proc min {a b} { if {$a <= $b} {return $a} {return $b} }
proc max {a b} { if {$a <= $b} {return $b} {return $a} }





proc foreach_ {n FromTos} {
  while {$n} {
    set substs {}
    set indexTo 1
    foreach {From To} $FromTos {
      while {[llength $From] > 0} {
	lappend substs [lindex $From 0] [lindex $To 0]
      
	# Tira o from e o to processados das listas dos caras
	# que falta processar.
	set From [lrange $From 1 end]
	set To [lrange $To 1 end]
      }
    
      # Devolve o "To" comido para a (nova) lista FromTos;
      # avan‡a o ¡ndice que diz de onde o "To" vem.
      set FromTos [lreplace $FromTos $indexTo $indexTo $To]
      incr indexTo 2
    }
    lappend retlist $substs
    incr n -1
  }
  return $retlist
}
# Teste: puts [foreach_ 2 {{a b} {a1 b1 a2 b2} c {c1 c2}}]

proc mysubst_ {str substs} {
  foreach {from to} $substs {
    regsub -all $from $str $to str
  } 
  return $str
}

proc mysubst {str args} { mysubst_ $str $args }
proc runsubst0 {str args} { uplevel #0 [mysubst_ $str $args] }
proc varsubst0 {str args} { uplevel #0 concat [mysubst_ $str $args] }

# "for each substituted version run (at uplevel #0)"
proc fesvr0 {code n args} {
  foreach substs [foreach_ $n $args] {
    uplevel #0 [mysubst_ $code $substs]
  }
}




#
# Rotinas que eu uso pra entender
# como as substitui‡äes funcionam:
#
proc id {x} { return $x }
proc shev {string} {
  puts $string
  puts [concat " => " [eval $string]]
}
proc prev {args} {
  puts \{[join $args \}\ \{]\}
}
proc preve {args} {
  puts \{[join $args \}\ \{]\}
  eval $args
}
set PREV preve




proc v@ {varname default} {
  upvar #0 $varname var
  if {[info exists var]} {puts ex; return $var} {puts nex; return $default}
}



# Globais: oldx oldy deltax deltay

set oldx 0
set oldy 0

proc getdeltas {newx newy} {
  global oldx oldy deltax deltay
  set deltax [expr $newx - $oldx]
  set deltay [expr $newy - $oldy]
  set oldx $newx
  set oldy $newy
  return "$deltax $deltay"
}




# (find-tkexfile "items.tcl" "<3>")
# O retƒngulo ‚ chamado de "area".
# Como eu nÆo scrollo eu tirei os [canvasx ...], [canvasy ...].

# set corner1 "0 0"
# set corner2 "0 0"

# bind .c <B2-ButtonPress> { {%x %y}}  
# bind .c <2> "anchorRect $c %x %y"  
# bind .c <B2-Motion> "dragRect $c %x %y"
# bind .c <B2-ButtonRelease> "set B2Down 0"

# proc anchorRect {c x y} {
#   global RectX1 RectY1 B2Down
#   puts "anch $x $y"
# # if {$B2Down == 0} {
#     set RectX1 $x
#     set RectY1 $y
#     $c delete Rect
#     set B2Down 1
# # }
# }
# proc dragRect {c x y} {
#   global RectX1 RectX2 RectY1 RectY2
#   puts "drag $x $y"
#   .c delete Rect
#   .c create rect $RectX1 $RectY1 $x $y -tag Rect -outline black
#   set RectX2 $x
#   set RectY2 $y
# }


# (find-fline "/usr/local/lib/tcltutor/lessons/")
# (find-fline "/usr/src/TclTutor/")
# (find-esfile "tcl.e" "# TclTutor")
# (find-fline "/usr/local/bin/QuizChecker.tcl")
# (find-fline "/usr/local/bin/TclTutor.tk")
# (find-fline "/usr/local/bin/TclTutor.tk" "Widgets.tk")
# (find-fline "/usr/local/bin/TclTutor.tk" " RunCode ")