[#77789] [Ruby trunk Feature#12012] Add Boolean method — prodis@...
Issue #12012 has been updated by Fernando Hamasaki de Amorim.
4 messages
2016/10/27
[ruby-core:77788] [Ruby trunk Feature#11848] New #to_b method for String, Symbol, Numeric, NilClass, TrueClass and FalseClass.
From:
prodis@...
Date:
2016-10-27 23:14:24 UTC
List:
ruby-core #77788
Issue #11848 has been updated by Fernando Hamasaki de Amorim.
Andrew Vit wrote:
> I've had to do this in a few places over the years myself:
>
> ~~~
> TRUTHY_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE', 'y', 'Y', 'yes', 'YES']
> FALSY_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE', 'n', 'N', 'no', 'NO']
> ~~~
>
> > You forgot empty string/array/hash to be false. ;-)
>
> I think the main reason for this is handling user input (from a file like CSV or other), so other types like Array/Hash are not expected there: just basic scalar values.
>
> Still, it probably only makes sense for some specific situations.
Andrew Vit, you can use **`wannabe_bool`** gem: https://github.com/prodis/wannabe_bool
----------------------------------------
Feature #11848: New #to_b method for String, Symbol, Numeric, NilClass, TrueClass and FalseClass.
https://bugs.ruby-lang.org/issues/11848#change-61093
* Author: Fernando Hamasaki de Amorim
* Status: Rejected
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
New ***to_b*** method converts **strings**, **symbols**, **numbers** and **nil** values in a **boolean** value.
***to_b*** method is available on ***String***, ***Symbol***, ***Numeric***, ***TrueClass***, ***FalseClass*** and ***NilClass*** classes.
## String
Returns ***true*** if string is one of **t**, **true**, **on**, **y**, **yes** or **1** values. Returns ***false*** otherwise.
Ignores trailing spaces and letter cases.
~~~ruby
't'.to_b # => true
'true'.to_b # => true
'on'.to_b # => true
'y'.to_b # => true
'yes'.to_b # => true
'1'.to_b # => true
''.to_b # => false
'0'.to_b # => false
'2'.to_b # => false
'-1'.to_b # => false
'f'.to_b # => false
'false'.to_b # => false
'off'.to_b # => false
'n'.to_b # => false
'no'.to_b # => false
'wherever'.to_b # => false
~~~
## Symbol
Same as ***symbol.to_s.to_b***.
~~~ruby
:'1'.to_b # => true
:t.to_b # => true
:true.to_b # => true
:on.to_b # => true
:y.to_b # => true
:yes.to_b # => true
:f.to_b # => false
:false.to_b # => false
:off.to_b # => false
:n.to_b # => false
:no.to_b # => false
:wherever.to_b # => false
~~~
## Numeric
Returns ***false*** if number is **zero**. Returns ***true*** otherwise.
### Integer
~~~ruby
0.to_b # => false
1.to_b # => true
2.to_b # => true
-1.to_b # => true
-2.to_b # => true
~~~
### Float
~~~ruby
0.0.to_b # => false
0.1.to_b # => true
1.0.to_b # => true
-0.1.to_b # => true
-1.0.to_b # => true
~~~
### BigDecimal
~~~ruby
require 'bigdecimal'
BigDecimal('0.0').to_b # => false
BigDecimal('0.1').to_b # => true
BigDecimal('1.0').to_b # => true
BigDecimal('-0.1').to_b # => true
BigDecimal('-1.0').to_b # => true
~~~
## NilClass
Returns ***false***.
~~~ruby
nil.to_b # => false
~~~
## TrueClass
Returns ***true***.
~~~ruby
true.to_b # => true
~~~
## FalseClass
Returns ***false***.
~~~ruby
false.to_b # => false
~~~
---Files--------------------------------
to_b_method.diff (9.63 KB)
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