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))
}
func simplifyOptional(p *ast.Pattern) *ast.Pattern {
if isEmpty(p) {
return ast.NewEmpty()
}
return ast.NewOptional(p)
}