Module: Warning
Overview
The Warning module contains a single method named #warn, and the module extends itself, making #warn available. #warn is called for all warnings issued by Ruby. By default, warnings are printed to $stderr.
By overriding #warn, you can change how warnings are handled by Ruby, either filtering some warnings, and/or outputting warnings somewhere other than $stderr. When #warn is overridden, super can be called to get the default behavior of printing the warning to $stderr.
Class Method Summary
-
.[](category) ⇒ Boolean
Returns the flag to show the warning messages for
category. -
.[]=(category, flag) ⇒ flag
Sets the warning flags for
category.
Instance Method Summary
-
#warn(msg) ⇒ nil
Writes warning message
msgto $stderr.
Class Method Details
.[](category) ⇒ Boolean
Returns the flag to show the warning messages for category. Supported categories are:
:deprecated-
deprecation warnings
-
assignment of non-nil value to
$,and$; -
keyword arguments
-
proc/lambda without block
etc.
:experimental-
experimental features
-
Pattern matching
# File 'error.c', line 188
static VALUE
rb_warning_s_aref(VALUE mod, VALUE category)
{
rb_warning_category_t cat = rb_warning_category_from_name(category);
if (rb_warning_category_enabled_p(cat))
return Qtrue;
return Qfalse;
}
.[]=(category, flag) ⇒ flag
Sets the warning flags for category. See .[] for the categories.
# File 'error.c', line 205
static VALUE
rb_warning_s_aset(VALUE mod, VALUE category, VALUE flag)
{
unsigned int mask = rb_warning_category_mask(category);
unsigned int disabled = warning_disabled_categories;
if (!RTEST(flag))
disabled |= mask;
else
disabled &= ~mask;
warning_disabled_categories = disabled;
return flag;
}
Instance Method Details
#warn(msg) ⇒ nil
Writes warning message msg to $stderr. This method is called by Ruby for all emitted warnings.
# File 'error.c', line 226
static VALUE
rb_warning_s_warn(VALUE mod, VALUE str)
{
Check_Type(str, T_STRING);
rb_must_asciicompat(str);
rb_write_error_str(str);
return Qnil;
}