The print operation writes a text message to standard output and then returns
that same message as its result. It is useful for emitting informational or
success messages from within a Gendo pipeline while preserving the pipeline’s
data flow.
The syntax of the print operation is:
[ $destination ] print [ message ]
Both $destination and message are optional. If neither is provided, print
writes the current value of _ to stdout, rebinds _ to that same value, and
continues. If you supply a message, you must also supply a $destination to
bind it; if you omit $destination, _ is assumed implicitly.
For example, to print and continue using _:
This writes the value in _ to stdout and leaves it unchanged.
To print a literal and bind it to _:
_ print “Compilation succeeded.”
This writes “Compilation succeeded.” to stdout and binds that text to _.
To bind the printed message to a named identifier:
$status let “All tests passed.” $status print $status
This writes “All tests passed.” to stdout and leaves status bound to that
message.
The print operation does not alter its input values. It returns the same text
it writes, enabling subsequent operations to consume it. If a provided
message is not a string, the operation results in a runtime error. All
identifiers follow single‑assignment rules.