Source code representation

Script source is text. The character set is ASCII: each byte is a character, with no Unicode or multibyte decoding. Source characters fall into a small number of classes — letters, digits, whitespace, and line terminators.

Characters

The character classes are:

• Whitespace: Space (' ') and tab ('\t') separate adjacent tokens and are otherwise insignificant. Newlines are not whitespace — they are statement separators (see below).
• Line terminators: A line feed ('\n'), a carriage return ('\r'), or a carriage return followed by a line feed ("\r\n") terminates a source line. Any of these three forms counts as a single newline, which acts as a statement separator (see below).
• Letters: A ... Z and a ... z.
• Digits: 0 ... 9

Source layout

A script is free-form: statements are separated by newlines or semicolons, which are equivalent (see Lexical elements — Statement separators).

A backslash \\immediately before a line terminator is a line continuation: the backslash and the terminator are both removed, joining the two physical lines into one logical line. This is the only way to spread a single statement across multiple physical lines outside of a delimited construct (inside [...], (...), and {...} newlines are already absorbed as ordinary separators or whitespace).

Comments

A comment begins with # and runs to the end of the line. The # may appear anywhere a token may begin, including after code on the same line. The line terminator that ends a comment is retained and still acts as a statement separator.

# a full-line comment
do "wave"          # a trailing comment

# is not a bareword character, so it cannot be embedded in an identifier; a # that is intended literally must appear inside a string (Lexical elements — String literals).