Language – Define Functions

Before defining what needs to be done with define function tokens in the Translator, a quick review of their syntax is required. The will be two forms of define functions that will be supported, a single line and a multiple line. An example of a single line define function would be:

DEF FNHypot(X,Y)=SQR(X*X+Y*Y)

Notice that this form has the same format as an assignment except for the DEF command at the beginning. The define function token in this statement is FNHypot( - in other words, a define function with parentheses. This implies that a define function with parentheses token could appear in assignment mode (assuming the DEF command sets this mode), but only for the DEF command. An example of the multiple line form of the same function would be:

DEF FNHypot(X,Y)
    FNHypot=SQR(X*X+Y*Y)
END DEF

The assignment of the define function name (a define function without a parentheses) returns the value for the function. Here a define function without a parentheses can appear in an assignment statement, but only inside a DEF/END DEF block. Since the Translator is not aware of blocks, it will permit an assignment of define function without a parentheses token. It will be the Encoder's job to verify if the assignment is valid.