Re: Best way to set up a dict of defaults?

On 4 Sep., 16:50, Twylite <twylite.cr...@xxxxxxxxx> wrote:
But some of the default values are calculated/derived rather than
static (say based on the name of the application, $argv0). What is
the best way for me to set up these defaults?

I current use list, which is ugly because of line continuation:
set app_path [file dirname $argv0]
set app_base_name [file tail [file rootname $argv0]]
set prefs_defaults [list \
log.file [file join $app_path "data" "${app_base_name}.log"] \
log.level WARN \
]

Subst appears to be a solution, but can trick the unwary:
set prefs_defaults [subst {
log.file [file join $app_path "data" "${app_base_name}.log"]
log.level WARN
}]

Notice that this will work correctly only so long as the resulting
file path contains no spaces, otherwise you will get e.g.
log.file C:/Program Files/MyApp/data/myapp.log
which is 3 elements instead of 2 ;(

Yes - one advantage of [list] is that it braces properly.

Am I missing something obvious; is there a better way?

How about building the list that will become the dict in multiple
steps:

set prefs_defaults {
log.level WARN
foo BAR
} ;# initially: all the simple constant cases

#--- then add those that need variables and commands:
lappend prefs_defaults log.file [file join $app_path "data" "$
{app_base_name}.log"]
...

.

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