SRL Archive - General

Alright so I originally had to do this for my Computer Science class as part of a competition. The challenge is to write a command prompt calculator. You can use any programming language you want. It has to recieve input from the user and print the result (REPL). It has to support all the basic math operators (+, -, *, /, %). Optionally you can add functionality for symbol definition, similar to how Bjarne Stroustrup did with his calculator in his "C++ Programming Language" book:

table["pi"] = 3.1415926535897932385;

Have fun, there's more than one way to do this. I hope to see some of your solutions soon, and I will post mine 24 hours from now.

Gah, I had one a longgg time ago.

Had all the basics, fractions, basic algebra.
Going to go look for it. (Was made with C++)

I guess I'll wait another day since nobody has posted code yet :/

I'm pretty new to C++ but here is mine:

#include <iostream>
#include <windows.h>
using namespace std;

void Add()
{
     double a, b, c;
     cout << "Enter the first number" << endl;
     cin >> a;
     cout << "Enter the second number" << endl;
     cin >> b;
     c = a + b;
     cout << a;
     cout << " + ";
     cout << b;
     cout << " is equal to: ";
     cout << c << endl;
}  

void Subtract()
{
     double a, b, c;
     cout << "Enter the first number" << endl;
     cin >> a;
     cout << "Enter the second number" << endl;
     cin >> b;
     c = a - b;
     cout << a;
     cout << " - ";
     cout << b;
     cout << " is equal to: ";
     cout << c << endl;
} 

void Multiply()
{
     double a, b, c;
     cout << "Enter the first number" << endl;
     cin >> a;
     cout << "Enter the second number" << endl;
     cin >> b;
     c = a * b;
     cout << a;
     cout << " * ";
     cout << b;
     cout << " is equal to: ";
     cout << c << endl;
}

void Divide()
{
     double a, b, c;
     cout << "Enter the first number" << endl;
     cin >> a;
     cout << "Enter the second number" << endl;
     cin >> b;
     c = a / b;
     cout << a;
     cout << " / ";
     cout << b;
     cout << " is equal to: ";
     cout << c << endl;
}  

int main()
{
    int input;

    cout << "What operation to perform (Add(1), Subtract(2), Multiply(3), Divide(4))" << endl;
    cin >> input;
    switch ( input ) {
    case 1:
         Add();
         break;
    case 2:
         Subtract();
         break;
    case 3:
         Multiply();
         break;
    case 4:
         Divide();
         break;
    default:         
         cout<<"Error, bad input, quitting\n";
         break;
    
    }
    system("PAUSE");
   
}

http://villavu.com/forum/showthread.php?t=52254 :)
Can be easily extended for constants (parsing is already there).

#include <iostream>
#include <string>

static const int MAX_SIZE = 1000;

static const int operatorCount = 7;
static const char operators[operatorCount] = {
	'=','+','-','*','/','%','^'
};
static const int constantCount = 4;
static const int constantLength = 7;
static double constantValue[constantCount] = {
	3.14159265359, // pi
	2.71828182846, // e
	1337.0
	0 
};
static const char constants[constantCount][constantLength] = {
	"pi",
	"e",
	"emaziz",
	"zyt3x",
};

static const int variableCount = 26;
static char variables[26][MAX_SIZE];

struct expression {
private:
	char expr[MAX_SIZE];
	int findOperator(char& op) {
		int paradepth = 0;
		for(int j = 0; j < operatorCount; j++)
			for(int i = 0; i < MAX_SIZE && expr[i] != 0; i++) {
				if(expr[i] == '(') paradepth++; else if(expr[i] == ')') paradepth--;
				else if(expr[i] == operators[j] && paradepth == 0) {
					op = expr[i];
					return i;
				};
			};
		return -1;
	};
public:
	expression() { for(int i = 0; i < MAX_SIZE; i++) expr[i] = 0; };
	expression(const char* cs) {
		int rsize = 0;
		for(int i = 0; i < MAX_SIZE && cs[i] != '\n'; i++)
			if(cs[i] != ' ') expr[rsize++] = cs[i];
	};

