UCALC equivalent

[John Machin]

Scott David Daniels wrote:
> max wrote:
> 
>> Larry Bates <lbates at syscononline.com> wrote in
>> news:42FCDCA7.7030107 at syscononline.com:
>>
>>> Python has built in eval function and doesn't require a library.
>>
>>
>> Are you kidding? Read the original post a little more closely. The 
>> o.p. is looking for a library that evaluates mathematical expressions 
>> and is callable from python code.
> 
> 
> He is absolutely correct.
>  From the web page referenced:
> 
>     ucDefineFunction("area(length,width) = length*width");
>     ucDefineFunction("frac(x)=abs(abs(x)-int(abs(x)))");
>     ucDefineFunction("test() = 5");
>     ucDefineFunction("abc(x, y=10) = x + y");
>     ucDefineFunction("shl[x, y] = x * 2^y");
> 
>     cout.precision(16);
>     cout << ucEval("frac(150/17) * area(20,30)") << endl;
>     cout << ucEval("abc(5)-abc(3,4)*(#b01101 shl 1)")
>          << endl;
> 
> 
> The python equivalent:
> 
>     exec "def area(length,width): return length*width"
>     exec "def frac(x): return abs(abs(x) - int(abs(x)))"
>     exec "def test(): return 5"
>     exec "def abc(x, y=10): return x + y"
>     exec "def shl(x, y): return x * 2^y"

Perhaps this should be:
exec "def shl(x, y): return x * 2 ** y"
or
exec "def shl(x, y): return x << y"

> 
>     print eval("frac(150/17) * area(20,30)")
>     print eval("abc(5) - abc(3,4) * shl(0x0E, 1)")
> 
> --Scott David Daniels
> Scott.Daniels at Acm.Org