func derivCall(refs map[string]*ast.Pattern, getFunc func(*ast.Expr) funcs.Bool, p *ast.Pattern) []*ifExpr {
typ := p.GetValue()
switch v := typ.(type) {
case *ast.Empty:
return []*ifExpr{}
case *ast.ZAny:
return []*ifExpr{}
case *ast.TreeNode:
b := nameexpr.NameToFunc(v.GetName())
return []*ifExpr{{b, v.GetPattern(), ast.NewNot(ast.NewZAny())}}
case *ast.LeafNode:
b := getFunc(v.GetExpr())
return []*ifExpr{{b, ast.NewEmpty(), ast.NewNot(ast.NewZAny())}}
case *ast.Concat:
l := derivCall(refs, getFunc, v.GetLeftPattern())
if !interp.Nullable(refs, v.GetLeftPattern()) {
return l
}
r := derivCall(refs, getFunc, v.GetRightPattern())
return append(l, r...)
case *ast.Or:
return derivCall2(refs, getFunc, v.GetLeftPattern(), v.GetRightPattern())
case *ast.And:
return derivCall2(refs, getFunc, v.GetLeftPattern(), v.GetRightPattern())
case *ast.Interleave:
return derivCall2(refs, getFunc, v.GetLeftPattern(), v.GetRightPattern())
case *ast.ZeroOrMore:
return derivCall(refs, getFunc, v.GetPattern())
case *ast.Reference:
return derivCall(refs, getFunc, refs[v.GetName()])
case *ast.Not:
return derivCall(refs, getFunc, v.GetPattern())
case *ast.Contains:
return derivCall(refs, getFunc, ast.NewConcat(ast.NewZAny(), ast.NewConcat(v.GetPattern(), ast.NewZAny())))
case *ast.Optional:
return derivCall(refs, getFunc, ast.NewOr(v.GetPattern(), ast.NewEmpty()))
}
panic(fmt.Sprintf("unknown pattern typ %T", typ))
}
func (this *simplifier) simplify(p *ast.Pattern, top bool) *ast.Pattern {
cRef := func(cp *ast.Pattern) *ast.Pattern {
if top {
return cp
}
return checkRef(this.refs, cp)
}
cachesimp := func(sp *ast.Pattern) *ast.Pattern {
if _, ok := this.cache[sp]; ok {
return sp
}
s := this.simplify(sp, false)
this.cache[s] = struct{}{}
return s
}
simp := func(sp *ast.Pattern) *ast.Pattern {
return this.simplify(sp, false)
}
typ := p.GetValue()
switch v := typ.(type) {
case *ast.Empty:
return p
case *ast.TreeNode:
child := cachesimp(v.GetPattern())
if isNotZany(child) {
return emptyset
}
name := v.GetName()
b := nameexpr.NameToFunc(v.GetName())
if funcs.IsFalse(b) {
return emptyset
}
if funcs.IsTrue(b) {
name = ast.NewAnyName()
}
return cRef(ast.NewTreeNode(name, child))
case *ast.LeafNode:
b, err := compose.NewBool(v.GetExpr())
if err != nil {
//Don't simplify if there is an error to keep this function signature simple.
return p
}
if funcs.IsFalse(b) {
return emptyset
}
return p
case *ast.Concat:
return cRef(simplifyConcat(
simp(v.GetLeftPattern()),
simp(v.GetRightPattern()),
))
case *ast.Or:
return cRef(simplifyOr(this.refs,
simp(v.GetLeftPattern()),
simp(v.GetRightPattern()),
this.record,
))
case *ast.And:
return cRef(simplifyAnd(this.refs,
simp(v.GetLeftPattern()),
simp(v.GetRightPattern()),
this.record,
))
case *ast.ZeroOrMore:
return cRef(simplifyZeroOrMore(simp(v.GetPattern())))
case *ast.Reference:
return p
case *ast.Not:
return cRef(simplifyNot(simp(v.GetPattern())))
case *ast.ZAny:
return p
case *ast.Contains:
return cRef(simplifyContains(simp(v.GetPattern())))
case *ast.Optional:
return simplifyOptional(simp(v.GetPattern()))
case *ast.Interleave:
return cRef(simplifyInterleave(this.refs,
cachesimp(v.GetLeftPattern()),
cachesimp(v.GetRightPattern()),
))
}
panic(fmt.Sprintf("unknown pattern typ %T", typ))
}
func derivCall(refs ast.RefLookup, p *ast.Pattern, label parser.Value) ([]*ast.Pattern, error) {
typ := p.GetValue()
switch v := typ.(type) {
case *ast.Empty:
return []*ast.Pattern{}, nil
case *ast.ZAny:
return []*ast.Pattern{}, nil
case *ast.TreeNode:
b := nameexpr.NameToFunc(v.GetName())
f, err := compose.NewBoolFunc(b)
if err != nil {
return nil, err
}
eval, err := f.Eval(label)
if err != nil {
return nil, err
}
if eval {
return []*ast.Pattern{v.GetPattern()}, nil
}
return []*ast.Pattern{ast.NewNot(ast.NewZAny())}, nil
case *ast.LeafNode:
b, err := compose.NewBool(v.GetExpr())
if err != nil {
return nil, err
}
f, err := compose.NewBoolFunc(b)
if err != nil {
return nil, err
}
eval, err := f.Eval(label)
if err != nil {
return nil, err
}
if eval {
return []*ast.Pattern{ast.NewEmpty()}, nil
}
return []*ast.Pattern{ast.NewNot(ast.NewZAny())}, nil
case *ast.Concat:
l, err := derivCall(refs, v.GetLeftPattern(), label)
if err != nil {
return nil, err
}
if !Nullable(refs, v.GetLeftPattern()) {
return l, nil
}
r, err := derivCall(refs, v.GetRightPattern(), label)
if err != nil {
return nil, err
}
return append(l, r...), nil
case *ast.Or:
return derivCall2(refs, v.GetLeftPattern(), v.GetRightPattern(), label)
case *ast.And:
return derivCall2(refs, v.GetLeftPattern(), v.GetRightPattern(), label)
case *ast.Interleave:
return derivCall2(refs, v.GetLeftPattern(), v.GetRightPattern(), label)
case *ast.ZeroOrMore:
return derivCall(refs, v.GetPattern(), label)
case *ast.Reference:
return derivCall(refs, refs[v.GetName()], label)
case *ast.Not:
return derivCall(refs, v.GetPattern(), label)
case *ast.Contains:
return derivCall(refs, ast.NewConcat(ast.NewZAny(), ast.NewConcat(v.GetPattern(), ast.NewZAny())), label)
case *ast.Optional:
return derivCall(refs, ast.NewOr(v.GetPattern(), ast.NewEmpty()), label)
}
panic(fmt.Sprintf("unknown pattern typ %T", typ))
}