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Exception: NameError

Relationships & Source Files
Namespace Children
Classes:
message
Extension / Inclusion / Inheritance Descendants
Subclasses:
NoMethodError
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::StandardError, ::Exception
Instance Chain:
self, ::StandardError, ::Exception
Inherits: StandardError
Defined in: error.c,
error.c

Overview

Raised when a given name is invalid or undefined.

puts foo

raises the exception:

NameError: undefined local variable or method `foo' for main:Object

Since constant names must start with a capital:

Integer.const_set :answer, 42

raises the exception:

NameError: wrong constant name answer

Class Attribute Summary

::Exception - Inherited

.to_tty?

Returns true if exception messages will be sent to a terminal device.

Class Method Summary

::Exception - Inherited

.exception

Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
.new

Returns a new exception object.

Instance Method Summary

::Exception - Inherited

#==

Returns whether object is the same class as self and its #message and #backtrace are equal to those of self.
#backtrace

Returns the backtrace (the list of code locations that led to the exception), as an array of strings.
#backtrace_locations

Returns the backtrace (the list of code locations that led to the exception), as an array of ::Thread::Backtrace::Location instances.
#cause

Returns the previous value of global variable $!, which may be nil (see Global Variables):
#detailed_message

Returns the message string with enhancements:
#exception

Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
#full_message

Returns an enhanced message string:
#inspect

Returns a string representation of self:
#message

Returns #to_s.
#set_backtrace

Sets the backtrace value for self; returns the given value.
#to_s

Returns a string representation of self:

Constructor Details

.new(msg = nil, name = nil, receiver: nil) ⇒ name_error

Construct a new NameError exception. If given the name parameter may subsequently be examined using the #name method. receiver parameter allows to pass object in context of which the error happened. Example:

[1, 2, 3].method(:rject) # NameError with name "rject" and receiver: Array
[1, 2, 3].singleton_method(:rject) # NameError with name "rject" and receiver: [1, 2, 3]
[ GitHub ] 

  


# File 'error.c', line 2400



static VALUE
name_err_initialize(int argc, VALUE *argv, VALUE self)
{
    ID keywords[1];
    VALUE values[numberof(keywords)], name, options;

    argc = rb_scan_args(argc, argv, "*:", NULL, &options);
    keywords[0] = id_receiver;
    rb_get_kwargs(options, keywords, 0, numberof(values), values);
    name = (argc > 1) ? argv[--argc] : Qnil;
    rb_call_super(argc, argv);
    name_err_init_attr(self, values[0], name);
    return self;
}


  







Instance Method Details



  

    #local_variables  ⇒ Array   



  

    

Return a list of the local variable names defined where this NameError exception was raised.



Internal use only.


  



  [ GitHub ]


  

  


# File 'error.c', line 2454



static VALUE
name_err_local_variables(VALUE self)
{
    VALUE vars = rb_attr_get(self, id_local_variables);

    if (NIL_P(vars)) {
        VALUE iseqw = rb_attr_get(self, id_iseq);
        if (!NIL_P(iseqw)) vars = rb_iseqw_local_variables(iseqw);
        if (NIL_P(vars)) vars = rb_ary_new();
        rb_ivar_set(self, id_local_variables, vars);
    }
    return vars;
}


  








  

    #name  ⇒ String?   



  

    

Return the name associated with this NameError exception.


  



  [ GitHub ]


  

  


# File 'error.c', line 2438



static VALUE
name_err_name(VALUE self)
{
    return rb_attr_get(self, id_name);
}


  








  

    #receiver  ⇒ Object   



  

    

Return the receiver associated with this NameError exception.


  



  [ GitHub ]


  

  


# File 'error.c', line 2739



static VALUE
name_err_receiver(VALUE self)
{
    VALUE recv = rb_ivar_lookup(self, id_recv, Qundef);
    if (!UNDEF_P(recv)) return recv;

    VALUE mesg = rb_attr_get(self, id_mesg);
    if (!rb_typeddata_is_kind_of(mesg, &name_err_mesg_data_type)) {
        rb_raise(rb_eArgError, "no receiver is available");
    }

    name_error_message_t *ptr;
    TypedData_Get_Struct(mesg, name_error_message_t, &name_err_mesg_data_type, ptr);
    return ptr->recv;
}