Undocumented Tcl 8.5 Issue

As most know Cloverleaf 6.0+ uses Tcl 8.5 while previous versions used Tcl 8.4.

For years one of my “Soapbox” issues has been to treat lists as lists and strings as strings.  Tcl 8.5 makes that even more important.

The lrange command will return a *LIST* though some treat it as a string

In Tcl 8.4 you see the following:

tcl>set lst

A # B

tcl>lrange $lst 1 1

#

However in Tcl 8.5+ it becomes:

tcl>set lst

A # B

tcl>lrange $lst 1 1

{#}

If you attempt to do commands like regexp, string equal, etc against the results it will give you different results.  Note that {*} is a legitimate list with one value.  This quoting seems to occur with special characters

If you really want to treat the results as a string, first convert to string:

regexp — {#} [lindex [lrange $lst 1 1] 0]  OR

regexp — {#} [join [lrange $lst 1 1]]

You may have to modify 8..4 scripts if this applies.