Extract problem formatter to separate module

lib/dantzig.ex

@@ -3,6 +3,7 @@ defmodule Dantzig do
   Documentation for `Dantzig`.
   """
 
+  alias Dantzig.Format.CPLEX
   alias Dantzig.HiGHS
   alias Dantzig.Problem
 
@@ -16,7 +17,7 @@ defmodule Dantzig do
   end
 
   def dump_problem_to_file(%Problem{} = problem, path) do
-    iodata = HiGHS.to_lp_iodata(problem)
+    iodata = CPLEX.to_iodata(problem)
     File.write!(path, iodata)
   end
 end

lib/dantzig/format/cplex.ex

@@ -0,0 +1,93 @@
+defmodule Dantzig.Format.CPLEX do
+  alias Dantzig.Constraint
+  alias Dantzig.Polynomial
+  alias Dantzig.Problem
+  alias Dantzig.ProblemVariable
+
+  def to_iodata(%Problem{} = problem) do
+    constraints = Enum.sort(problem.constraints)
+
+    constraints_iodata =
+      Enum.map(constraints, fn {_id, constraint} ->
+        constraint_to_iodata(constraint)
+      end)
+
+    bounds = all_variable_bounds(Map.values(problem.variables))
+    integers = variables_by_type(problem.variables, :integer)
+    binaries = variables_by_type(problem.variables, :binary)
+
+    [
+      direction_to_iodata(problem.direction),
+      "\n  ",
+      Polynomial.to_lp_iodata_objective(problem.objective),
+      "\n",
+      "Subject To\n",
+      constraints_iodata,
+      "Bounds\n",
+      bounds,
+      "General\n",
+      list_variables(integers),
+      "Binary\n",
+      list_variables(binaries),
+      "End\n"
+    ]
+  end
+
+  defp constraint_to_iodata(constraint = %Constraint{}) do
+    [
+      "  ",
+      constraint.name,
+      ": ",
+      Polynomial.to_lp_constraint(constraint.left_hand_side),
+      " ",
+      operator_to_iodata(constraint.operator),
+      " ",
+      to_string(constraint.right_hand_side),
+      "\n"
+    ]
+  end
+
+  defp operator_to_iodata(operator) do
+    case operator do
+      :== -> "="
+      other -> to_string(other)
+    end
+  end
+
+  defp direction_to_iodata(:maximize), do: "Maximize"
+  defp direction_to_iodata(:minimize), do: "Minimize"
+
+
+  # Bounds have higher priority than variable type. So we need to exclude the :binary type here.
+  defp variable_bounds(%ProblemVariable{type: :binary}), do: ""
+
+  defp variable_bounds(%ProblemVariable{} = v) do
+    case {v.min, v.max} do
+      {nil, nil} ->
+        "  #{v.name} free\n"
+
+      {nil, max} ->
+        "  #{v.name} <= #{max}\n"
+
+      {min, nil} ->
+        "  #{min} <= #{v.name}\n"
+
+      {min, max} ->
+        "  #{min} <= #{v.name}\n  #{v.name} <= #{max}\n"
+    end
+  end
+
+  defp all_variable_bounds(variables) do
+    Enum.map(variables, &variable_bounds/1)
+  end
+
+  defp variables_by_type(variables, type) do
+    for {name, %{type: ^type}} <- variables, do: name
+  end
+
+  defp list_variables([]), do: []
+
+  defp list_variables(variables) do
+    for name <- variables, do: "  #{name}\n"
+  end
+end

lib/dantzig/highs.ex

@@ -1,17 +1,19 @@
 defmodule Dantzig.HiGHS do
-  @moduledoc false
+  @moduledoc """
+  Find solutions using [HiGHS solver][highs].
+
+  [highs]: https://highs.dev
+  """
 
-  require Dantzig.Problem, as: Problem
   alias Dantzig.Config
-  alias Dantzig.Constraint
-  alias Dantzig.ProblemVariable
+  alias Dantzig.Format.CPLEX
+  alias Dantzig.Problem
   alias Dantzig.Solution
-  alias Dantzig.Polynomial
 
   @max_random_prefix 2 ** 32
 
   def solve(%Problem{} = problem) do
-    iodata = to_lp_iodata(problem)
+    iodata = CPLEX.to_iodata(problem)
 
     command = Config.get_highs_binary_path()
 
