sys.calc()

Purpose:

sys.calc() parses a formula at runtime.

Usage:

ret = sys.calc(<formula>);

Arguments:

<formula> - A string constructed of numeric variables, spaces, operators, parenthesis, and enclosed in curly braces.

Returns:

0 - Formula parsed correctly and result stored in the system variable sys.calc_result.

-1 - Error in parsing - and a message is displayed.

Where Used:

sys.calc() can be called from anywhere.

Example:

formula = "{" + sys.fmt_float(fl1,"99.99-") + "/" +
    sys.fmt_float(fl2,"99.99-") + "}";
sys.calc(formula);
sys.err_msg("Result: " +
    sys.fmt_float(sys.calc_result,"9999.9999-"));

Description:

sys.calc() parses a formula at runtime and sets a result into sys.calc_result. If the string cannot be parsed correctly, sys.calc() returns -1. The value in sys.calc_result is undefined in this case. The formula is a single alpha variable. It can be constructed using the functions max() and min(), arithmetic operators, and parenthesis. The formula must be enclosed in curly braces. Any numeric variables that are part of the formula must converted to alpha and concatenated in the right order.

Bugs/Features/Comments:

No syntax errors can be caught at runtime.

See Also: