Fossil Wrapper

#!/usr/bin/env expect
# -*-tcl-*-
#
# Copyright (c) 2012, Marc Simpson <marc@0branch.com> (ISC, see LICENSE)

# --( Aliases and Filters )---------------------------------------------

namespace eval config {
    set dbglvl 0;               # debug level

    set aliases {}
    set filters {};             # registered filters
    set commands {};            # registered interceptors

    proc init {filename} {
        set myname $::argv0
        if {[file exists $filename] && [file mtime $filename] > [file mtime $myname]} {

}

proc preparse argv {
# -------------------------------------------------------------------
# purpose: preprocessing of provided argument string by looking
# for `fsl' specific option/value arguments, which are eliminated
# from the argv string after the corresponding actions are performed.
#
# currently understands the following options:
#
#    --debug n : set variable `config::dbglvl' to value n
# -------------------------------------------------------------------


  
   # 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 $argv dum config::dbglvl
   regsub $dbgpat $argv "" argv

   return $argv
}

# --( Interceptors )----------------------------------------------------

   #replace `-r n:m' by the constructed `diff' arguments: 
   regsub $revarg $params $from$to params
   return $params
}

proc intercept {params} {

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

        if {$config::dbglvl > 0} { puts "*** `$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
}

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

proc fossil {args} {


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

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

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

    if {$config::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:

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

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

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