[client] exeute command

client/src/bfExecutor.ts

@@ -0,0 +1,117 @@
+import { AbstractParseTreeVisitor } from 'antlr4ts/tree/AbstractParseTreeVisitor';
+import { LoopStmtContext, ProgramContext } from '../../client/src/generated/bfParser';
+import { bfVisitor } from '../../client/src/generated/bfVisitor';
+import {getTree} from './bfGrammar';
+import { DiagnosticSeverity } from 'vscode-languageserver-types';
+
+/**
+ * Run BF code
+ * @param text 
+ * @param fn 
+ * @param input 
+ * @returns 
+ */
+export async function runBF(text:string,fn:string,input:string){
+	//get tree and issues
+	const {tree,issues} = getTree(text,fn);
+
+	//get only errors
+	const x = issues.filter(e=>e.type===DiagnosticSeverity.Error);
+	//if any error, drop
+	if(x.length>0) {
+		throw Error('Errors exist');
+	}
+	// make visitor
+	const vis = new BFExecutor(input);
+	
+	//visit the tree
+	vis.visit(tree);
+
+	//get output
+	return vis.outputStr;
+}
+
+
+class BFExecutor
+	extends AbstractParseTreeVisitor<void>
+	implements bfVisitor<void> {
+
+	/**
+	 * 
+	 * @param input Input string
+	 * @param inputPtr Input pointer to start from
+	 */
+	constructor(protected input: string='', protected inputPtr: number = 0) {
+		super();
+	}
+	/**
+	 * The memory cells (Can work with negative cells this way)
+	 */
+    protected cells: Map<number, number> = new Map();
+    /**
+	 * Pointer
+	 */
+	protected ptr: number = 0;
+	/** Output string */
+	protected outputStrArray:string[]=[];
+
+	/**
+	 * Output string (Available only after visiting)
+	 */
+	public get outputStr(){
+		return this.outputStrArray.join('');
+	}
+
+
+	defaultResult() {}
+
+	visitLoopStmt(ctx:LoopStmtContext){
+		while((this.cells.get(this.ptr)??0)!==0){
+			this.visitChildren(ctx);
+		}
+	}
+	visitPtrLeft() {
+		
+		--this.ptr;
+	}
+	visitPtrRight() {
+		++this.ptr;
+	}
+	visitPtrIncr() {
+
+    	const val = this.cells.get(this.ptr);
+    	if (val === undefined) {
+    		this.cells.set(this.ptr, 1);
+		} else if(val===255){
+			this.cells.delete(this.ptr);
+		}else{
+    		this.cells.set(this.ptr, val + 1);
+    	}
+	}
+	visitPtrDecr() {
+		// console.log('down',this.ptr,this.cells);
+
+    	const val = this.cells.get(this.ptr);
+    	if (val === undefined || val === 0) {
+    		this.cells.set(this.ptr, 255);
+    	} else if(val===1){
+			this.cells.delete(this.ptr);
+		}else{
+    		this.cells.set(this.ptr, val - 1);
+    	}
+	}
+	visitOutputStmt() {
+		const val = this.cells.get(this.ptr)??0;
+		const str = String.fromCharCode(val);
+		// console.log('op',str);
+		this.outputStrArray.push(str);
+	}
+
+	visitInputStmt(){
+		//get char
+		const char = this.input.charCodeAt(this.inputPtr)??0;
+		//increment the input pointer after this
+		this.inputPtr++;
+		this.cells.set(this.ptr,char);
+	}
+}