Awesome

Exquisite match_specs for Elixir

Ever had to write a complex match_spec and ended up with a bunch of unintelligible code you hoped you would never have to work on ever again?

Those times are gone! Say hello to Exquisite!

What is this?

Exquisite converts a LINQ-inspired query language into match_specs at compile time so you can use them with mnesia, ets and dets.

It supports record reflection to access record fields directly in the query and allows complex data generation and compare.

It also has some helpers to select with matchspecs from tuples and list of tuples.

Examples

require Exquisite

s = Exquisite.match URI.Info,
      where:  host == "google.com",
      select: path
  
r = Exquisite.run! s, [ URI.parse("http://google.com/derp"),
                        URI.parse("http://yahoo.com/herp"),
                        URI.parse("http://bing.com/durp"),
                        URI.parse("http://google.com/herp") ]

IO.inspect r # => ["/derp", "/herp"]

require Exquisite

s = Exquisite.match { x, y, z },
      where:  z > 2 and y < 3,
      select: x

r = Exquisite.run! s, [ { 1, 2, 3 },
                        { 4, 5, 6 },
                        { 7, 8, 9 } ]

IO.inspect r # => [1]

require Exquisite

s = Exquisite.match { uri in URI.Info, x in { a, b } },
      where:  uri.path == nil,
      select: { x.b, x.a }

r = Exquisite.run! s, [ { URI.parse("http://google.com/derp"), { 1, 2 } },
                        { URI.parse("http://yahoo.com"), { 2, 3 } },
                        { URI.parse("http://bing.com/durp"), { 4, 5 } },
                        { URI.parse("http://google.com"), { 6, 7 } } ]

IO.inspect r # => [{3, 2}, {7, 6}]