Switch from Regex-based parsing to NimbleParsec grammar-based parsing

.github/workflows/build.yml

@@ -1,90 +1,24 @@
 ---
-name: edtf
+name: test
 on: [push]
 jobs:
   test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        elixir:
-          - 1.15-25
-          - 1.15-26
-          - 1.16-25
-          - 1.16-26
-          - 1.17-25
-          - 1.17-26
-          - 1.17-27
     env:
       MIX_ENV: test
     steps:
-      - name: Set Elixir and OTP versions
-        id: elixir-otp
-        run: |
-          echo "elixir=$(sed 's/-.*$//' <<< $version)" >> $GITHUB_OUTPUT
-          echo "otp=$(sed 's/^.*-//' <<< $version)" >> $GITHUB_OUTPUT
-        env:
-          version: ${{ matrix.elixir }}
       - uses: actions/checkout@v2
       - uses: erlef/setup-beam@v1
         with:
-          otp-version: ${{ steps.elixir-otp.outputs.otp }}
-          elixir-version: ${{ steps.elixir-otp.outputs.elixir }}
-      - name: Cache Elixir dependencies
-        uses: actions/cache@v2
-        with:
-          path: |
-            deps
-            _build
-          key: ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-${{ hashFiles('mix.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-${{ hashFiles('mix.lock') }}
-            ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-
+          otp-version: 27
+          elixir-version: 1.17
       - name: Install Dependencies
         run: mix do deps.get, deps.compile
       - name: Static Analysis
         run: mix credo --strict
         env:
           MIX_ENV: test
       - name: Run Tests
-        run: mix test --trace
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-  build:
-    runs-on: ubuntu-latest
-    needs: test
-    steps:
-      - name: Pass all checks
-        run: echo "Tests passed"
-  coverage:
-    runs-on: ubuntu-latest
-    env:
-      MIX_ENV: test
-    steps:
-      - name: Set Elixir and OTP versions
-        id: elixir-otp
-        run: |
-          echo "elixir=$(sed 's/-.*$//' <<< $version)" >> $GITHUB_OUTPUT
-          echo "otp=$(sed 's/^.*-//' <<< $version)" >> $GITHUB_OUTPUT
-        env:
-          version: "1.17-27"
-      - uses: actions/checkout@v2
-      - uses: erlef/setup-beam@v1
-        with:
-          otp-version: ${{ steps.elixir-otp.outputs.otp }}
-          elixir-version: ${{ steps.elixir-otp.outputs.elixir }}
-      - name: Cache Elixir dependencies
-        uses: actions/cache@v2
-        with:
-          path: |
-            deps
-            _build
-          key: ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-${{ hashFiles('mix.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-${{ hashFiles('mix.lock') }}
-            ${{ runner.os }}-deps-${{ steps.elixir-otp.outputs.elixir }}-${{ steps.elixir-otp.outputs.otp }}-
-      - name: Install Dependencies
-        run: mix do deps.get, deps.compile
-      - name: Run Tests & Coverage Analysis
         run: mix coveralls.github --trace
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -33,4 +33,3 @@ See `EDTF.parse/1`, `EDTF.validate/1`, and `EDTF.humanize/1`.
 
 - Some human-readable dates containing Level 2 qualifications and years with significant digits, 
   may produce less specific results than desired.
-- Level 2 years without the leading `Y` character (e.g., `2024S03`) are not supported at this time.

lib/edtf.ex

@@ -17,14 +17,21 @@ defmodule EDTF do
     {:error, :invalid_format}
     ```
   """
-  def parse(edtf, include \\ [Interval, Aggregate, Date]) do
-    case Enum.find(include, & &1.match?(edtf)) do
-      nil -> error()
-      mod -> mod.parse(edtf)
+  def parse(edtf) do
+    case EDTF.Parser.parse(edtf) do
+      {:ok, [result], _, _, _, _} -> {:ok, assemble(result) |> Level.add_level()}
+      {:error, _, _, _, _, _} -> {:error, :invalid_format}
     end
-    |> Level.add_level()
   end
 
