Translator – Associated Codes

Operators and some internal functions allow different operand data types, each will have it's own code (e.g. Add, AddInt, and CatStr), but only one name in the source (e.g. “+”). The Parser will only find the first one in the table since the Parser is only responsible for breaking the source into tokens, not looking at data types and determining appropriate codes. It is the Translator's responsibility to examine and validate the operands of operators and internal functions and to set the token to the appropriate code.

To accomplish this, the first entry in the table (that the Parser finds, the default entry), which for many will be the code that handles the double data type, will contain the other codes associated to the main code. These codes will be put into an associated code array in the table entry.

After obtaining the data types of the operands from the done stack, the Translator will check to see if there is a match to the code by checking the required operand data types in the code's table entry. If there is no match, then each of the associated code table entries will be checked for a match.

In addition to an exact match, there will also be a convertible match. With this type of match, hidden conversion codes can be inserted to obtain the desired data types. The exact match will be preferred so that the correct code is used. For example, if the first exact match or convertible match is used, then for Integer + Integer, the Translator would use the default Add code (for doubles) and add two CvtInt instead of using the preferred AddInt code. Next, how a convertible match will be detected...