如何在ruby中进行命名捕获

Question

我想命名我从扫描中得到的字符串的捕获.怎么做？

"555-333-7777".scan(/(\d{3})-(\d{3})-(\d{4})/).flatten #=> ["555", "333", "7777"]

是否有可能将其变成这样

{:area => "555", :city => "333", :local => "7777" }

要么

[["555","area"], [...]]

我试过了

"555-333-7777".scan(/((?<area>)\d{3})-(\d{3})-(\d{4})/).flatten

但它回来了

[]

Answer 1

您应该使用match命名捕获,而不是scan

m = "555-333-7777".match(/(?<area>\d{3})-(?<city>\d{3})-(?<number>\d{4})/)
m # => #<MatchData "555-333-7777" area:"555" city:"333" number:"7777">
m[:area] # => "555"
m[:city] # => "333"

如果你想要一个实际的哈希,你可以使用这样的东西:

m.names.zip(m.captures).to_h # => {"area"=>"555", "city"=>"333", "number"=>"7777"}

或者这个(红宝石2.4或更高版本)

m.named_captures # => {"area"=>"555", "city"=>"333", "number"=>"7777"}

Answer 2

像这样的东西？

"555-333-7777" =~ /^(?<area>\d+)\-(?<city>\d+)\-(?<local>\d+)$/
Hash[$~.names.collect{|x| [x.to_sym, $~[x]]}]
 => {:area=>"555", :city=>"333", :local=>"7777"}

奖金版本:

Hash[[:area, :city, :local].zip("555-333-7777".split("-"))]
=> {:area=>"555", :city=>"333", :local=>"7777"}