Lexical structure

• Identifiers are ASCII only: [A-Za-z_][A-Za-z0-9_]*. A non-ASCII letter where an identifier could start is AES1001. Non-ASCII text is fully supported inside string literals.
• Keywords: package import script type struct enum var const func return if else for switch case default break continue true false nil yield signal coroutine.
• Contextual: start is a keyword only when it is followed by a name and (; elsewhere it is an ordinary identifier. wait, frames and fixed are special only right after yield.
• Reserved for future versions (using them is AES1004): await select go chan defer interface map.
• Literals: integers 10, 0x1f, 1_000; floats 1.5, .5, 1e3, 1_000.5; strings "..." with escapes \n \t \" \\ \uXXXX; true, false, nil. Underscores must separate digits.
• Comments: // line and /* block */. A // comment group directly above a declaration is its documentation and is shown on hover and in completion.
• Semicolons are inserted at a line end after an identifier, literal, ), ], }, return, break, continue, ++, --, or after a > that closes type arguments. Write code line by line as in Go; } followed by else must be on the same line.
• Operators: + - * / % == != < <= > >= && || ! = := += -= *= /= %= ++ --. There are no bitwise operators; a lone & or | is AES1001.

Deliberately unsupported lexical forms (each has a diagnostic that names the intended form):