@@ -76,90 +78,4 @@ defmodule Dantzig.HiGHS do
       File.rm_rf(dirpath)
     end
   end
-
-  defp constraint_to_iodata(constraint = %Constraint{}) do
-    [
-      "  ",
-      constraint.name,
-      ": ",
-      Polynomial.to_lp_constraint(constraint.left_hand_side),
-      " ",
-      operator_to_iodata(constraint.operator),
-      " ",
-      to_string(constraint.right_hand_side),
-      "\n"
-    ]
-  end
-
-  defp operator_to_iodata(operator) do
-    case operator do
-      :== -> "="
-      other -> to_string(other)
-    end
-  end
-
-  defp direction_to_iodata(:maximize), do: "Maximize"
-  defp direction_to_iodata(:minimize), do: "Minimize"
-
-  def to_lp_iodata(%Problem{} = problem) do
-    constraints = Enum.sort(problem.constraints)
-
-    constraints_iodata =
-      Enum.map(constraints, fn {_id, constraint} ->
-        constraint_to_iodata(constraint)
-      end)
-
-    bounds = all_variable_bounds(Map.values(problem.variables))
-    integers = variables_by_type(problem.variables, :integer)
-    binaries = variables_by_type(problem.variables, :binary)
-
-    [
-      direction_to_iodata(problem.direction),
-      "\n  ",
-      Polynomial.to_lp_iodata_objective(problem.objective),
-      "\n",
-      "Subject To\n",
-      constraints_iodata,
-      "Bounds\n",
-      bounds,
-      "General\n",
-      list_variables(integers),
-      "Binary\n",
-      list_variables(binaries),
-      "End\n"
-    ]
-  end
-
-  # Bounds have higher priority than variable type. So we need to exclude the :binary type here.
-  defp variable_bounds(%ProblemVariable{type: :binary}), do: ""
-
-  defp variable_bounds(%ProblemVariable{} = v) do
-    case {v.min, v.max} do
-      {nil, nil} ->
-        "  #{v.name} free\n"
-
-      {nil, max} ->
-        "  #{v.name} <= #{max}\n"
-
-      {min, nil} ->
-        "  #{min} <= #{v.name}\n"
-
-      {min, max} ->
-        "  #{min} <= #{v.name}\n  #{v.name} <= #{max}\n"
-    end
-  end
-
-  defp all_variable_bounds(variables) do
-    Enum.map(variables, &variable_bounds/1)
-  end
-
-  defp variables_by_type(variables, type) do
-    for {name, %{type: ^type}} <- variables, do: name
-  end
-
-  defp list_variables([]), do: []
-
-  defp list_variables(variables) do
-    for name <- variables, do: "  #{name}\n"
-  end
 end

lib/dantzig/highs_downloader.ex

@@ -2,8 +2,6 @@ defmodule Dantzig.HiGHSDownloader do
   alias Dantzig.Config
   require Logger
 
-  @external_resource Dantzig.Config.get_highs_binary_path()
-
   def maybe_download_for_target() do
     downloaded_version = Config.read_downloaded_version()
     highs_version = Config.get_highs_version()
@@ -52,7 +50,7 @@ defmodule Dantzig.HiGHSDownloader do
     unpacked =
       :erl_tar.extract({:binary, tar_archive}, [
         :compressed,
-        files: [~c'bin/highs'],
+        files: [~c"bin/highs"],
         cwd: to_charlist(tmp_dir)
       ])
 

lib/dantzig/problem.ex

@@ -21,10 +21,10 @@ defmodule Dantzig.Problem do
             direction: nil,
             variables: %{},
             constraints: %{},
-            contraints_metadata: %{}
+            constraints_metadata: %{}
 
   @spec solve_for_all_variables(t()) :: %{
-          ProblemVariable.variable_namme() => SolvedConstraint.t()
+          ProblemVariable.variable_name() => SolvedConstraint.t()
         }
   def solve_for_all_variables(%__MODULE__{} = problem) do
     # There are two ways of solving for all variables:

mix.exs

@@ -17,7 +17,7 @@ defmodule Dantzig.MixProject do
       elixirc_paths: elixirc_paths(Mix.env()),
       package: package(),
       name: "Danztig",
-      description: "Linear progamming solver for elixir",
+      description: "Linear programming solver for elixir",
       source_url: "https://github.com/tmbb/dantzig"
     ]
   end
@@ -45,9 +45,10 @@ defmodule Dantzig.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      {:nimble_parsec, "~> 1.4"},
+      {:nimble_parsec, "~> 1.4", runtime: false},
       {:ex_doc, "~> 0.36", only: :dev, runtime: false},
-      {:stream_data, "~> 1.1", only: [:test, :dev]}
+      {:stream_data, "~> 1.1", only: [:test, :dev]},
+      {:mneme, "~> 0.10.2", only: :test}
     ]
   end
 

