scripts/expression.itcl

   1 # vim: foldmarker=<<<,>>>
   2
   3 class tlc::Expression {
   4         inherit tlc::Signal
   5
   6         constructor {accessvar args} {
   7                 upvar $accessvar scopevar
   8                 eval tlc::Signal::constructor scopevar
   9         } {}
  10
  11         public {
  12                 variable panic  0
  13
  14                 method set_expression {rawexpr}
  15                 method reassess {args}
  16                 method add_term {var_ref}
  17         }
  18
  19         private {
  20                 variable expression     {}
  21                 variable dominos
  22         }
  23 }
  24
  25
  26 body tlc::Expression::constructor {accessvar args} { #<<<1
  27         array set dominos       {}
  28
  29         tlc::Domino #auto dominos(need_reassess) -name "$name need_reassess"
  30         $dominos(need_reassess) attach_output [code $this reassess]
  31
  32         eval configure $args
  33 }
  34
  35
  36 body tlc::Expression::set_expression {rawexpr} { #<<<1
  37         set map         {
  38                 [       \\[
  39                 ]       \\]
  40                 $       \\$
  41                 %[      {\[code [list $this] }
  42                 %]      {\]}
  43                 %<      {\[set [list [scope }
  44                 %>      {]]\]}
  45                 %(      {[list [scope }
  46                 %)      {]]}
  47         }
  48         set expression  [string map $map $rawexpr]
  49         debug trivia "processed first stage expression: ($expression)"
  50         set expression  [uplevel [list subst $expression]]
  51         debug trivia "processed second stage expression: ($expression)"
  52         reassess
  53 }
  54
  55
  56 body tlc::Expression::reassess {args} { #<<<1
  57         if {[catch {
  58                 set_state [expr $expression]
  59                 debug debug "Reassessing ($name) == [state]\n$expression\n----------------\n[subst $expression]"
  60         }]} {
  61                 debug debug "Error assessing expression ($name): ($::errorInfo)"
  62                 set_state 0
  63                 error "Error assessing expression ($name): ($::errorInfo)"
  64         }
  65 }
  66
  67
  68 body tlc::Expression::add_term {var_ref} { #<<<1
  69         tlc::Vardomino #auto dominos($var_ref) -name "$name term $var_ref" \
  70                         -textvariable $var_ref
  71         $dominos(need_reassess) attach_input $dominos($var_ref)
  72 }
  73
  74