+  defp assemble({:date, _} = result), do: Date.assemble(result)
+  defp assemble({:year, _} = result), do: Date.assemble(result)
+  defp assemble({:decade, _} = result), do: Date.assemble(result)
+  defp assemble({:century, _} = result), do: Date.assemble(result)
+  defp assemble({:interval, _} = result), do: Interval.assemble(result)
+  defp assemble({:set, _} = result), do: Aggregate.assemble(result)
+  defp assemble({:list, _} = result), do: Aggregate.assemble(result)
+
   @doc """
   Validate an EDTF date string
 
@@ -62,28 +69,4 @@ defmodule EDTF do
       other -> other
     end
   end
-
-  @doc """
-  Generate an error response
-  """
-  def error(error \\ :invalid_format), do: {:error, error}
-
-  @doc """
-  Identify the open-ended continuation markers on an EDTF date string
-  """
-  def open_ended(edtf) do
-    case Regex.named_captures(~r/^(?<earlier>\.\.)?(?<edtf>.+?)(?<later>\.\.)?$/, edtf) do
-      %{"earlier" => "..", "edtf" => result, "later" => ".."} ->
-        {result, [{:earlier, true}, {:later, true}]}
-
-      %{"earlier" => "..", "edtf" => result} ->
-        {result, [{:earlier, true}, {:later, false}]}
-
-      %{"edtf" => result, "later" => ".."} ->
-        {result, [{:earlier, false}, {:later, true}]}
-
-      %{"edtf" => result} ->
-        {result, [{:earlier, false}, {:later, false}]}
-    end
-  end
 end

lib/edtf/aggregate.ex

@@ -3,10 +3,6 @@ defmodule EDTF.Aggregate do
   Parser for EDTF Lists and Sets
   """
 
-  @matchers list: ~r/^\{(.+)\}$/, set: ~r/^\[(.+)\]$/
-
-  @valid [EDTF.Date, EDTF.Range]
-
   defstruct type: nil, values: [], level: 2, earlier: false, later: false
 
   @type t :: %__MODULE__{
@@ -17,38 +13,21 @@ defmodule EDTF.Aggregate do
           later: boolean()
         }
 
-  def match?(edtf), do: Enum.any?(@matchers, fn {_, re} -> Regex.match?(re, edtf) end)
-
-  def parse(edtf) do
-    case Enum.find(@matchers, fn {_, re} -> Regex.match?(re, edtf) end) do
-      nil ->
-        EDTF.error()
-
-      {type, re} ->
-        [_, dates] = Regex.run(re, edtf)
-        {dates, attributes} = EDTF.open_ended(dates)
-
-        Regex.split(~r/\s*,\s*/, dates)
-        |> Enum.reduce_while([], &reducer/2)
-        |> finalize(type, attributes)
-    end
-  end
-
-  defp reducer(date, acc) do
-    case EDTF.parse(date, @valid) do
-      {:ok, parsed} -> {:cont, [parsed | acc]}
-      {:error, _error} -> {:halt, :error}
-    end
-  end
-
-  defp finalize(:error, _, _), do: EDTF.error()
-
-  defp finalize(values, type, attributes),
-    do: %__MODULE__{
-      type: type,
-      values: Enum.reverse(values),
-      earlier: attributes[:earlier],
-      later: attributes[:later],
-      level: 2
+  def assemble({:list, value}), do: %__MODULE__{assemble(value) | type: :list}
+  def assemble({:set, value}), do: %__MODULE__{assemble(value) | type: :set}
+
+  def assemble(value) do
+    dates =
+      Keyword.get(value, :dates, [])
+      |> Enum.map(fn
+        [{:interval, _}] = v -> EDTF.Interval.assemble(v)
+        v -> EDTF.Date.assemble({:date, v})
+      end)
+
+    %__MODULE__{
+      values: dates,
+      earlier: Keyword.get(value, :earlier, false),
+      later: Keyword.get(value, :later, false)
     }
+  end
 end