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41e24c2f3e
(https://github.com/ruby/strscan/pull/126)
Split off from https://github.com/ruby/ruby/pull/12322
9bee37e0f5
124 lines
3.2 KiB
Markdown
124 lines
3.2 KiB
Markdown
## Helper Methods
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These helper methods display values returned by scanner's methods.
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### `put_situation(scanner)`
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Display scanner's situation:
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- Byte position (`#pos`).
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- Character position (`#charpos`)
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- Target string (`#rest`) and size (`#rest_size`).
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```rb
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scanner = StringScanner.new('foobarbaz')
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scanner.scan(/foo/)
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put_situation(scanner)
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# Situation:
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# pos: 3
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# charpos: 3
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# rest: "barbaz"
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# rest_size: 6
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```
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### `put_match_values(scanner)`
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Display the scanner's match values:
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```rb
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scanner = StringScanner.new('Fri Dec 12 1975 14:39')
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pattern = /(?<wday>\w+) (?<month>\w+) (?<day>\d+) /
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scanner.match?(pattern)
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put_match_values(scanner)
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# Basic match values:
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# matched?: true
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# matched_size: 11
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# pre_match: ""
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# matched : "Fri Dec 12 "
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# post_match: "1975 14:39"
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# Captured match values:
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# size: 4
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# captures: ["Fri", "Dec", "12"]
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# named_captures: {"wday"=>"Fri", "month"=>"Dec", "day"=>"12"}
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# values_at: ["Fri Dec 12 ", "Fri", "Dec", "12", nil]
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# []:
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# [0]: "Fri Dec 12 "
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# [1]: "Fri"
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# [2]: "Dec"
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# [3]: "12"
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# [4]: nil
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```
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### `match_values_cleared?(scanner)`
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Returns whether the scanner's match values are all properly cleared:
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```rb
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scanner = StringScanner.new('foobarbaz')
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match_values_cleared?(scanner) # => true
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put_match_values(scanner)
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# Basic match values:
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# matched?: false
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# matched_size: nil
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# pre_match: nil
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# matched : nil
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# post_match: nil
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# Captured match values:
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# size: nil
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# captures: nil
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# named_captures: {}
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# values_at: nil
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# [0]: nil
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scanner.scan(/foo/)
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match_values_cleared?(scanner) # => false
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```
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## The Code
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```rb
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def put_situation(scanner)
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puts '# Situation:'
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puts "# pos: #{scanner.pos}"
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puts "# charpos: #{scanner.charpos}"
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puts "# rest: #{scanner.rest.inspect}"
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puts "# rest_size: #{scanner.rest_size}"
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end
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def put_match_values(scanner)
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puts '# Basic match values:'
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puts "# matched?: #{scanner.matched?}"
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value = scanner.matched_size || 'nil'
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puts "# matched_size: #{value}"
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puts "# pre_match: #{scanner.pre_match.inspect}"
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puts "# matched : #{scanner.matched.inspect}"
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puts "# post_match: #{scanner.post_match.inspect}"
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puts '# Captured match values:'
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puts "# size: #{scanner.size}"
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puts "# captures: #{scanner.captures}"
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puts "# named_captures: #{scanner.named_captures}"
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if scanner.size.nil?
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puts "# values_at: #{scanner.values_at(0)}"
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puts "# [0]: #{scanner[0]}"
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else
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puts "# values_at: #{scanner.values_at(*(0..scanner.size))}"
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puts "# []:"
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scanner.size.times do |i|
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puts "# [#{i}]: #{scanner[i].inspect}"
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end
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end
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end
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def match_values_cleared?(scanner)
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scanner.matched? == false &&
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scanner.matched_size.nil? &&
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scanner.matched.nil? &&
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scanner.pre_match.nil? &&
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scanner.post_match.nil? &&
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scanner.size.nil? &&
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scanner[0].nil? &&
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scanner.captures.nil? &&
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scanner.values_at(0..1).nil? &&
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scanner.named_captures == {}
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end
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```
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