This scriptlet allows channel members to use a trigger to perform a calculation on a formula. For the most part, it checks for valid input and fixes the equation so that the $calc() will not flintch when trying to calculate the requested input.

The standard */+-^() math functions are the only functions that work with this calculator.

;========================================================================
; a channel calculator, by Tsueg
;========================================================================
; List of commands:
;   /calc on         --> turns on the calculator
;   /calc off        --> turns off the calculator
;   /calc <equation> --> performs a private calculation when YOU enter
;                        an equation into an IRC window
;   ~calc <equation> --> performs a calculation when SOMEONE ELSE enters
;                        the '~calc' trigger in the channel
;========================================================================

;========================================================================
; Input Catching
;------------------------------------
#Calculator on
on *:TEXT:~calc &:#: { msg $chan $nick $+ $chr(44) $$2 = $fnCalc($$2) }
#calculator end
;------------------------------------
alias calc {
  if ($1) {
    if ($1 == on) { .enable #calculator | echo -a Calculator has been ENABLED. }
    elseif ($1 == off) { .disable #calculator | echo -a Calculator has been DISABLED. }
    else { echo -a $me $+ $chr(44) $1 = $fnCalc($1) }
  }
  else { echo -a $me $+ $chr(44) error $+ $chr(44) no equation entered. }
}

;========================================================================
; Calculator code
alias -l fnCalc {

  ;---------- Variable Deffinitions ----------
  var %txtFormula = $strip($1)
  var %txtOutput = $null
  var %txtRegex.TestInput  = /([^0-9\.\+\-\*\/\^\(\)])/i
  var %txtRegex.TestOne    = /(\.\.)|(\*\*)|(\/\/)|(\.\*)|(\.\/)|(\*\/)|(\/\*)/i
  var %txtRegex.TestTwo    = /(\.\()|(\.\))|(\(\))|(\(\*)|(\*\))|(\(\/)|(\/\))/i
  var %txtRegex.TestThree  = /(\+\*)|(-\*)|(\+\/)|(-\/)|(\+\+\+)|(\+\+-)|(\+-\+)|(-\+\+)|(\+\--)|(-\+-)|(--\+)|(---)/i
  var %txtRegex.TestFour   = /([0-9][\(]).*[\)]/i
  var %txtRegex.TestFive   = /[\(].*([\)][0-9])/i
  var %txtRegex.TestSix    = /[\(].*([\)][\(]).*[\)]/i
  var %txtRegex.TestSeven  = /(--)/i
  var %txtRegex.TestEight  = /(\+\+)/i
  var %txtRegex.TestNine   = /((\d)+\.(\d)+\.(\d)+)/i
  var %txtRegex.TestTen    = /(\^\^)|(-\^)|(\+\^)|(\/\^)|(\*/^)/i

  ;---------- test for valid input: 0123456789.+-*/^() ----------
  if ($regex(%txtFormula, %txtRegex.TestInput)) {
    %txtOutput = Error $+ $chr(44) bad input: $regml(1)
  }

  ;---------- test for bad bracket counts ----------
  elseif ($count(%txtFormula, $chr(40)) != $count(%txtFormula, $chr(41))) { 
    %txtOutput = Error $+ $chr(44) bracket mismatch.
  }

  ;---------- test for bad operator use: .*/ ----------
  elseif ($regex(%txtFormula, %txtRegex.TestOne)) {
    %txtOutput = Error $+ $chr(44) bad equation: $regml(1)
  }

  ;---------- test for more bad operator use: ^ ----------
  elseif ($regex(%txtFormula, %txtRegex.TestTen)) {
    %txtOutput = Error $+ $chr(44) bad equation: $regml(1)
  }

  ;---------- test for more bad operator use: () ----------
  elseif ($regex(%txtFormula, %txtRegex.TestTwo)) {
    %txtOutput = Error $+ $chr(44) bad equation: $regml(1)
  }

  ;---------- test for more bad operator use: +- ----------
  elseif ($regex(%txtFormula, %txtRegex.TestThree)) {
    %txtOutput = Error $+ $chr(44) bad equation: $regml(1)
  }

  ;---------- test for bad decimal use: #.#.# ----------
  elseif ($regex(%txtFormula, %txtRegex.TestNine)) {
    %txtOutput = Error $+ $chr(44) bad equation: $regml(1)
  }

  ;---------- test for more bracket mismatches: )( ----------
  else {
    var %nbrOpened = 0
    var %nbrClosed = 0
    var %nbrLength = $len(%txtFormula)
    var %LoopCount = 1

    while (%LoopCount <= %nbrLength && %txtOutput == $null) {
      if     ($mid(%txtFormula, %loopCount, 1) == $chr(40)) { .inc %nbrOpened }
      elseif ($mid(%txtFormula, %loopCount, 1) == $chr(41)) { .inc %nbrClosed }

      if (%nbrClosed > %nbrOpened) {
        %txtOutput = Error $+ $chr(44) bracket mismatch.
      }
      .inc %LoopCount
    }
  }

  ;---------- calculate and output the result ----------
  if (%txtOutput == $null) {

    ;---------- check for #( anomalies ----------
    while ($regex(%txtFormula, %txtRegex.TestFour)) {
      %txtFormula = $replace(%txtFormula, $regml(1), $left($regml(1), 1) $+ $chr(42) $+ $chr(40))
    }

    ;---------- check for )# anomalies ----------
    while ($regex(%txtFormula, %txtRegex.TestFive)) {
      %txtFormula = $replace(%txtFormula, $regml(1), $chr(41) $+ $chr(42) $+ $right($regml(1), 1))
    }

    ;---------- check for ). anomalies ----------
    while ($chr(41) $+ $chr(46) isin %txtFormula) {
      %txtFormula = $replace(%txtFormula, $chr(41) $+ $chr(46), $chr(41) $+ $chr(42) $+ $chr(46)) 
    }

    ;---------- check for )( anomalies ----------
    while ($regex(%txtFormula, %txtRegex.TestSix)) {
      %txtFormula = $replace(%txtFormula, $regml(1), $chr(41) $+ $chr(42) $+ $chr(40))
    }

    ;---------- check for -- anomalies ----------
    while ($regex(%txtFormula, %txtRegex.TestSeven)) {
      %txtFormula = $replace(%txtFormula, $regml(1), $chr(43))
    }

    ;---------- check for ++ anomalies ----------
    while ($regex(%txtFormula, %txtRegex.TestEight)) {
      %txtFormula = $replace(%txtFormula, $regml(1), $chr(43))
    }

    ;---------- echo output for debug ----------
    ;    echo -a --> in the calc function, using the equation: %txtFormula

    ;---------- calculate the equation ----------
    %txtOutput = $calc(%txtFormula)
  }

  ;---------- return the result (or error message) ----------
  return %txtOutput
}

;========================================================================