import { setFlagsFromString } from "v8";
import G from "@cafetextual/util/dist/src/type/G";

/**
 * Mostly extracting methods to prevent circular dependancies with flexJS doesn't like
 */
export default class GrammarCompilerHelper
{

	
	
	
	/**
	 * Creates a vector, or reuses an existing one, then appends content of additional vectors to it
	 */
	static mergeTokens(existing:Array<string> = null, v1:any = null, v2:any = null):Array<string> {
		var out:Array<string> = existing ? existing : new Array<string>();			
		var s:string;
		
		if (v1) {
			if (G.isArr(v1)) {
				this.mergeArray(out, v1 as Array<string>);

			} else if (G.isStr(v1) && (v1 as string).length > 0 && out.indexOf(v1) < 0)  {
				out.push(v1);
			}
		}
		
		
		if (v2) {
			if (G.isArr(v2)) {
				this.mergeArray(out, v2 as Array<string>);
			} else if (G.isStr(v2) && (v2 as string).length > 0 && out.indexOf(v2) < 0) {
				out.push(v2);
			}
		}
		return out;
	} // mergeTokens 
	

	
	
	static mergeArray(out:Array<string>, v:Array<string>, backwards:boolean = false):void {
		if (backwards) {
			for (var i:number = v.length -1; i>=0;i--) {
				var sv:string = v[i];
				if (out.indexOf(sv) < 0) {
					out.push(sv);
				}
			}
		}
		var s:string
		for (s of v) {
			if (out.indexOf(s) < 0) {
				out.push(s);
			}
		}
	}
	
	

	
} // class