Try-Catch

Try

A simple try block (catches and ignores the error):

try
  this.doSomething()
end

Shortened to:

try : this.doSomething()

Example:

i int
try : i = int.parse("twenty")

Try-Catch

Handling the error:

try
  this.doSomething()
catch e Error
  Console.log(e)
end

Shortened to:

try : this.doSomething()
catch e Error : Console.log(e)

Multiple types of errors

try
  arg = this.doSomethingA()
  this.doSomethingB(arg)
catch e InvalidArgumentError
  Console.log("Argument was invalid")
catch e Error
  Console.log("Something else went wrong")
end

Or shorter

try
  arg = this.doSomethingA()
  this.doSomethingB(arg)
catch e InvalidArgumentError : Console.log("Argument was invalid")
catch e Error : Console.log("Something else went wrong")

Finally

try
  this.doSomething()
catch e Error
  Console.log(e)
finally
  this.cleanup()
end

Shortened to:

try : this.doSomething()
catch e Error : Console.log(e)
finally : this.cleanup()

Throwing Errors

throw new NotImplementedError()

Provide an error text

if x > 100 : throw new ArgumentOutOfRangeError("x must be in the range of 0 to 100")

Rethrowing (stacktrace will change):

try
  this.doSomethingA()
  this.doSomethingB()
catch e Error
  throw e
end

Or shorter:

try
  this.doSomethingA()
  this.doSomethingB()
catch e Error : throw e

Wrapping an error (cause):

try
  this.doSomething()
catch e Error
  throw new MyCustomError("Something went wrong", e)
end

Custom Error Classes

For more custom error classes extend from Error base class

package MyLib

using LimaScript

class MyCustomError extends Error
  constructor(code int)
    Console.log(code)
  end
end