application/vnd.ms-powerpoint=powerpoint\n\
application/vnd.openxmlformats-officedocument.presentationml.presentation=powerpoint\n\
application/vnd.oasis.opendocument.text=odt\n\
application/vnd.oasis.opendocument.spreadsheet=ods\n\
application/vnd.oasis.opendocument.presentation=odp\n\
application/pdf=pdf\n\
application/x-fictionbook+xml=fb2\n\
application/e-pub+zip=epub\n\
application/x-ibooks+zip=ibooks\n\

	}

	if !s.seenMutation {
		s.seenMutation = mayModifyPkgVar(rhs)
	}

	if allBlank(lhs) && !AnySideEffects(rhs) {
		return true // discard
	}

	// Only worry about simple "l = r" assignments. The OAS2*
	// assignments mostly necessitate dynamic execution anyway.
	if len(lhs) > 1 {
		return false
	}

	lno := ir.SetPos(n)
	defer func() { base.Pos = lno }()

	nam := lhs[0].(*ir.Name)

		tcAssign(n)

		// Code that creates temps does not bother to set defn, so do it here.
		if n.X.Op() == ir.ONAME && ir.IsAutoTmp(n.X) {
			n.X.Name().Defn = n
		}
		return n

	case ir.OAS2:
		tcAssignList(n.(*ir.AssignListStmt))
		return n

	case ir.OBREAK,
		ir.OCONTINUE,
		ir.ODCL,
		ir.OGOTO,
		ir.OFALL:
		return n

	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)

			as := typecheck.Stmt(ir.NewAssignStmt(n.Pos(), l1, r))
			o.mapAssign(as)
			o.popTemp(t)
			return
		}

		o.mapAssign(n)
		o.popTemp(t)

	case ir.OAS2:
		n := n.(*ir.AssignListStmt)
		t := o.markTemp()
		o.exprList(n.Lhs)
		o.exprList(n.Rhs)
		o.out = append(o.out, n)
		o.popTemp(t)

	// Special: avoid copy of func call n.Right
	case ir.OAS2FUNC:

	}
}

// appendWalkStmt typechecks and walks stmt and then appends it to init.
func appendWalkStmt(init *ir.Nodes, stmt ir.Node) {
	op := stmt.Op()
	n := typecheck.Stmt(stmt)
	if op == ir.OAS || op == ir.OAS2 {
		// If the assignment has side effects, walkExpr will append them
		// directly to init for us, while walkStmt will wrap it in an OBLOCK.
		// We need to append them directly.
		// TODO(rsc): Clean this up.

		// The concrete cases can all be handled without a runtime call.
		if len(concreteCases) > 0 {
			var clauses []typeClause
			for _, c := range concreteCases {
				as := ir.NewAssignListStmt(c.pos, ir.OAS2,
					[]ir.Node{ir.BlankNode, s.okName},                               // _, ok =
					[]ir.Node{ir.NewTypeAssertExpr(c.pos, s.srcName, c.typ.Type())}) // iface.(type)
				nif := ir.NewIfStmt(c.pos, s.okName, []ir.Node{c.jmp}, nil)

		n.Rhs = []ir.Node{r}
		return n
	}
	init.Append(r)

	ll := ascompatet(n.Lhs, r.Type())
	return ir.NewBlockStmt(src.NoXPos, ll)
}

// walkAssignList walks an OAS2 node.
func walkAssignList(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
	init.Append(ir.TakeInit(n)...)
	return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs))
}

	case ir.OCFUNC:
		return n

	case ir.OCALLINTER, ir.OCALLFUNC:
		n := n.(*ir.CallExpr)
		return walkCall(n, init)

	case ir.OAS, ir.OASOP:
		return walkAssign(init, n)

	case ir.OAS2:
		n := n.(*ir.AssignListStmt)
		return walkAssignList(init, n)

	// a,b,... = fn()
	case ir.OAS2FUNC:
		n := n.(*ir.AssignListStmt)
		return walkAssignFunc(init, n)

	// x, y = <-c

		call := mkcall1(fn.Nname, fn.Type().ResultsTuple(), init, ir.NewInt(base.Pos, sliceType.Elem().Size()), typecheck.Conv(typecheck.Conv(len, lenType), types.Types[types.TUINTPTR]))
		appendWalkStmt(init, ir.NewAssignListStmt(base.Pos, ir.OAS2, []ir.Node{mem, overflow}, []ir.Node{call}))

		// if overflow || mem > -uintptr(ptr) {
		//     if ptr == nil {
		//         panicunsafesliceptrnil()
		//     }
		//     panicunsafeslicelen()
		// }