#
#--
# e2mmap.rb - for Ruby 1.1
# $Release Version: 2.0$
# $Revision: 1.10 $
# by Keiju ISHITSUKA
#
#++
#
# Helper module for easily defining exceptions with predefined messages.
#
# == Usage
#
# 1.
# class Foo
# extend Exception2MessageMapper
# def_e2message ExistingExceptionClass, "message..."
# def_exception :NewExceptionClass, "message..."[, superclass]
# ...
# end
#
# 2.
# module Error
# extend Exception2MessageMapper
# def_e2message ExistingExceptionClass, "message..."
# def_exception :NewExceptionClass, "message..."[, superclass]
# ...
# end
# class Foo
# include Error
# ...
# end
#
# foo = Foo.new
# foo.Fail ....
#
# 3.
# module Error
# extend Exception2MessageMapper
# def_e2message ExistingExceptionClass, "message..."
# def_exception :NewExceptionClass, "message..."[, superclass]
# ...
# end
# class Foo
# extend Exception2MessageMapper
# include Error
# ...
# end
#
# Foo.Fail NewExceptionClass, arg...
# Foo.Fail ExistingExceptionClass, arg...
#
#
module Exception2MessageMapper
E2MM = Exception2MessageMapper # :nodoc:
def E2MM.extend_object(cl)
super
cl.bind(self) unless cl < E2MM
end
def bind(cl)
self.module_eval %[
def Raise(err = nil, *rest)
Exception2MessageMapper.Raise(self.class, err, *rest)
end
alias Fail Raise
def self.included(mod)
mod.extend Exception2MessageMapper
end
]
end
# Fail(err, *rest)
# err: exception
# rest: message arguments
#
def Raise(err = nil, *rest)
E2MM.Raise(self, err, *rest)
end
alias Fail Raise
alias fail Raise
# def_e2message(c, m)
# c: exception
# m: message_form
# define exception c with message m.
#
def def_e2message(c, m)
E2MM.def_e2message(self, c, m)
end
# def_exception(n, m, s)
# n: exception_name
# m: message_form
# s: superclass(default: StandardError)
# define exception named ``c'' with message m.
#
def def_exception(n, m, s = StandardError)
E2MM.def_exception(self, n, m, s)
end
#
# Private definitions.
#
# {[class, exp] => message, ...}
@MessageMap = {}
# E2MM.def_e2message(k, e, m)
# k: class to define exception under.
# e: exception
# m: message_form
# define exception c with message m.
#
def E2MM.def_e2message(k, c, m)
E2MM.instance_eval{@MessageMap[[k, c]] = m}
c
end
# E2MM.def_exception(k, n, m, s)
# k: class to define exception under.
# n: exception_name
# m: message_form
# s: superclass(default: StandardError)
# define exception named ``c'' with message m.
#
def E2MM.def_exception(k, n, m, s = StandardError)
n = n.id2name if n.kind_of?(Fixnum)
e = Class.new(s)
E2MM.instance_eval{@MessageMap[[k, e]] = m}
k.const_set(n, e)
end
# Fail(klass, err, *rest)
# klass: class to define exception under.
# err: exception
# rest: message arguments
#
def E2MM.Raise(klass = E2MM, err = nil, *rest)
if form = e2mm_message(klass, err)
b = $@.nil? ? caller(1) : $@
b.shift if b[0] =~ /^#{Regexp.quote(__FILE__)}:/
raise err, sprintf(form, *rest), b
else
E2MM.Fail E2MM, ErrNotRegisteredException, err.inspect
end
end
class << E2MM
alias Fail Raise
end
def E2MM.e2mm_message(klass, exp)
for c in klass.ancestors
if mes = @MessageMap[[c,exp]]
m = klass.instance_eval('"' + mes + '"')
return m
end
end
nil
end
class << self
alias message e2mm_message
end
E2MM.def_exception(E2MM,
:ErrNotRegisteredException,
"not registered exception(%s)")
end
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