mix.lock

@@ -1,9 +1,28 @@
 %{
   "earmark_parser": {:hex, :earmark_parser, "1.4.43", "34b2f401fe473080e39ff2b90feb8ddfeef7639f8ee0bbf71bb41911831d77c5", [:mix], [], "hexpm", "970a3cd19503f5e8e527a190662be2cee5d98eed1ff72ed9b3d1a3d466692de8"},
   "ex_doc": {:hex, :ex_doc, "0.37.1", "65ca30d242082b95aa852b3b73c9d9914279fff56db5dc7b3859be5504417980", [:mix], [{:earmark_parser, "~> 1.4.42", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "6774f75477733ea88ce861476db031f9399c110640752ca2b400dbbb50491224"},
+  "file_system": {:hex, :file_system, "1.1.1", "31864f4685b0148f25bd3fbef2b1228457c0c89024ad67f7a81a3ffbc0bbad3a", [:mix], [], "hexpm", "7a15ff97dfe526aeefb090a7a9d3d03aa907e100e262a0f8f7746b78f8f87a5d"},
+  "finch": {:hex, :finch, "0.20.0", "5330aefb6b010f424dcbbc4615d914e9e3deae40095e73ab0c1bb0968933cadf", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.6.2 or ~> 1.7", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.1", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "2658131a74d051aabfcba936093c903b8e89da9a1b63e430bee62045fa9b2ee2"},
+  "glob_ex": {:hex, :glob_ex, "0.1.11", "cb50d3f1ef53f6ca04d6252c7fde09fd7a1cf63387714fe96f340a1349e62c93", [:mix], [], "hexpm", "342729363056e3145e61766b416769984c329e4378f1d558b63e341020525de4"},
+  "hpax": {:hex, :hpax, "1.0.3", "ed67ef51ad4df91e75cc6a1494f851850c0bd98ebc0be6e81b026e765ee535aa", [:mix], [], "hexpm", "8eab6e1cfa8d5918c2ce4ba43588e894af35dbd8e91e6e55c817bca5847df34a"},
+  "igniter": {:hex, :igniter, "0.5.52", "18777a36918e3bb91c70f07b69f6a6589d8fa5547a7d210b228d410a2453923f", [:mix], [{:glob_ex, "~> 0.1.7", [hex: :glob_ex, repo: "hexpm", optional: false]}, {:inflex, "~> 2.0", [hex: :inflex, repo: "hexpm", optional: false]}, {:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}, {:owl, "~> 0.11", [hex: :owl, repo: "hexpm", optional: false]}, {:phx_new, "~> 1.7", [hex: :phx_new, repo: "hexpm", optional: true]}, {:req, "~> 0.5", [hex: :req, repo: "hexpm", optional: false]}, {:rewrite, ">= 1.1.1 and < 2.0.0-0", [hex: :rewrite, repo: "hexpm", optional: false]}, {:sourceror, "~> 1.4", [hex: :sourceror, repo: "hexpm", optional: false]}, {:spitfire, ">= 0.1.3 and < 1.0.0-0", [hex: :spitfire, repo: "hexpm", optional: false]}], "hexpm", "8d75f0f2307e21b53ad96bd746f1806da91859ec0d4a68b203b763da4d5ae567"},
+  "inflex": {:hex, :inflex, "2.1.0", "a365cf0821a9dacb65067abd95008ca1b0bb7dcdd85ae59965deef2aa062924c", [:mix], [], "hexpm", "14c17d05db4ee9b6d319b0bff1bdf22aa389a25398d1952c7a0b5f3d93162dd8"},
+  "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
   "makeup_erlang": {:hex, :makeup_erlang, "1.0.2", "03e1804074b3aa64d5fad7aa64601ed0fb395337b982d9bcf04029d68d51b6a7", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "af33ff7ef368d5893e4a267933e7744e46ce3cf1f61e2dccf53a111ed3aa3727"},
+  "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
+  "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
