From dd0729091da76870a7661032c77a689cd3283de1 Mon Sep 17 00:00:00 2001
From: sloane <1699281+sloanelybutsurely@users.noreply.github.com>
Date: Fri, 1 Dec 2023 11:23:43 -0500
Subject: [PATCH] use metaprogramming to reduce loc

---
 2023/elixir/lib/2023/1.ex | 93 ++++++++++++++++-----------------------
 1 file changed, 37 insertions(+), 56 deletions(-)

diff --git a/2023/elixir/lib/2023/1.ex b/2023/elixir/lib/2023/1.ex
index f00ca9c..59a1f86 100644
--- a/2023/elixir/lib/2023/1.ex
+++ b/2023/elixir/lib/2023/1.ex
@@ -6,13 +6,13 @@ aoc 2023, 1 do
 
     firsts =
       lines
-      |> Stream.map(&to_digits/1)
+      |> Stream.map(&simple_to_digits/1)
       |> Stream.map(&List.first/1)
 
     lasts =
       lines
       |> Stream.map(&String.reverse/1)
-      |> Stream.map(&to_digits/1)
+      |> Stream.map(&simple_to_digits/1)
       |> Stream.map(&List.first/1)
 
     Stream.zip_with(firsts, lasts, &digits_to_number/2)
@@ -24,13 +24,13 @@ aoc 2023, 1 do
 
     firsts =
       lines
-      |> Stream.map(&to_digits_2/1)
+      |> Stream.map(&to_digits/1)
       |> Stream.map(&List.first/1)
 
     lasts =
       lines
       |> Stream.map(&String.reverse/1)
-      |> Stream.map(&to_digits_3/1)
+      |> Stream.map(&to_digits_reversed/1)
       |> Stream.map(&List.first/1)
 
     Stream.zip_with(firsts, lasts, &digits_to_number/2)
@@ -39,61 +39,42 @@ aoc 2023, 1 do
 
   def digits_to_number(f, l), do: String.to_integer("#{f}#{l}")
 
+  numbers = [
+    {"1", "one", 1},
+    {"2", "two", 2},
+    {"3", "three", 3},
+    {"4", "four", 4},
+    {"5", "five", 5},
+    {"6", "six", 6},
+    {"7", "seven", 7},
+    {"8", "eight", 8},
+    {"9", "nine", 9}
+  ]
+
+  def simple_to_digits(""), do: []
+
+  for {n, _, v} <- numbers do
+    def simple_to_digits(unquote(n) <> rest), do: [unquote(v) | simple_to_digits(rest)]
+  end
+
+  def simple_to_digits(<<_::binary-size(1), rest::binary>>), do: simple_to_digits(rest)
+
   def to_digits(""), do: []
-  def to_digits("1" <> rest), do: [1 | to_digits(rest)]
-  def to_digits("2" <> rest), do: [2 | to_digits(rest)]
-  def to_digits("3" <> rest), do: [3 | to_digits(rest)]
-  def to_digits("4" <> rest), do: [4 | to_digits(rest)]
-  def to_digits("5" <> rest), do: [5 | to_digits(rest)]
-  def to_digits("6" <> rest), do: [6 | to_digits(rest)]
-  def to_digits("7" <> rest), do: [7 | to_digits(rest)]
-  def to_digits("8" <> rest), do: [8 | to_digits(rest)]
-  def to_digits("9" <> rest), do: [9 | to_digits(rest)]
+
+  for {n, w, v} <- numbers do
+    def to_digits(unquote(n) <> rest), do: [unquote(v) | to_digits(rest)]
+    def to_digits(unquote(w) <> rest), do: [unquote(v) | to_digits(rest)]
+  end
+
   def to_digits(<<_::binary-size(1), rest::binary>>), do: to_digits(rest)
 
