Ruby正则表达式匹配数组中的字符串？

Question

我对Ruby的正则表达式有点新鲜,(或者我认为一般都是正则表达式),但我想知道是否有一种实用的方法来匹配使用数组的字符串？

让我解释一下,说我在这种情况下有一份成分清单:

1 1/3 cups all-purpose flour
2 teaspoons ground cinnamon
8 ounces shredded mozzarella cheese

最终我需要将成分分成各自的"数量和量度"和"成分名称",所以就像在这种情况下一样2 teaspoons ground cinnamon,将分成" 8 ounces,和shredded mozzarella cheese.

所以,不要像(cup\w*|teaspoon\w*ounce\w* ....... )我这样有很长的正则表达式,如何使用数组来保存正则表达式之外的那些值？

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更新

我这样做了(感谢cwninja):

  # I think the all units should be just singular, then 
  # use ruby function to pluralize them.

units = [
  'tablespoon',
  'teaspoon',
  'cup',
  'can',
  'quart',
  'gallon',
  'pinch',
  'pound',
  'pint',
  'fluid ounce',
  'ounce'
  # ... shortened for brevity
]

joined_units = (units.collect{|u| u.pluralize} + units).join('|')

# There are actually many ingredients, so this is actually an iterator
# but for example sake we are going to just show one.
ingredient = "1 (10 ounce) can diced tomatoes and green chilies, undrained"

ingredient.split(/([\d\/\.\s]+(\([^)]+\))?)\s(#{joined_units})?\s?(.*)/i)

这让我接近我想要的东西,所以我认为这是我想要的方向.

puts "measurement: #{arr[1]}"
puts "unit: #{arr[-2] if arr.size > 3}"
puts "title: #{arr[-1].strip}"

Answer 1

就个人而言,我只是以编程方式构建正则表达式,你可以这样做:

ingredients = [...]
recipe = Regexp(ingredients.join("|"), true) # Case-insensitive

或使用union方法:

recipe = Regexp.union(ingredients)
recipe = /#{regex}/i

...然后使用正则recipe表达式.

只要你保存它并且不再继续它,它应该是相当有效的.