	double parse() {
		char op;
		int oploc = findOperator(op);
		if(oploc > -1) {
			char lexpr[MAX_SIZE] = {0};
			char rexpr[MAX_SIZE] = {0};
			for(int i = 0; i < oploc; i++)
				lexpr[i] = expr[i];
			for(int i = 0; i < MAX_SIZE; i++)
				rexpr[i] = expr[oploc+i+1];
			double lexprres = expression(lexpr).parse();
			double rexprres = expression(rexpr).parse();
			switch(op) {
			case '+':
				return lexprres + rexprres;
			case '-':
				return lexprres - rexprres;
			case '*':
				return lexprres * rexprres;
			case '/':
				return lexprres / rexprres;
			case '%':
				return (int)lexprres % (int)rexprres;
			case '^':
				return pow(lexprres,rexprres);
			case '=':
				if(isalpha(lexpr[0]) && !isalpha(lexpr[1])) {
					int var = tolower(lexpr[0])-97;
					for(int i = 0; i < MAX_SIZE; i++)
						variables[var][i] = rexpr[i];
					std::cout << "Set variable '" << lexpr[0] << "' to " << rexpr << "." << std::endl;
					return 0;
				};
			default:
				std::cout << "WHAT KIND OF FUCKING OPERATOR IS THIS?!" << std::endl;
				return 0;
			};
		} else {
			// Check if it is paranthesis-expression, remove paranthesis
			if(expr[0] == '(') {
				char cs[MAX_SIZE] = { 0 };
				int paradepth = 0;
				for(int i = 1; i < MAX_SIZE && (expr[i] != ')' || paradepth != 0); i++) {
					if(expr[i] == '(') paradepth++; else if(expr[i] == ')') paradepth--;
					cs[i-1] = expr[i];
				};
				return expression(cs).parse();
			};
			// Check if function or constant
			if(isalpha(expr[0])) {
				// Check for constant
				for(int i = 0; i < constantCount; i++)
					for(int j = 0; j < constantLength; j++) 
						if(expr[j] != constants[i][j])
							break;
						else if(j == constantLength-1)
							return constantValue[i];
				// Check for variable
				if(!isalpha(expr[1])) {
					return expression(variables[tolower(expr[0])-97]).parse();
				};
			};
			return _atof_l(expr,0);;
		};
	};
};

int main() {
	char input[MAX_SIZE] = {0};
	while(true) {
		std::cout << "Enter a mathematical expression to calculate, or nothing to quit: " << std::endl;
		for(int i = 0; i < MAX_SIZE; i++)
			input[i] = 0;
		std::cin.getline(input,1000);
		if(input[0] == 0)
			break;
		double result = 0;
		std::cout << expression(input).parse() << std::endl << std::endl;
	};
	std::cout << "See ya later, alligator!" << std::endl;
	_sleep(1000);
};

Hey, this was fun! :D Only supports the basic operators but I think I'll add constants and trigonometric functions later. ^^,

EDIT: Forgot ^-operator
EDIT2: Crap, I just spilled soda all over my shirt!
EDIT3: Carrot soup is actually pretty tasty. Who would've known?! Now I has added paranthesis support!
EDIT4: WHUDDUP, now it even supports constants 'e' and 'pi' as well as variables which is any single letter and can be set with like "x = 5", or even freaking "y = x^2" and then you can change x and y will be changed as well! WHAT SORCERY IS THIS??? I shall go to work now.

Very basic calc with 4 math operator support (+,-,*,/). Just for fun:
Language assembler.

