Appendix A: Keywords

The following list contains keywords that are reserved for current or future use by Calyxium. As such, they cannot be used as identifiers. Identifiers are names of functions, variables, parameters, structs fields, modules, types.

Keywords Currently in Use

The following is a list of keywords currently in use, with their functionality described.

• rec - define a recursive function
• if - branch based on the result of a conditional expression
• then - fallback for if control flow constructs
• else - fallback for then and if control flow constructs
• let - bind a variable or function
• match - match a value to patterns
• with - branch based on the value of match
• use - in a module path, refers to the modules root
• mod - define a module
• true - Boolean true literal
• false - Boolean false literal
• type - define a ADT/record, and enumeration
• fn - define a anonymous functions, lambda abstraction

Deprecated keywords

• for - loops over items Superseded by rec

Keywords Reserved for Future Use

The following keywords do not yet have any functionality but are reserved by Calyxium for potential future use.

• class
• extends
• ref