Lexical Conventions

Anvil follows standard lexical rules like SystemVerilog.

Whitespace

Whitespace separates identifiers, literals, and keywords. It is otherwise ignored, except inside string literals, where it forms part of the value.

Comments

Anvil supports two kinds of comments:

Block comments begin with /* and end with */. They may appear inline or span multiple lines.
```
/* This is a block comment */
```
Inline comments start with // and continue to the end of the line.
```
// This is an inline comment
```

Identifiers

Identifiers consist of letters, digits, and underscores, but must start with either a letter or an underscore. In the grammar, non-terminals are prefixed with $.

identifier ::= ( $letter | _ ) { $letter | $digit | _ }
letter     ::= a...z | A...Z
digit      ::= 0...9

Examples of valid identifiers:

counter
_data
temp32

Invalid identifiers:

3value   // cannot start with a digit