Exception: Exception

Defined in:
lib/core/facets/exception/detail.rb,
lib/core/facets/exception/raised.rb,
lib/core/facets/exception/suppress.rb,
lib/core/facets/exception/error_print.rb,
lib/core/facets/exception/set_message.rb

Direct Known Subclasses

Lazy::DivergenceError

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.error_print(e) ⇒ Object

Formats the Exception so that it looks familiar, i.e. exactly like your interpreter does it.

Port of MRI native error_print function.



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# File 'lib/core/facets/exception/error_print.rb', line 10

def self.error_print(e)
  warn_print = ""
  backtrace = e.backtrace
  backtrace = [ backtrace ] if backtrace.is_a?(String) # 1.9 returns single String for SystemStackError

  warn_print << backtrace[0]
  if e.is_a?(RuntimeError) && e.message.empty?
    warn_print << ": unhandled exception\n"
  else
    if e.message.empty?
      warn_print << ": #{ e.class.name }\n"
    else
      split_message = e.message.split("\n")
      warn_print << ": "
      if split_message.size == 1
        warn_print << "#{ e.message } (#{ e.class.name })\n"
      else
        warn_print << split_message[0]
        warn_print << " (#{ e.class.name })\n"
        warn_print << split_message[1..-1].join("\n").chomp << "\n"
      end
    end
  end

  len = backtrace.size

  ## int skip = eclass == rb_eSysStackError;
  skip = e.is_a?(SystemStackError)

  ## #define TRACE_MAX (TRACE_HEAD+TRACE_TAIL+5)
  ## #define TRACE_HEAD 8
  ## #define TRACE_TAIL 5
  trace_head = 8
  trace_tail = 5
  trace_max = (trace_head + trace_tail + 5)
  ##
  ##  for (i = 1; i < len; i++) {
  i = 1
  while i < len
    ##      if (TYPE(ptr[i]) == T_STRING) {
    ##    warn_printf("\tfrom %s\n", RSTRING_PTR(ptr[i]));
    ##      }
    warn_print << "\tfrom %s\n" % e.backtrace[i]

    ##      if (skip && i == TRACE_HEAD && len > TRACE_MAX) {
    if skip && i == trace_head && len > trace_max
    ##    warn_printf("\t ... %ld levels...\n",
    ##          len - TRACE_HEAD - TRACE_TAIL);
      warn_print << "\t ... %d levels...\n" % (len - trace_head - trace_tail)
    ##    i = len - TRACE_TAIL;
      i = len - trace_tail
    ##      }
    end
    ##  }
    i += 1
  end
  warn_print
end

.raised? ⇒ Boolean

Does a block raise an a given exception.

Returns:



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# File 'lib/core/facets/exception/raised.rb', line 5

def self.raised? #:yeild:
  begin
    yield
    false
  rescue self
    true
  end
end

.suppress(*exception_classes) ⇒ Object

Supress errors while executing a block, with execptions.

CREDIT: David Heinemeier Hansson, Thomas Sawyer



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# File 'lib/core/facets/exception/suppress.rb', line 7

def self.suppress(*exception_classes)
  exception_classes.each do |e|
    unless e < self
      raise ArgumentError, "exception #{e} not a subclass of #{self}"
    end
  end
  exception_classes = [self] | exception_classes
  begin
    yield
  rescue Exception => e
    raise unless exception_classes.any? { |cls| e.kind_of?(cls) }
  end
end

Instance Method Details

#detail ⇒ Object

Pretty string output of exception/error object useful for helpful debug messages.



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# File 'lib/core/facets/exception/detail.rb', line 8

def detail
  if backtrace
    %{#{self.class.name}: #{message}\n  #{backtrace.join("\n  ")}\n  LOGGED FROM: #{caller[0]}}
  else
    %{#{self.class.name}: #{message}\n  LOGGED FROM: #{caller[0]}}
  end
end

#error_print ⇒ Object

TODO:

Anyone have a better name for this method?

Formats the Exception so that it looks familiar, i.e. exactly like your interpreter does it.



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# File 'lib/core/facets/exception/error_print.rb', line 75

def error_print
  Exception.error_print(self)
end

#set_message(string) ⇒ Object

See exception message.



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# File 'lib/core/facets/exception/set_message.rb', line 5

def set_message(string)
  @mesg = string.to_s
end