-  def to_digits_2(""), do: []
-  def to_digits_2("1" <> rest), do: [1 | to_digits_2(rest)]
-  def to_digits_2("one" <> rest), do: [1 | to_digits_2(rest)]
-  def to_digits_2("2" <> rest), do: [2 | to_digits_2(rest)]
-  def to_digits_2("two" <> rest), do: [2 | to_digits_2(rest)]
-  def to_digits_2("3" <> rest), do: [3 | to_digits_2(rest)]
-  def to_digits_2("three" <> rest), do: [3 | to_digits_2(rest)]
-  def to_digits_2("4" <> rest), do: [4 | to_digits_2(rest)]
-  def to_digits_2("four" <> rest), do: [4 | to_digits_2(rest)]
-  def to_digits_2("5" <> rest), do: [5 | to_digits_2(rest)]
-  def to_digits_2("five" <> rest), do: [5 | to_digits_2(rest)]
-  def to_digits_2("6" <> rest), do: [6 | to_digits_2(rest)]
-  def to_digits_2("six" <> rest), do: [6 | to_digits_2(rest)]
-  def to_digits_2("7" <> rest), do: [7 | to_digits_2(rest)]
-  def to_digits_2("seven" <> rest), do: [7 | to_digits_2(rest)]
-  def to_digits_2("8" <> rest), do: [8 | to_digits_2(rest)]
-  def to_digits_2("eight" <> rest), do: [8 | to_digits_2(rest)]
-  def to_digits_2("9" <> rest), do: [9 | to_digits_2(rest)]
-  def to_digits_2("nine" <> rest), do: [9 | to_digits_2(rest)]
+  def to_digits_reversed(""), do: []
 
-  def to_digits_2(<<_::binary-size(1), rest::binary>>),
-    do: to_digits_2(rest)
+  for {n, w, v} <- numbers do
+    wr = String.reverse(w)
+    def to_digits_reversed(unquote(n) <> rest), do: [unquote(v) | to_digits_reversed(rest)]
+    def to_digits_reversed(unquote(wr) <> rest), do: [unquote(v) | to_digits_reversed(rest)]
+  end
 
-  def to_digits_3(""), do: []
-  def to_digits_3("1" <> rest), do: [1 | to_digits_3(rest)]
-  def to_digits_3("eno" <> rest), do: [1 | to_digits_3(rest)]
-  def to_digits_3("2" <> rest), do: [2 | to_digits_3(rest)]
-  def to_digits_3("owt" <> rest), do: [2 | to_digits_3(rest)]
-  def to_digits_3("3" <> rest), do: [3 | to_digits_3(rest)]
-  def to_digits_3("eerht" <> rest), do: [3 | to_digits_3(rest)]
-  def to_digits_3("4" <> rest), do: [4 | to_digits_3(rest)]
-  def to_digits_3("ruof" <> rest), do: [4 | to_digits_3(rest)]
-  def to_digits_3("5" <> rest), do: [5 | to_digits_3(rest)]
-  def to_digits_3("evif" <> rest), do: [5 | to_digits_3(rest)]
-  def to_digits_3("6" <> rest), do: [6 | to_digits_3(rest)]
-  def to_digits_3("xis" <> rest), do: [6 | to_digits_3(rest)]
-  def to_digits_3("7" <> rest), do: [7 | to_digits_3(rest)]
-  def to_digits_3("neves" <> rest), do: [7 | to_digits_3(rest)]
-  def to_digits_3("8" <> rest), do: [8 | to_digits_3(rest)]
-  def to_digits_3("thgie" <> rest), do: [8 | to_digits_3(rest)]
-  def to_digits_3("9" <> rest), do: [9 | to_digits_3(rest)]
-  def to_digits_3("enin" <> rest), do: [9 | to_digits_3(rest)]
-
-  def to_digits_3(<<_::binary-size(1), rest::binary>>),
-    do: to_digits_3(rest)
+  def to_digits_reversed(<<_::binary-size(1), rest::binary>>), do: to_digits_reversed(rest)
 end