bahaghari/lib: add pow and generateConversionTable

subprojects/bahaghari/lib/default.nix

@@ -21,6 +21,6 @@ pkgs.lib.makeExtensible
     tinted-theming = callLibs ./tinted-theming.nix;
 
     inherit (self.trivial) importYAML toYAML toBaseDigitsWithGlyphs
-      generateGlyphSet;
-    inherit (self.hex) toHexString isHexString;
+      generateGlyphSet generateConversionTable pow;
+    inherit (self.hex) toHexString isHexString hexToDec;
   })

subprojects/bahaghari/lib/trivial.nix

@@ -73,4 +73,50 @@
           glyphsList;
     in
     pkgs.lib.foldl (acc: glyph: acc // glyph) { } glyphsList';
+
+  /* Generates a conversion table for a sorted list of glyphs to its decimal
+     number. Suitable for creating your own conversion function. Accepts the
+     same argument as `generateGlyphSet`.
+
+     Type: generateConversionTable :: [ String ] -> Attrs
+
+     Example:
+       generateGlyphSet [ "0" "1" "2" "3" "4" "5" "6" "7" "8 "9" "A" "B" "C" "D" "E" "F" ]
+       => {
+         "0" = 0;
+         "1" = 1;
+         # ...
+         "E" = 14;
+         "F" = 15;
+       }
+  */
+  generateConversionTable = glyphsList:
+    let
+      glyphsList' =
+        pkgs.lib.lists.imap0
+          (i: glyph: pkgs.lib.nameValuePair glyph i)
+          glyphsList;
+    in
+    pkgs.lib.listToAttrs glyphsList';
+
+  /* Exponentiates the given base with the exponent.
+
+     Type: pow :: Int -> Int -> Int
+
+     Example:
+       pow 2 3
+       => 8
+
+       pow 6 4
+       => 1296
+  */
+  pow = base: exponent:
+    # I'll just make this linearly recursive instead.
+    let
+      iter = product: counter: max-count:
+        if counter > max-count
+        then product
+        else (iter (product * base) (counter + 1) max-count);
+    in
+    iter 1 1 exponent;
 }

subprojects/bahaghari/tests/lib/trivial/default.nix

@@ -77,6 +77,20 @@ pkgs.lib.runTests {
     expected = customBase24Glyphs;
   };
 
+  testGenerateConversionTable = {
+    expr = lib.trivial.generateConversionTable [ "A" "B" "C" "D" "E" "F" "G" "H" ];
+    expected = {
+      "A" = 0;
+      "B" = 1;
+      "C" = 2;
+      "D" = 3;
+      "E" = 4;
+      "F" = 5;
+      "G" = 6;
+      "H" = 7;
+    };
+  };
+
   testBaseDigitWithCustomOctalGlyph = {
     expr = lib.trivial.toBaseDigitsWithGlyphs 8 9 customOctalGlyphs;
     expected = "BB";
@@ -143,4 +157,9 @@ pkgs.lib.runTests {
     expr = lib.trivial.toYAML { } { hello = "there"; };
     expected = "{\"hello\":\"there\"}";
   };
+
+  testPow = {
+    expr = lib.trivial.pow 2 8;
+    expected = 256;
+  };
 }