Write a recursive descent parser for the expression grammar:
--> {+ | - }
--> { * | \ }
--> () |
--> a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z
The symbols { } | --> are metasymbols
Associate with each non-terminal an attribute which is the code to evaluate that non-terminals phrase using a stack machine. The stack machine instructions are PUSH, ADD, SUB, MUL, DIV, where a binary operator like ADD will pop the top two operands, compute the result and push it.
The expression (a + b) * (c - d) would have associated code:
PUSH a
PUSH b
ADD
PUSH c
PUSH d
SUB
MUL
(IF YOU CAN DO THIS BELOW PART WITHOUT ANY BIG PROBLEM GO AHEAD AND DO IT, IF NOT DON'T WORRY ABOUT IT AND LEAVE IT.)
Make the target machine a load/store architecture, where the above expression would translate to:
LOAD R1 a
LOAD R2, b
ADD R1, R1, R2
LOAD R2, c
LOAD R3, d
SUB R2, R2, R3
MUL R1, R1, R2
## Deliverables
1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done.
2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables):
a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment.
b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request.
3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement).
## Platform
Windows NT