;This program was created on assembler editor
.486
.model flat,stdcall
option casemap:none
WinMain proto :DWORD,:DWORD,:DWORD,:DWORD
include include\windows.inc
include include\user32.inc
include include\kernel32.inc


includelib lib\user32.lib
includelib lib\kernel32.lib

.data

ClassName db "SimpleWinClass",0
AppName  db "JustCalc",0
MenuName db "FirstMenu",0

ButtonClassName db "button",0
EditClassName db "edit",0
LabelClassName DB "STATIC", 0


ButtonText2 db "+",0
ButtonText3 db "-",0
ButtonText4 db "*",0
ButtonText5 db "/",0

text1 db "Number1",0
text2 db "Number2",0

dlg db "ok",0


format db '%d',0

.data?
op1 dd 0
op2 dd 0
result dd 0

string db 30 DUP(0)
hInstance HINSTANCE ?
CommandLine LPSTR ?

hwndButton HWND ?
hwndButton2 HWND ?
hwndButton3 HWND ?
hwndButton4 HWND ?


hwndEdit HWND ?
hwndEdit2 HWND ?


hwndLabell DD ?
hwndLabell2 DD ?






.const
ButtonID equ 1
Button2ID equ 2
Button3ID equ 3
Button4ID equ 12

EditID equ 4
Edit2ID equ 5

LabelID EQU 8
Label2ID equ 9




.code
start:

	invoke GetModuleHandle, NULL
	mov    hInstance,eax
	invoke GetCommandLine
	mov CommandLine,eax
	invoke WinMain, hInstance,NULL,CommandLine, SW_SHOWDEFAULT
	 invoke ExitProcess,eax

	
	WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
	.IF uMsg==WM_DESTROY
		invoke PostQuitMessage,NULL
	.ELSEIF uMsg==WM_CREATE
	
	         invoke CreateWindowEx, NULL,ADDR LabelClassName, NULL,WS_CHILD or WS_VISIBLE ,12, 1, 130, 15, hWnd, LabelID,hInstance, NULL
                 mov hwndLabell, eax
	         invoke SetWindowText, hwndLabell, ADDR text1

	          invoke CreateWindowEx, NULL,ADDR LabelClassName, NULL,WS_CHILD or WS_VISIBLE ,12, 41, 130, 15, hWnd, Label2ID,hInstance, NULL
                 mov hwndLabell2, eax
	         invoke SetWindowText, hwndLabell2, ADDR text2
	         
		invoke CreateWindowEx,WS_EX_CLIENTEDGE, ADDR EditClassName,NULL,WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT or ES_AUTOHSCROLL or ES_NUMBER,12,18,160,25,hWnd,EditID,hInstance,NULL
		mov  hwndEdit,eax
		invoke SetFocus, hwndEdit

                invoke CreateWindowEx,WS_EX_CLIENTEDGE, ADDR EditClassName,NULL,WS_CHILD or WS_VISIBLE or WS_BORDER or ES_LEFT or ES_AUTOHSCROLL or ES_NUMBER,12,60,160,25,hWnd,Edit2ID,hInstance,NULL
		mov  hwndEdit2,eax

		
		invoke CreateWindowEx,NULL, ADDR ButtonClassName,ADDR ButtonText2,WS_CHILD or WS_VISIBLE or BS_DEFPUSHBUTTON,15,100,22,25,hWnd,ButtonID,hInstance,NULL
		mov  hwndButton,eax
		
		invoke CreateWindowEx,NULL, ADDR ButtonClassName,ADDR ButtonText3,WS_CHILD or WS_VISIBLE or BS_DEFPUSHBUTTON,60,100,22,25,hWnd,Button2ID,hInstance,NULL
		mov  hwndButton2,eax

                invoke CreateWindowEx,NULL, ADDR ButtonClassName,ADDR ButtonText4,WS_CHILD or WS_VISIBLE or BS_DEFPUSHBUTTON,105,100,22,25,hWnd,Button3ID,hInstance,NULL
		mov  hwndButton3,eax

                invoke CreateWindowEx,NULL, ADDR ButtonClassName,ADDR ButtonText5,WS_CHILD or WS_VISIBLE or BS_DEFPUSHBUTTON,150,100,22,25,hWnd,Button4ID,hInstance,NULL
		mov  hwndButton4,eax
		



