#FMCL

Prevents execution of a script more than once per script run.

#FMCL - or 'Function Multi-Call Lock' - is a function that returns false when first encountered in a top-level script execution, then true when encountered subsequent times. It is used by escrow.charge, for example, to ensure it is only called once per script run.

Syntax

#FMCL // false
#FMCL // true
#FMCL // true
// ...

Arguments

#FMCL takes no arguments

Example

Let user.fmcl_test be a hypothetical user script, containing the following code:

function(context, args) {
  if(#FMCL) return "Bruteforcing detected"
  else{
    if(args && args.password == "password1") return "You win!"
    else return "What is my `Npassword`?"
  }
}

If a person attempts to subscript user.fmcl_test to try and bruteforce the password, their first attempt will be processed, but further attempts will be rejected:

function(context, args) {
  return [
    #fs.user.fmcl_test({password:"12345"}),
    #fs.user.fmcl_test({password:"letmein"}),
    #fs.user.fmcl_test({password:"password1"}),
  ]

  // ["What is my `Npassword`?","Bruteforcing detected","Bruteforcing detected"]
}