pauliejes / BC4

We're getting loopy in this iteration, things might get a little iffy too

BC4

Build

This directory includes a make file that can be executed by running make from the command line, in addition you can run make clean to clear the directory of object files.

After running make, the compiled bc program will run interactively as well as using I/O redirection.

Start the program by running bc at the command line within the BC4 directory. In this iteration of BC the user is not allowed to enter an explicit expression without assigning that expression to a variable. Only the following grammar is accepted by this interpreter.

Grammar

<stmts>          → <stmt> <stmts>
                 | <stmt>
  
<stmt>           → id = <expr>
                 | if <cond> then <stmts> <optional_else> 
                 | while <cond> do <stmts> done
                 | print id
                 | #comment
                 | dump
                 | quit
  
<optional_else>  → else <stmts> fi 
                 | fi
  
<cond>           → <expr> <rel_op> <expr>
  
<rel_op>         → == | != | < | <= | > | >= 

<expr>           → <term> {(+ | -) <term>} 
  
<term>           → <factor> {(* |   / | %) <factor>} 
  
<factor>         → id 
                 | int_constant 
                 | ( <expr> )

Run

The user can input or redirect a file assigning variables, comparing variables with if - then - fi statements, and even execute while - do - done loops altering variables in new more efficient ways. The ability to add comments using the # character has also been added.

This is all nice, but to sweeten the deal we've also added a print function so that you can see the value of any given variable whenever you so please. If you want to see the whole program you've created, simply type dump and you'll get all the contents of the symbol table, along with the entire program inside bc thus far.

After trying all those new fun features, enter the quit command, and you'll find yourself back in the BC4 directory ready to check out our source code.

Sample input:

a = 0
while a <= 10 do 
a = a + 1
done
print a
#next I am goint to dump out the Symbol table AND the program up to this point (aka just the buffer)
dump
quit

Delegations:

Ryan - SymbolTable (except for dump, and new Hash), Started if statment & condition, multi-line if and while, buffer

Paulie - print, comment, buffer, finished out rest of if statement operators and started while. Hash function in symbol table.

Chris - buffer, comment, some if stmnt, dump function, symbol table debugging,

Shore - Inspiring our hearts and minds