3. Language reference

dflat features

To describe all the features, this reference has been broken in to sections;

• Core language : fundamental commands to define procedures and control program flow
• Definitions : defining and calling procedures
• Variables : some important information about variables and scope
• Flow control : conditional and iteration features
• Basic input/Output : commands to write to the screen, read from keyboard and save/load to tape
• Graphics : commands to assist with graphics, including a software sprite system
• Sound : commands to assist with sound effects
• Assembler : commands to make use of the in-line assembler

Conventions

I have tried to follow some conventions in describing dflat, without being overly formal. Sometimes the syntax is shown by example and other times shown by notation as follows;

• <int> refers to an integer, which can be a constant or an integer variable
• <string> refers to a string, which can be a literal (enclosed in double quotes) or a string variable
• <var> refers to a valid integer variable name
• <var$> refers to a valid string variable name
• <char> refers to a single character (enclosed in single quotes)