Settlang

Documents

Settlang is a statically typed programming language that expresses mutability by whether variables have setters.

Basic grammar and concepts are follow. See examples for details!

Type

• i32 : 32-bit signed integer
• i64 : 64-bit signed integer
• string : surrounded by ", can be used as a first argument of 'print' / 'println'

Expression

• arithmetric -> +, -, *, /, %
• compare -> ==, !=, <, <=, >=, >
• logical AND &&, logical OR ||

Variable

'let' varname ':' typename ('|' setter function name)? '=' expr

Setter is a funcion that returns new value of the variable. The return value type of setter and variablue type must match.

Standad library

• print(string, ...) -> void
• append string to output area
• println(string, ...) -> void
• append string to output area and break line
• alert(string, ...) -> void
• call window.alert()
• read(void) -> i64
• get input from user by using window.prompt()
• random(i64, i64) -> i64
• return random value (first args <= return value <= second args)