Syntax

The surface of the language: lexical structure, literals, string interpolation, doc comments, the call forms and the formatter canon.

What belongs here#

What does not belong here: the meaning of a construct, which belongs to the area it is about. Every page in this folder is a reference page: an example first, then the syntax, then numbered rules, then what the construct is not.

Pages#

• Lexical structure - A statement ends at the end of its line, a name is ASCII while text is not, a block comment ends at its first */, three keywords are never reserved, and a member may be named after a reserved one.
• Literals - An integer, a decimal, a character and a string each have exactly one literal form, and a literal adapts to the type it is expected to have.
• String interpolation - {expression} inside a string runs the expression and shows it, a literal brace is written \{ or \}, and the expression inside the braces has to fit on one line.
• Multi-line strings - A \"\"\" string is dedented by the indentation of its first line with content, so a block of text reads at the indentation of the code around it instead of jammed against the left margin.
• Naming - A name is written in ASCII letters, digits and _, a type starts with an uppercase letter and everything else with a lowercase one, and the compiler reports both at the declaration.
• Angle brackets or comparison - A < after a name starts a type argument list only if what follows parses as types up to a matching > that is itself followed by a token a comparison could not have.
• Doc comments - A /** */ comment attaches to the declaration written directly after it, and everything that can be declared - including a parameter, a field or a case - can have one.
• Syntax cheat sheet - Every form of the language in one place: declarations, expressions, patterns, types and the call rules, with the exact spelling of each.
• Command calls - A call is written without parentheses wherever the grammar allows it, and with parentheses everywhere else. This is the formatter canon and it is enforced, not preferred.