Exception: KeyError

Inherits:
IndexError show all
Defined in:
error.c,
error.c

Overview

Raised when the specified key is not found. It is a subclass of IndexError.

h = {"foo" => :bar}
h.fetch("foo") #=> :bar
h.fetch("baz") #=> KeyError: key not found: "baz"

Instance Method Summary collapse

Methods inherited from Exception

#==, #backtrace, #backtrace_locations, #cause, #exception, exception, #full_message, #inspect, #message, #set_backtrace, #to_s, to_tty?

Constructor Details

#new(message = nil, receiver: nil, key: nil) ⇒ Object

Construct a new KeyError exception with the given message, receiver and key.



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# File 'error.c', line 1938

static VALUE
key_err_initialize(int argc, VALUE *argv, VALUE self)
{
    VALUE options;

    rb_call_super(rb_scan_args(argc, argv, "01:", NULL, &options), argv);

    if (!NIL_P(options)) {
	ID keywords[2];
	VALUE values[numberof(keywords)];
	int i;
	keywords[0] = id_receiver;
	keywords[1] = id_key;
	rb_get_kwargs(options, keywords, 0, numberof(values), values);
	for (i = 0; i < numberof(values); ++i) {
	    if (values[i] != Qundef) {
		rb_ivar_set(self, keywords[i], values[i]);
	    }
	}
    }

    return self;
}

Instance Method Details

#key ⇒ Object

Return the key caused this KeyError exception.

Returns:



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# File 'error.c', line 1909

static VALUE
key_err_key(VALUE self)
{
    VALUE key;

    key = rb_ivar_lookup(self, id_key, Qundef);
    if (key != Qundef) return key;
    rb_raise(rb_eArgError, "no key is available");
}

#receiver ⇒ Object

Return the receiver associated with this KeyError exception.

Returns:



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# File 'error.c', line 1892

static VALUE
key_err_receiver(VALUE self)
{
    VALUE recv;

    recv = rb_ivar_lookup(self, id_receiver, Qundef);
    if (recv != Qundef) return recv;
    rb_raise(rb_eArgError, "no receiver is available");
}