Optimize typography and spacing modifier key patterns (#472)

* Optimize typography and spacing modifier key patterns

* Change spacings pattern

Author: emilisb

src/style/spacings.js

@@ -13,13 +13,19 @@ class Spacings {
   s9 = Constants.isIOS ? 27 : 36;
   s10 = Constants.isIOS ? 30 : 40;
 
+  keysPattern = this.generateKeysPattern();
+
   loadSpacings(spacings) {
     _.forEach(spacings, (value, key) => {
       this[key] = value;
     });
   }
 
   getKeysPattern() {
+    return this.keysPattern;
+  }
+
+  generateKeysPattern() {
     return new RegExp(
       _.chain(this)
         .keys()

src/style/typography.js

@@ -75,6 +75,8 @@ class Typography {
     fontFamily: Constants.isAndroid ? 'sans-serif-light' : undefined,
   };
 
+  keysPattern = this.generateKeysPattern();
+
   /**
    * Load custom set of typographies
    * arguments:
@@ -85,9 +87,14 @@ class Typography {
     _.forEach(typographies, (value, key) => {
       this[key] = value;
     });
+    this.keysPattern = this.generateKeysPattern();
   }
 
   getKeysPattern() {
+    return this.keysPattern;
+  }
+
+  generateKeysPattern() {
     return new RegExp(_.chain(this)
         .keys()
         .map(key => [`${key}`])