .java / .py.

(Put your name on line 1, your ID number on line 2, and the date on

line 3.)

7. Run the skeleton file you just changed with the provided

'inputdata.text' as the input file.

8. Observe the following output (it will be the same no matter which

language you picked):




processing tokens from inputdata.txt ...

12345< is the proposed token.

67890< is the proposed token.

afghe< is the proposed token.

abcde< is the proposed token.

23456< is the proposed token.

0abcd< is the proposed token.

34567< is the proposed token.

__fred01< is the proposed token.

45678< is the proposed token.

123.456< is the proposed token.

12345a< is the proposed token.

123.< is the proposed token.

.456< is the proposed token.

ab00cd< is the proposed token.

00ab00< is the proposed token.




9. Now, change the contents of processToken() function to use the

regular expression support of the language you selected so that

the following output is generated for the 'inputdata.txt' test

cases.




processing tokens from inputdata.txt ...

12345< matches INT

67890< matches INT

afghe< matches ID

abcde< matches ID

23456< matches INT

0abcd< does not match.

34567< matches INT

__fred01< matches ID

45678< matches INT

123.456< matches FP

12345a< does not match.

123.< does not match.

.456< does not match.

ab00cd< matches ID

00ab00< does not match.




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Submission:




Make a zipfile of your 'hmwk_01_xxxnnnnn' directory and submit it on

Blackboard as your results for this assignment. Even if you are only

submitting a single document, you still need to put it in a directory

and zip that directory.




Your submission will be run on another file of test data. That file

will have 10 possible tokens and your solution will score a point for

each token that generates the correct message.




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Bonus Points:




After you are confident that you have correctly updated the code in

one of the skeleton files, do another language. So if you did Java

first, try doing C or Python. You'll get 1/2 point for each of the

10 possible tokens your second language attempt properly converts.




If you finish a second language, do the third language. You'll get

an additional 1/2 point for each of the 10 possible tokens your third

language attempt properly converts.




Therefore, the maximum possible score for this homework assignment

is 20 points (10 + 5 + 5) out of 10.




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Hints:

1. You might need some lines of static code lines aside from

changing the contents of processToken(). (This will depend on

how you decide to do the regular expressions.)




2. This program is not complex. The processToken() routine in the

C proposed solution is 15 lines of code, including some static

data. For Java, it's 12 lines of code. For Python, it's 16

lines of code, including some static data. If you find yourself

writing lots more code than this, you're probably going down the

wrong path.




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