+  "mneme": {:hex, :mneme, "0.10.2", "f263ff74e993ef9eb160e04b608a149881e601ed6f5508c9afcafb578a184b52", [:mix], [{:file_system, "~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:igniter, "~> 0.3.76 or ~> 0.4.0 or ~> 0.5.0", [hex: :igniter, repo: "hexpm", optional: false]}, {:nimble_options, "~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:owl, "~> 0.9", [hex: :owl, repo: "hexpm", optional: false]}, {:rewrite, "~> 1.0", [hex: :rewrite, repo: "hexpm", optional: false]}, {:sourceror, "~> 1.0", [hex: :sourceror, repo: "hexpm", optional: false]}, {:text_diff, "~> 0.1", [hex: :text_diff, repo: "hexpm", optional: false]}], "hexpm", "3b9493fc114c4bb0f6232e021620ffd7944819b9b9105a5b286b6dc907f7720a"},
+  "nimble_options": {:hex, :nimble_options, "1.1.1", "e3a492d54d85fc3fd7c5baf411d9d2852922f66e69476317787a7b2bb000a61b", [:mix], [], "hexpm", "821b2470ca9442c4b6984882fe9bb0389371b8ddec4d45a9504f00a66f650b44"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
+  "nimble_pool": {:hex, :nimble_pool, "1.1.0", "bf9c29fbdcba3564a8b800d1eeb5a3c58f36e1e11d7b7fb2e084a643f645f06b", [:mix], [], "hexpm", "af2e4e6b34197db81f7aad230c1118eac993acc0dae6bc83bac0126d4ae0813a"},
+  "owl": {:hex, :owl, "0.13.0", "26010e066d5992774268f3163506972ddac0a7e77bfe57fa42a250f24d6b876e", [:mix], [{:ucwidth, "~> 0.2", [hex: :ucwidth, repo: "hexpm", optional: true]}], "hexpm", "59bf9d11ce37a4db98f57cb68fbfd61593bf419ec4ed302852b6683d3d2f7475"},
+  "req": {:hex, :req, "0.5.16", "99ba6a36b014458e52a8b9a0543bfa752cb0344b2a9d756651db1281d4ba4450", [:mix], [{:brotli, "~> 0.3.1", [hex: :brotli, repo: "hexpm", optional: true]}, {:ezstd, "~> 1.0", [hex: :ezstd, repo: "hexpm", optional: true]}, {:finch, "~> 0.17", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mime, "~> 2.0.6 or ~> 2.1", [hex: :mime, repo: "hexpm", optional: false]}, {:nimble_csv, "~> 1.0", [hex: :nimble_csv, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: true]}], "hexpm", "974a7a27982b9b791df84e8f6687d21483795882a7840e8309abdbe08bb06f09"},
+  "rewrite": {:hex, :rewrite, "1.2.0", "80220eb14010e175b67c939397e1a8cdaa2c32db6e2e0a9d5e23e45c0414ce21", [:mix], [{:glob_ex, "~> 0.1", [hex: :glob_ex, repo: "hexpm", optional: false]}, {:sourceror, "~> 1.0", [hex: :sourceror, repo: "hexpm", optional: false]}, {:text_diff, "~> 0.1", [hex: :text_diff, repo: "hexpm", optional: false]}], "hexpm", "a1cd702bbb9d51613ab21091f04a386d750fc6f4516b81900df082d78b2d8c50"},
+  "sourceror": {:hex, :sourceror, "1.10.0", "38397dedbbc286966ec48c7af13e228b171332be1ad731974438c77791945ce9", [:mix], [], "hexpm", "29dbdfc92e04569c9d8e6efdc422fc1d815f4bd0055dc7c51b8800fb75c4b3f1"},
+  "spitfire": {:hex, :spitfire, "0.2.1", "29e154873f05444669c7453d3d931820822cbca5170e88f0f8faa1de74a79b47", [:mix], [], "hexpm", "6eeed75054a38341b2e1814d41bb0a250564092358de2669fdb57ff88141d91b"},
   "stream_data": {:hex, :stream_data, "1.1.3", "15fdb14c64e84437901258bb56fc7d80aaf6ceaf85b9324f359e219241353bfb", [:mix], [], "hexpm", "859eb2be72d74be26c1c4f272905667672a52e44f743839c57c7ee73a1a66420"},
+  "telemetry": {:hex, :telemetry, "1.3.0", "fedebbae410d715cf8e7062c96a1ef32ec22e764197f70cda73d82778d61e7a2", [:rebar3], [], "hexpm", "7015fc8919dbe63764f4b4b87a95b7c0996bd539e0d499be6ec9d7f3875b79e6"},
+  "text_diff": {:hex, :text_diff, "0.1.0", "1caf3175e11a53a9a139bc9339bd607c47b9e376b073d4571c031913317fecaa", [:mix], [], "hexpm", "d1ffaaecab338e49357b6daa82e435f877e0649041ace7755583a0ea3362dbd7"},
 }