        .ELSEIF uMsg==WM_COMMAND
		mov eax,wParam
		.IF lParam==0

		.ELSE
		

		            .IF ax==ButtonID
				shr eax,16
				.IF ax==BN_CLICKED
                                invoke  GetDlgItemInt,hWnd,EditID,0,1
                                 mov op1,eax

                                    invoke  GetDlgItemInt,hWnd,Edit2ID,0,1
                                  add eax,op1
                                    invoke wsprintf,addr string,addr format,eax
                                      invoke MessageBox,0,addr string,addr dlg,MB_OK
                                	.ENDIF
					.ENDIF

		
		
			.IF ax==Button2ID
				shr eax,16
				.IF ax==BN_CLICKED
                                 invoke  GetDlgItemInt,hWnd,EditID,0,1
                                 mov op1,eax

                                    invoke  GetDlgItemInt,hWnd,Edit2ID,0,1
                                  sub eax,op1
                                  neg eax
                                    invoke wsprintf,addr string,addr format,eax
                                      invoke MessageBox,0,addr string,addr dlg,MB_OK

                                        .ENDIF
					.ENDIF
					
                                            .IF ax==Button4ID
				shr eax,16
				.IF ax==BN_CLICKED
                                 invoke  GetDlgItemInt,hWnd,Edit2ID,0,1
                                  mov     ebx,eax
                                 invoke  GetDlgItemInt,hWnd,EditID,0,1
                                  div     ebx
                                  
                                    invoke wsprintf,addr string,addr format,eax
                                      invoke MessageBox,0,addr string,addr dlg,MB_OK
                                           .ENDIF
					.ENDIF
					 
                                        .IF ax==Button3ID
				shr eax,16
				.IF ax==BN_CLICKED
                                    invoke  GetDlgItemInt,hWnd,EditID,0,1
                                 mov op1,eax

                                    invoke  GetDlgItemInt,hWnd,Edit2ID,0,1
                                  imul eax,op1
                                    invoke wsprintf,addr string,addr format,eax
                                      invoke MessageBox,0,addr string,addr dlg,MB_OK





					.ENDIF
                                        .ENDIF
                                         .ENDIF
					


 .ELSE
		invoke DefWindowProc,hWnd,uMsg,wParam,lParam
		ret
 .ENDIF
	xor    eax,eax
	ret
WndProc endp

	
WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:DWORD
	LOCAL wc:WNDCLASSEX
	LOCAL msg:MSG
	LOCAL hwnd:HWND
	mov   wc.cbSize,SIZEOF WNDCLASSEX
	mov   wc.style, CS_HREDRAW or CS_VREDRAW
	mov   wc.lpfnWndProc, OFFSET WndProc
	mov   wc.cbClsExtra,NULL
	mov   wc.cbWndExtra,NULL
	push  hInst
	pop   wc.hInstance
	mov   wc.hbrBackground,COLOR_BTNFACE+1
	mov   wc.lpszMenuName,OFFSET MenuName
	mov   wc.lpszClassName,OFFSET ClassName
	invoke LoadIcon,NULL,IDI_APPLICATION
	mov   wc.hIcon,eax
	mov   wc.hIconSm,eax
	invoke LoadCursor,NULL,IDC_ARROW
	mov   wc.hCursor,eax
	invoke RegisterClassEx, addr wc
	INVOKE CreateWindowEx,WS_EX_CLIENTEDGE,ADDR ClassName,ADDR AppName,\
           WS_SYSMENU,CW_USEDEFAULT,\
           CW_USEDEFAULT,200,200,NULL,NULL,\
           hInst,NULL
	mov   hwnd,eax
	INVOKE ShowWindow, hwnd,SW_SHOWNORMAL
	INVOKE UpdateWindow, hwnd
	.WHILE TRUE
                INVOKE GetMessage, ADDR msg,NULL,0,0
                .BREAK .IF (!eax)
                INVOKE TranslateMessage, ADDR msg
                INVOKE DispatchMessage, ADDR msg
	.ENDW
	mov     eax,msg.wParam
	ret
WinMain endp


end start

Now you're just showing off :p Pretty cool, though :)

One thing I saw was that some don't have a failsafe for division by 0 ;)

So far the examples have been great, it's interesting looking at how each of you approaching parsing the string and splitting into tokens. And I definitely didn't expect to see a windows assembly program :p

Hah, I forgot about null division, but turns out the double-type can divide by zero, you just get 1.#INF :D

@CynicRus

That's amazing one could do something like that with assembler. Do you have any recommended reads for assembler I could tap into? We are programming with MIPS at school.

