Interactive LET Query: LET ECHO

The LET ECHO facility shows how FOCUS interprets FOCUS statements. This facility is a diagnostic tool you can use when statements containing LET-defined words are not being interpreted the way you expect them to.

When the LET ECHO facility is activated, when you enter a FOCUS statement, LET ECHO displays the statement as interpreted by FOCUS.

Syntax: How to Activate the LET ECHO Facility

To activate the LET ECHO facility, issue the command:

LET ECHO

Syntax: How to Deactivate the LET ECHO Facility

ENDECHO

Reference: Results of LET ECHO Commands

The following explains the results of a LET ECHO command:

If you enter a statement containing no LET-defined words, LET ECHO displays the statement as you entered it.
If you enter a statement containing LET-defined words, LET ECHO displays the statement with the substitutions made.
If the statement contains variable substitutions, LET ECHO displays the substitutions with the placeholders filled in.
If the statement contains multiple-line substitutions, LET ECHO displays the statement with the substitutions on multiple lines.
If the statement contains null substitutions, LET ECHO displays the statement with the LET-defined words deleted.
If the statement contains recursive substitutions, the substitutions appear as they are finally resolved.
LET ECHO may be coded as the first line of a FOCEXEC and ENDECHO as the last line.

Note: If you enter a statement containing a variable substitution, you must enter as many words after the LET-defined word as there are placeholders in the phrase; otherwise, LET ECHO will wait for additional input.