Example #1
0
func (this *nameToNumber) translate(context *context, p *ast.Pattern) (*ast.Pattern, error) {
	typ := p.GetValue()
	switch v := typ.(type) {
	case *ast.Empty, *ast.LeafNode, *ast.ZAny:
		return p, nil
	case *ast.TreeNode:
		return this.translateName(context, v.GetName(), v.GetPattern())
	case *ast.Concat:
		l, err1 := this.translate(context, v.GetLeftPattern())
		r, err2 := this.translate(context, v.GetRightPattern())
		return ast.NewConcat(l, r), anyErr(err1, err2)
	case *ast.Or:
		l, err1 := this.translate(context, v.GetLeftPattern())
		r, err2 := this.translate(context, v.GetRightPattern())
		return ast.NewOr(l, r), anyErr(err1, err2)
	case *ast.And:
		l, err1 := this.translate(context, v.GetLeftPattern())
		r, err2 := this.translate(context, v.GetRightPattern())
		return ast.NewAnd(l, r), anyErr(err1, err2)
	case *ast.ZeroOrMore:
		p, err := this.translate(context, v.GetPattern())
		return ast.NewZeroOrMore(p), err
	case *ast.Reference:
		c, ok := this.refs[v.GetName()]
		if !ok {
			this.refs[v.GetName()] = context
			return p, nil
		}
		if !c.Equal(context) {
			//TODO we could probably create a new reference here
			//  for every conflicting combination of msg x repeated x referece name
			return nil, &ErrDup{v.GetName(), c, context}
		}
		return p, nil
	case *ast.Not:
		p, err := this.translate(context, v.GetPattern())
		return ast.NewNot(p), err
	case *ast.Contains:
		p, err := this.translate(context, v.GetPattern())
		return ast.NewContains(p), err
	case *ast.Optional:
		p, err := this.translate(context, v.GetPattern())
		return ast.NewOptional(p), err
	case *ast.Interleave:
		l, err1 := this.translate(context, v.GetLeftPattern())
		r, err2 := this.translate(context, v.GetRightPattern())
		return ast.NewInterleave(l, r), anyErr(err1, err2)
	}
	panic(fmt.Sprintf("unknown pattern typ %T", typ))
}
Example #2
0
func simplifyOptional(p *ast.Pattern) *ast.Pattern {
	if isEmpty(p) {
		return ast.NewEmpty()
	}
	return ast.NewOptional(p)
}