basic for loop + examples -> era3

core/parser.go

@@ -383,6 +383,38 @@ func (p *Parser) expression(mustBeBlock bool) (Node, error) {
 			p.prev.End,
 		}, nil
 
+	case TokenFor:
+		p.advance()
+		start := p.prev.Start
+
+		counter, err := p.expression(false)
+		if err != nil {
+			return nil, err
+		}
+
+		if err := p.expect(TokenIn, "for-loops must be for each item in an iterator"); err != nil {
+			return nil, err
+		}
+
+		iterator, err := p.expression(false)
+		if err != nil {
+			return nil, err
+		}
+
+		logic, err := p.expression(true)
+		if err != nil {
+			return nil, err
+		}
+
+		return &ForNode{
+			counter,
+			iterator,
+			logic,
+
+			start,
+			p.prev.End,
+		}, nil
+
 	default:
 		s, err := p.binary()
 		if err != nil {