add the concept of widgets and widget fields

shared/naturalcrit/codeEditor/helpers/widget-elements/constants.js

@@ -0,0 +1,23 @@
+export const UNITS = ['cm', 'mm', 'in', 'px', 'pt', 'pc', 'em', 'ex', 'ch', 'rem', 'vw', 'vh', 'vmin', 'vmax', '%'];
+
+export const WIDGET_TYPE = {
+	SNIPPET        : 0,
+	INLINE_SNIPPET : 1,
+	IMAGE          : 2,
+};
+
+export const FIELD_TYPE = {
+	STYLE : 0
+};
+
+export const PATTERNS = {
+	widget : {
+		[WIDGET_TYPE.SNIPPET]        : (name)=>new RegExp(`^{{${name}(?:[^a-zA-Z].*)?`),
+		[WIDGET_TYPE.INLINE_SNIPPET] : (name)=>new RegExp(`{{${name}`),
+		[WIDGET_TYPE.IMAGE]          : ()=>new RegExp(`^\\!\\[(?:[a-zA-Z -]+)?\\]\\(.*\\).*{[a-zA-Z0-9:, "'-]+}$`),
+	},
+	field : {
+		[FIELD_TYPE.STYLE] : (name)=>new RegExp(`[{,;](${name}):((?:"[^},;"]*")|(?:[^},;]*))`),
+	},
+	collectStyles : new RegExp(`(?:[{,;]([a-zA-Z-]+):)+`, 'g'),
+};