Fossil Wrapper

       # alternate name in `commands_spec (e.g., a, ali, alias etc.)
       # generates a further entry (with identical value).
       dict set config::commands $command $fn
    }
}

proc intercept {params} {

    set command [first $params]
    if {[interceptor? $command]} {


        # here, the interceptor definition is retrieved from the
        # `commands' dictionary and used as the anonymous function
        # argument for `apply' (and `params' as its concrete argument). 
        set params [apply [dict get $config::commands $command] $params]
    }
    return $params
}
................................................................................

   return $revnums
}

# --( Fossil )----------------------------------------------------------

proc fossil {args} {
    #if `true' generate some noise:
    set debug false












    set candidate [first $args]; # candidate for expansion



    # Alias expansion and command interception:
    set params [intercept [expand $args]]
    ###puts "final pars: $params"



    if {[empty? $params]} {
        return 0;                # params cleared, no need to run fossil
    }
    set command [first $params]; # expanded candidate

    # Prepare filters:
    set chain [chain_for $candidate]
................................................................................
          }
          # if yes, don't unwrap (but it's still filtered 
          # through `fancy_timeline'. think ...)
          if {!$catmode} {
             set lines [unwrapTimeline $lines]
          }
       }



       foreach line $lines {
          if {$debug == true} {

             puts "IN: >$line<"
             puts -nonewline "OU: >"
             filter_with $chain "$line"
             puts "<"
          } else {
             filter_with $chain "$line"
          }

       # alternate name in `commands_spec (e.g., a, ali, alias etc.)
       # generates a further entry (with identical value).
       dict set config::commands $command $fn
    }
}

proc intercept {params} {
    global dbglvl
    set command [first $params]
    if {[interceptor? $command]} {

        if {$dbglvl > 0} { puts "*** `$command' interceptor triggered" }
        # here, the interceptor definition is retrieved from the
        # `commands' dictionary and used as the anonymous function
        # argument for `apply' (and `params' as its concrete argument). 
        set params [apply [dict get $config::commands $command] $params]
    }
    return $params
}
................................................................................

   return $revnums
}

# --( Fossil )----------------------------------------------------------

proc fossil {args} {
    global dbglvl
    set dbglvl 0

    # check for presence of a `--debug n' option, if present, it
    # defines the debug level which controls how much additional
    # output is generated. after extraction of the debug level the
    # option and its value are eliminated from the argument string
    # since it otherwise would be interpreted as an (unknown) command
    # during further processing.

    set dbgpat {\--debug[[:blank:]]+([[:digit:]]+[ ]*)}
    regexp $dbgpat $args dum dbglvl
    regsub $dbgpat $args "" args

    set candidate [first $args]; # candidate for expansion

    if {$dbglvl > 0} { puts "*** provided argument list: $args" }

    # Alias expansion and command interception:
    set params [intercept [expand $args]]


    if {$dbglvl > 0} { puts "*** expanded argument list: $params" }

    if {[empty? $params]} {
        return 0;                # params cleared, no need to run fossil
    }
    set command [first $params]; # expanded candidate

    # Prepare filters:
    set chain [chain_for $candidate]
................................................................................
          }
          # if yes, don't unwrap (but it's still filtered 
          # through `fancy_timeline'. think ...)
          if {!$catmode} {
             set lines [unwrapTimeline $lines]
          }
       }

       if {$dbglvl == 1} {puts "*** filter chain: $chain"}

       foreach line $lines {

          if {$dbglvl > 2} {
             puts "IN: >$line<"
             puts -nonewline "OU: >"
             filter_with $chain "$line"
             puts "<"
          } else {
             filter_with $chain "$line"
          }