From: [Re]cUrSivE
@CynicRus

That's amazing one could do something like that with assembler. Do you have any recommended reads for assembler I could tap into? We are programming with MIPS at school.

Well, I think http://www.amazon.com/dp/0471375233/?tag=stackoverfl08-20 or http://www.amazon.com/The-Assembly-Programming-Master-Book/dp/1931769362and http://www.tik.ee.ethz.ch/education/lectures/TI1/materials/assemblylanguageprogdoc.pdf and http://en.wikibooks.org/wiki/Category:MIPS_Assembly.

Alright here's my 25 lines of terror:

#!/usr/bin/perl

use strict;
use warnings;

my %symbols;
my $instructions = <<'END';
--------------------------------------------------------------------
Instructions
--------------------------------------------------------------------
* Enter any mathematical equation to have it solved
* Define symbols with the form $symbols{symbol_name} = symbol_value
* Use symbols with the form $symbols{symbol_name}
--------------------------------------------------------------------
END

sub instructions { print $instructions, 'USER> ' }

instructions;
while (<STDIN>) {
  chomp;
  if ($_ eq 'quit') { print 'Goodbye!'; last }
  elsif ($_ eq 'instructions') { instructions; next }
  print eval, "\nUSER> ";
}

Like I said, more than one way to do it ;)

Basic calculator on the Java Script:)

<SCRIPT LANGUAGE="JavaScript"> 
<!-- Begin
var FKeyPad = document.Keypad;
var Accum = 0;
var FlagNewNum = false;
var PendingOp = "";
function NumPressed (Num) {
if (FlagNewNum) {
FKeyPad.ReadOut.value  = Num;
FlagNewNum = false;
   }
else {
if (FKeyPad.ReadOut.value == "0")
FKeyPad.ReadOut.value = Num;
else
FKeyPad.ReadOut.value += Num;
   }
}
function Operation (Op) {
var Readout = FKeyPad.ReadOut.value;
if (FlagNewNum && PendingOp != "=");
else
{
FlagNewNum = true;
if ( '+' == PendingOp )
Accum += parseFloat(Readout);
else if ( '-' == PendingOp )
Accum -= parseFloat(Readout);
else if ( '/' == PendingOp )
Accum /= parseFloat(Readout);
else if ( '*' == PendingOp )
Accum *= parseFloat(Readout);
else
Accum = parseFloat(Readout);
FKeyPad.ReadOut.value = Accum;
PendingOp = Op;
   }
}
function Decimal () {
var curReadOut = FKeyPad.ReadOut.value;
if (FlagNewNum) {
curReadOut = "0.";
FlagNewNum = false;
   }
else
{
if (curReadOut.indexOf(".") == -1)
curReadOut += ".";
   }
FKeyPad.ReadOut.value = curReadOut;
}
function ClearEntry () {
FKeyPad.ReadOut.value = "0";
FlagNewNum = true;
}
function Clear () {
Accum = 0;
PendingOp = "";
ClearEntry();
}
function Neg () {
FKeyPad.ReadOut.value = parseFloat(FKeyPad.ReadOut.value) * -1;
}
function Percent () {
FKeyPad.ReadOut.value = (parseFloat(FKeyPad.ReadOut.value) / 100) * parseFloat(Accum);
}
</SCRIPT>

Lmao, I built one forever ago in java. Been so long since I've coded in java… damn. It could do summations and a bunch of stuff lol. was really good practice.