OpenEuphoria

1. Parsing calculator

• Posted by Fendaril Sep 18, 2009
• 1244 views

Hey guys. I worked on a little project that outputs the value of two terms with a specified operator. It parses so you can enter in '1+1,29873/2,467384*2 and etc....'. If anyone is interested try it out.

include get.e 
include std/convert.e 
 
constant TRUE=1 
constant FALSE=0 
constant ADDITION=2 
constant SUBTRACTION=3 
constant MULTIPLY=4 
constant DIVIDE=5 
atom found=0 
sequence sFirstPart="" 
sequence sSecondPart="" 
atom operationType=0 
 
procedure add(atom SymbolLocation,atom operation) 
	for i=1 to SymbolLocation-1 do 
		sFirstPart=append(sFirstPart,equation[i]) 
	end for 
	 
	for i=SymbolLocation+1 to length(equation) do 
		sSecondPart=append(sSecondPart,equation[i]) 
	end for 
 
if operation=ADDITION then 
?to_number(sFirstPart)+to_number(sSecondPart) 
elsif operation=SUBTRACTION then 
?to_number(sFirstPart)-to_number(sSecondPart) 
elsif operation=MULTIPLY then 
?to_number(sFirstPart)*to_number(sSecondPart) 
elsif operation=DIVIDE then 
?to_number(sFirstPart)/to_number(sSecondPart) 
else 
puts(1,"ERROR") 
end if 
end procedure 
 
sequence equation=prompt_string("Enter your equation: ") 
for i=1 to length(equation)-1 do 
	if equation[i]='+' then 
		found=TRUE 
		operationType=ADDITION 
		add(i,operationType) 
	elsif equation[i]='-' then 
		found=TRUE 
		operationType=SUBTRACTION 
		add(i,operationType) 
	elsif equation[i]='*' then 
		found=TRUE 
		operationType=MULTIPLY 
		add(i,operationType) 
	elsif equation[i]='/' then 
		found=TRUE 
		operationType=DIVIDE 
		add(i,operationType) 
	end if 
end for 
if found=FALSE then 
	--person tried to be a wise guy >.> 
	puts(1,"Invalid equation\n") 
end if