ASSIGNMENT I Programming languages

ASSIGNMENT I

Write a program in each of the following three languages: (60 points – 20 per language)
i) Python
ii) Java
iii) SML
Consisting of a function that accepts two strings. Each string is the name of a file. The first is
the name of an input file and the second is the name of an output file. Name the function
‘hw1’.(Note that your program can also make use of other helper functions – just make sure
function ‘hw1’ takes as arguments the input file and output file that are specified in the program)
A pangram is a sentence that contains all the letters of the English alphabet at least once. For
example, the quick brown fox jumps over the lazy dog is a pangram. The program you are to
write must read in an input file( input.txt - a plain text file which contains 5 sentences), line by
line and check if the line read is a pangram or not. If the sentence read is a pangram, it writes
‘true’ to the output file. If it’s not, it writes ‘false’ to the output file.
For example, if input.txt contains:
we promptly judged antique ivory buckles for the next prize.
how quickly daft jumping zebras vex.
pottery is an art.
crazy fredrick bought many very exquisite opal jewels.
mr.dumbledore is a funny name for a dog.
Then your program must output to the output file:
true
true
false
true
false
NOTE : Output is case sensitive – please use all lower case in the output file. The example
provided here is formatted to human readability. Please look at the sample input output
files to see the precise formatting.
You can assume that input.txt contains exactly 5 sentences and all the letters are in lower case.
Please use the sample test cases provided to test your code. For the purpose of this assignment
you do not need to do any specific error checking on the files. Your program can assume that the
files exist (for the input file) or can be created or overwritten (for the output file).
Put your answers for Python, Java and SML in files named, respectively:
hw1.py
hw1.java
hw1.ml
PART I – PYTHON AND SML
Additional resources for python:
Skeleton code:
def hw1(input, output):
#read input file line by line
#for every line in input file, check if it contains all alphabets – store result
(true/false) in a variable
#write result to output file
# This last line is the function call to hw1 to test your code. Don’t include this in your
submission but use this line to test your code
hw1(‘input.txt’,’output.txt’)
Refer these for additional help:
Section 7.2 – Reading and Writing Files - https://docs.python.org/2/tutorial/inputoutput.html
For loops, Lists in Python - http://learnpythonthehardway.org/book/ex32.html
Additional resources for Python can be found on Piazza.
Modification 2/8/16
Typo! This should be hw1.sml
Additional resources for SML:
Skeleton code:
fun hw1(inFile : string, outFile : string) =
(* Open input and output file streams, read first input line from the input file stream *)
(* To read subsequent lines, you can make use of a helper function *) – see resources on SML
File Stream
(* Convert the string type of the lines read and alphabet string to list type*)
(* Perform alphabet checks on these lists *)
(*Write the resultant value – true or false to the output file *)
( * Remember to flush the outStream – refer resources on TestIO to see how flushOut is done. *)
(* This last line is the function call to hw1 to test your code. Don’t include this in your
submission but use this line to test your code *)
val _ = hw1(“input.txt”, “output.txt”)
SML File Stream resources :
You can use TextIO.openIn and TextIO.openOut for the file stream input and output.
To read each line from a file, you can use the TextIO.inputLine function. This function returns a
string option type. (Note that ‘string’ type and ‘string option’ type are different). The options it
returns are either NONE or SOME(c) depending on content of the line read. If a line is read
successfully, it returns SOME(c) and if there is no more data to read, it returns NONE. So to
keep reading the file line by line, your code has to keep reading as long as there is SOME(c). To
see how it works, refer to the last example in the following link:
http://www.cs.cornell.edu/courses/cs312/2006fa/recitations/rec09.html (See the last Example
using TextIO)
Resources on Strings and Chars :
http://sml-family.org/Basis/string.html#SIG:STRING.char:TY
http://sml-family.org/Basis/char.html#SIG:CHAR.char:TY:SPEC
Modification 2/8/16
PART II : JAVA
In the folder ‘java’, create an input.txt file containing any one of the sample input test cases.
Your code should be written in hw1.java
Create a ‘hw1’ class with a static method hw1() that takes in two strings as arguments – first for
the name of input file and second for the name of output file. Your function definition goes
inside the static method hw1().
You should have another class with a main method to test your code in a separate file. This file
shouldn’t be submitted – it is for your testing purposes only.
For instance:
Define hw1.java as :
public class hw1{
public static void hw1(inFile, outFile){
//function definition here
}
}
Define Tester.java as: (this is a separate file)
public class Tester{
public static void main(String[] args){
…
String input = “input.txt”;
String output = “output.txt”;
/* You can also read input and output as command line arguments – it doesn’t
matter as long as your input file is called input.txt and output file is output.txt */
hw1.hw1(input,output)
}
}
If you are using Eclipse or any other IDE’s make sure you do not create any packages since
this will not work when your code is moved to Timberlake (unless you have the appropriate
directories created) or on the testing script we use. To test your code on Timberlake, you can use
the following commands:
javac Tester.java (This should create a class file in the directory called Tester.class.)
java Tester (without the .class extension)
If executed correctly, your output file should now be populated with the test case results.
Modification 2/8/16
Modification
2/15/16
Instructions on how to submit the homework:
Create a folder UBITName_HW1 that contains three sub folders Python, SML and Java. The
‘Python’ folder should contain the following files :
hw1.py
Similarly ‘SML’ folder contains:
hw1.sml
And ‘Java’ folder contains:
hw1.java
For instance,
In Java folder,
Name of your root folder.
yourUBITname_HW1
Sub folders inside your
folder
Modification 2/8/16
In SML folder,
In Python folder,
NOTE:
- Make sure all your programs upon execution must read from the input.txt file and write to
output.txt file.
- You need NOT submit any input or output files
- Please do not include testing code in your submissions – this means your test program
that contains main() for Java will not be submitted, also NO function call to hw1() in
Python code or SML code. Our test script will have function calls to hw1().
Compress the UBITName_HW1 folder(UBITName_HW1.zip or UBITName_HW1.tar) and
submit it on Timberlake using the command submit_cse305 your_file_name
Please note, late submissions will not be accepted.
For information on how to run the various programming language compilers/interpreters:
https://wiki.cse.buffalo.edu/services/content/java
https://wiki.cse.buffalo.edu/services/content/standard-ml-new-jersey-smlnj
https://wiki.cse.buffalo.edu/services/content/python
You will find resources for these languages on the Piazza course web site, under the ‘Resources’
page.
You might also find the following page, listing available CSE systems, helpful too:
https://wiki.cse.buffalo.edu/services/content/student-systems