Rename anglicus to arabicus

src/miscella/numerator.ts

@@ -0,0 +1,85 @@
+import RomanNumeral from 'js-roman-numerals';
+
+type Par = {
+  arabicus: number,
+  latinum: string;
+};
+
+export default class Numerator {
+  static minimus: Par = {
+    arabicus: 0.0,
+    latinum: 'N'
+  };
+
+  static maximus: Par = {
+    arabicus: 39993999.0 + (11.0 / 12.0),
+    latinum: '|MMMCMXCIX|MMMCMXCIXS×'
+  };
+
+  static fracti (): Map<number, string> {
+    const numeri: Map<number, string> = new Map;
+    numeri.set(1, '·');
+    numeri.set(2, ':');
+    numeri.set(3, '∴');
+    numeri.set(4, '::');
+    numeri.set(5, '×');
+    numeri.set(6, 'S');
+    numeri.set(7, 'S·');
+    numeri.set(8, 'S:');
+    numeri.set(9, 'S∴');
+    numeri.set(10, 'S::');
+    numeri.set(11, 'S×');
+    return numeri;
+  }
+
+  static convertibilis (arabicus: number): boolean {
+    return [
+      arabicus >= Numerator.minimus.arabicus,
+      arabicus <= Numerator.maximus.arabicus
+    ].all();
+  }
+
+  static romanus (arabicus: number): string {
+    if (this.convertibilis(arabicus)) {
+      if (arabicus === Numerator.minimus.arabicus) {
+        return Numerator.minimus.latinum;
+      } else if (Number.isInteger(arabicus)) {
+        if (arabicus >= 4000) {
+          const inferior: number = arabicus % 4000;
+          const superior: number = (arabicus - inferior) / 1000;
+          return `|${new RomanNumeral(superior)}|${new RomanNumeral(inferior)}`;
+        } else {
+          return new RomanNumeral(arabicus).toString();
+        }
+      } else {
+        const integer: number = Math.floor(arabicus);
+        const fractus: number = 12 * (arabicus - integer);
+        const fractum: string | undefined = this.fracti().get(fractus);
+        return fractum ? this.romanus(integer).concat(fractum) : '';
+      }
+    } else {
+      throw new Error(`Iacta interfuturu'st valor: ${arabicus}`);
+    }
+  }
+
+  static arabicus (romanus: string): number {
+    const fractus: string = [
+      ...this.fracti().values()
+    ].first(valor => romanus.includes(valor))[0];
+    if (fractus) {
+      const numerator: number = [
+        ...this.fracti().entries()
+      ].first(valor => valor[ 1 ] === fractus)[0];
+      romanus = romanus.replace(fractus, '');
+      return this.arabicus(romanus) + (numerator / 12.0);
+    } else if (romanus === 'N') {
+      return 0;
+    } else if (romanus.startsWith('|')) {
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      const [ _, superior, inferior ] = romanus.split('|');
+      return (10 * this.arabicus(superior)) + this.arabicus(inferior);
+    } else {
+      return new RomanNumeral(romanus).toInt();
+    }
+  }
+}