Build a hash table using chaining as the collision resoultion technique. Insertions into the hash table will correspond to declarations of variables and values in a program, searches will be requests for the value of a variable. Some variables will be local and have a narrow scope while some variables will be global.
The program will take input from a file, another program written in the omnipotent programming language BORG (Bionicly Omnipotent Resistance Grinders) and generate ouput from this program.
The BORG language has the following commands (keywords):
- START-FINISH blocks. Indicating different scopes.
- COM - Single line comments: Text should be ignored if on the same line
- value = expression – Assignment statements, ie GEORGE = 122. This language is not option explicit, so the statement GEORGE = 122 will put a variable into the table and associate the value 122 with it.
- ++ - increment operator, syntax: VARIABLE ++
- -- - decrement operator, syntax: VARIABLE --
- expressions, expressions are limited to unary and binary arithmatic, or variable names
- supported operators: + - / * % ^ (plus, minus, divide, multiple, modulo, exponent)
- PRINT – syntax PRINT expression. If the expression is a variable, and this variable is not in scope, then an error message indicating unknow variable x at line number y. The value printed if there is a variable in scope should be the variable with the closest scope.
- errors – other than the print statements, our interpreter will not be responsible for detecting errors, syntax errors should be disregarded if encountered, assume that the source file is correct.
Our hash function: sum the ordinal values of the characters of the variable multiplied by their position in the string (1-indexing), then taking the modulo by TABLESIZE.
ie. The variable ABC = (65 * 1 + 66 * 2 + 67 * 3) % TABLESIZE
All tokens are seperated by one space or a new line.
Output: for this , run your interpreter on this sample source program as well as a program of your own, and turn it the output from both, as well as the source code from your BORG program as well as source code of the assignment and its executable. Zip is good.
may implement one additional feature to the language, such as adding if, methods, more capable print statements. Only one student may implement a given extension to the language, and each extension must first be cleared with me.
Sample program and its output:
Input
COM HERE IS OUR FIRST BORG PROGRAM
COM WHAT A ROBUST LANGUAGE IT IS
START
BORAMIR = 25
LEGOLAS = 101
PRINT BORAMIR
BORAMIR ++
PRINT LEGOLAS LEGOLAS IS 25
PRINT BORAMIR * 2
COM
COM NESTED BLOCK
COM
START
GANDALF = 49
PRINT GANDALF
PRINT BORAMIR
FINISH
PRINT GANDALF
START
LEGOLAS = 1000
PRINT LEGOLAS
FINISH
PRINT LEGOLAS
LEGOLAS --
PRINT LEGOLAS
FINISH
OUTPUT
Output
BORAMIR IS 25
LEGOLAS IS 25
GANDALF IS UNDEFINED
BOARAMIR * 2 IS 50
GANDALF IS 49
BORAMIR IS 25
GANDALF IS UNDEFINED
LEGOLAS IS 1000
LEGOLAS IS 101
LEGOLAS IS 101
CAn anybody write code for this program?
Thank uu