Translator – Colon (Design)

The colon token will work very similar to the end-of-line token and so will have the end statement flag in its table entry. The difference with the end-of-line token is that instead of terminating the translation or a line, the token mode will be set to command for the next statement.

There will be two error conditions. Two colons will not be allowed. While a second colon would not affect anything and is allowed in other BASICs, it will be considered an error here. There is no point to allowing this. Also, a colon will not be allowed at the end of the line with no command after it.

When a colon token is received, the colon sub-code will be set in the command token on top of the command stack. The command token will be appended to the end of the statement when the command has been processed (by the command handler).

However, there is an issue with print statements. The actual print command token may not be appended to the output if there is a semicolon, comma or print function at the end of the print statement. In this case, the print command handler will have to transfer the colon sub-code to the last print code that was appended to the output, which may be a print type (when a semicolon is not needed), comma, semicolon, SPC or TAB.