INPUT Execution Codes - Parsing

The parsing of the entered input values must be done separately from the assignment of the values entered to the input variables. This a departure from the design previously described and is due to the two input rules. For the example, this is steps 3 through 6. Notice that after a value is parsed (steps 3 and 5), a check is made for the next character. This character must be a comma after each value except for the last value where an end-of-line (no character) is expected.

There will be a code to parse an input value for each data type: InputParseInt, InputParseDbl and InputParseStr. An 'End' sub-code will be set on the last parse code. If this sub-code is not set, then the next character must be a comma, otherwise an end-of-line (no character) is expected.

The values that are parsed need to be put somewhere. If input values were pushed on to the evaluation stack, then when the references to the input variables are pushed, the input values would be down the stack and would not be easily accessible. Therefore, the evaluation stack can't be used.