ruby - 用大写单词替换单词

Question

如果该行的第一个单词（一个或多个）都在 CAPs 中，我想用大写单词替换这些单词（使用 ruby​​'s .capitalize）。例如“FOO BAR”到“Foo Bar”

我尝试了以下方法：

line.gsub!(/^([A-Z ]+)/, '\1'.capitalize)

和

line.gsub!(/^([A-Z ]+)/, "\\1".capitalize)

两者都不起作用。有没有办法做到这一点？

Answer 1

尝试：

line.gsub!(/^([A-Z ]+)/) { |w| w.capitalize }

在 IRB 中：

require 'active_support'
'FOO bar'.gsub(/^[A-Z]+/) { |w| w.capitalize }
 => "Foo bar" 

或OP的版本：

'FOO bar'.gsub!(/^([A-Z ]+)/) { |w| w.capitalize }
 => "Foo bar" 

对于前两个词，这是快速而肮脏的：

'FOO BAR'.gsub!(/^([A-Z ]+ [A-Z]+)/) { |w| w.capitalize }
 => "Foo bar" 

您可以使用以下方法变得更漂亮：

'FOO BAR'.gsub!(/^((?<word>[A-Z]+) \g<word>)/) { |w| w.capitalize }
 => "Foo bar" 

当然，在固定字符串上使用 的!版本gsub不会做任何有用的事情。

---

OP 添加了额外的约束：

require 'active_support'

line = 'AFOO BFOO CFOO DFOO e f g'
words = line[/^(?:[A-Z]+ )+/].split.map{ |w| w.capitalize } # => ["Afoo", "Bfoo", "Cfoo", "Dfoo"] 
[words,line.split[words.size..-1]].join(' ')                # => "Afoo Bfoo Cfoo Dfoo e f g" 

Answer 2

You want to capitalize all words in line, correct? Try String#scan instead:

line.scan(/\w+|\W+/).map(&:capitalize).join

Answer 3

I'm no Ruby programmer, but I can see that you're calling capitalize on the string \1, which of course is just \1 again. You will want to look for something similar to PHP's preg_replace_callback that will allow you to run regex matches through a function - in this case, capitalize.