Whitespace and comments

In general, cQASM is not whitespace-sensitive, apart from newlines. Spaces and tabs can be placed in between tokens.

Comments can be written as single-line comments or as multi-line comments within a comment block. Only comments can appear before the version statement. Whitespace before a single-line or multi-line comment is permitted.

Single-line comment

A single-line comment is prefixed by two forward slashes // and finishes with the new line, equal to the syntax of C-like languages.

The general form of single-line comments is as follows

 // single-line-comment
 statement
 statement // single-line-comment

Example

// This is a single-line comment, which ends on the new line.
H q[0]
CNOT q[0], q[1]  // A single-line comment can follow a statement.

Multi-line comments

Multi-line comment blocks allow for writing comments that span multiple lines. A comment block starts with the combination of a forward slash and an asterisk /* and end with the combination of an asterisk and a forward slash */.

The general structure of a multi-line comment is given by

 /* multi-line
 comment-block */

 statement /* multi-line
 comment-block */ statement

An example of multi-line commenting is given by the following:

Example

/* This is a multi-
line comment. */
CNOT q[0], /* A comment block can
be placed in between tokens. */ q[1]

A pair of forward slashes // may be part of a multi-line comment block. In that case they are considered part of the comment and not the start of a single-line comment.