}

            class TestGrammar extends Parser;

            options {
                buildAST = true;
            }

            expr:   mexpr (PLUS^ mexpr)* SEMI!
                ;

            mexpr
                :   atom (STAR^ atom)*
                ;

            atom:   INT
                ;"""

        file("grammar-builder/src/main/antlr/AnotherGrammar.g") << """

        header {
            package org.acme;
        }

        class TestGrammar extends Parser;

        options {
            buildAST = true;
        }

        expr:   mexpr (PLUS^ mexpr)* SEMI!
            ;

        mexpr
            :   atom (STAR^ atom)*
            ;

        atom:   INT
            ;"""
        expect:

        projectDir.file("src/main/antlr/org/acme/TestGrammar.g") << """ class TestGrammar extends Parser;
        options {
            buildAST = true;
        }

        expr:   mexpr (PLUS^ mexpr)* SEMI!
        ;

        mexpr
        :   atom (STAR^ atom)*
        ;

        atom:   INT
        ;"""
        projectDir.file("build.gradle") << """
            apply plugin: "antlr"

        and:

        file("src/main/antlr/org/acme/TestGrammar.g") << """ class TestGrammar extends Parser;
        options {
            buildAST = true;
        }

        expr:   mexpr (PLUS^ mexpr)* SEMI!
        ;

        mexpr
        :   atom (STAR^ atom)*
        ;

        atom:   INT
        ;"""

        when:
        succeeds("generateGrammarSource")

        then:

	return andArg(x.X) + " && " + andArg(x.Y)
}

func andArg(x Expr) string {
	s := x.String()
	if _, ok := x.(*OrExpr); ok {
		s = "(" + s + ")"
	}
	return s
}

func and(x, y Expr) Expr {
	return &AndExpr{x, y}
}

// An OrExpr represents the expression X || Y.
type OrExpr struct {
	X, Y Expr
}

func (x *OrExpr) isExpr() {}

	}
	return n
}

// tcSlice typechecks an OSLICE or OSLICE3 node.
func tcSlice(n *ir.SliceExpr) ir.Node {
	n.X = DefaultLit(Expr(n.X), nil)
	n.Low = indexlit(Expr(n.Low))
	n.High = indexlit(Expr(n.High))
	n.Max = indexlit(Expr(n.Max))
	hasmax := n.Op().IsSlice3()
	l := n.X
	if l.Type() == nil {
		n.SetType(nil)
		return n
	}
	if l.Type().IsArray() {

func (check *Checker) binary(x *operand, e syntax.Expr, lhs, rhs syntax.Expr, op syntax.Operator) {
	var y operand

	check.expr(nil, x, lhs)
	check.expr(nil, &y, rhs)

	if x.mode == invalid {
		return
	}
	if y.mode == invalid {
		x.mode = invalid
		x.expr = y.expr
		return
	}

	if isShift(op) {
		check.shift(x, &y, e, op)
		return
	}

func (check *Checker) binary(x *operand, e ast.Expr, lhs, rhs ast.Expr, op token.Token, opPos token.Pos) {
	var y operand

	check.expr(nil, x, lhs)
	check.expr(nil, &y, rhs)

	if x.mode == invalid {
		return
	}
	if y.mode == invalid {
		x.mode = invalid
		x.expr = y.expr
		return
	}

	if isShift(op) {
		check.shift(x, &y, e, op)
		return
	}

			return n
		}
		a := ir.Copy(n).(*ir.UnaryExpr)
		a.X = l
		return walkExpr(typecheck.Expr(a), init)

	case ir.ODOT, ir.ODOTPTR:
		n := n.(*ir.SelectorExpr)
		l := safeExpr(n.X, init)
		if l == n.X {
			return n
		}
		a := ir.Copy(n).(*ir.SelectorExpr)
		a.X = l
		return walkExpr(typecheck.Expr(a), init)

	case ir.ODEREF:
		n := n.(*ir.StarExpr)
		l := safeExpr(n.X, init)
		if l == n.X {

// Avoid excessive type-checking times due to quadratic termlist operations.
const maxTermCount = 100

// parseUnion parses uexpr as a union of expressions.
// The result is a Union type, or Typ[Invalid] for some errors.
func parseUnion(check *Checker, uexpr syntax.Expr) Type {
	blist, tlist := flattenUnion(nil, uexpr)
	assert(len(blist) == len(tlist)-1)

	var terms []*Term

	var u Type
	for i, x := range tlist {