define keys on RegexMatch (JuliaLang#37299)

NEWS.md

@@ -46,6 +46,7 @@ Standard library changes
 * `escape_string` can now receive a collection of characters in the keyword
  `keep` that are to be kept as they are. ([#38597]).
 * `getindex` can now be used on `NamedTuple`s with multiple values ([#38878])
+* `keys(::RegexMatch)` is now defined to return the capture's keys, by name if named, or by index if not ([#37299]).
 
 #### Package Manager
 

base/regex.jl

@@ -149,16 +149,21 @@ struct RegexMatch <: AbstractMatch
  regex::Regex
 end
 
+function keys(m::RegexMatch)
+ idx_to_capture_name = PCRE.capture_names(m.regex.regex)
+ return map(eachindex(m.captures)) do i
+ # If the capture group is named, return it's name, else return it's index
+ get(idx_to_capture_name, i, i)
+ end
+end
+
 function show(io::IO, m::RegexMatch)
  print(io, "RegexMatch(")
  show(io, m.match)
- idx_to_capture_name = PCRE.capture_names(m.regex.regex)
- if !isempty(m.captures)
+ capture_keys = keys(m)
+ if !isempty(capture_keys)
  print(io, ", ")
- for i = 1:length(m.captures)
- # If the capture group is named, show the name.
- # Otherwise show its index.
- capture_name = get(idx_to_capture_name, i, i)
+ for (i, capture_name) in enumerate(capture_keys)
  print(io, capture_name, "=")
  show(io, m.captures[i])
  if i < length(m.captures)

test/regex.jl

@@ -98,6 +98,7 @@
  @test !haskey(m, "foo")
  @test (m[:a], m[2], m["b"]) == ("x", "y", "z")
  @test sprint(show, m) == "RegexMatch(\"xyz\", a=\"x\", 2=\"y\", b=\"z\")"
+ @test keys(m) == ["a", 2, "b"]
  end
 
  # Backcapture reference in substitution string