func derivReturn(refs ast.RefLookup, p *ast.Pattern, patterns []*ast.Pattern) (*ast.Pattern, []*ast.Pattern) {
typ := p.GetValue()
switch v := typ.(type) {
case *ast.Empty:
return ast.NewNot(ast.NewZAny()), patterns
case *ast.ZAny:
return ast.NewZAny(), patterns
case *ast.TreeNode:
if Nullable(refs, patterns[0]) {
return ast.NewEmpty(), patterns[1:]
}
return ast.NewNot(ast.NewZAny()), patterns[1:]
case *ast.LeafNode:
if Nullable(refs, patterns[0]) {
return ast.NewEmpty(), patterns[1:]
}
return ast.NewNot(ast.NewZAny()), patterns[1:]
case *ast.Concat:
l, leftRest := derivReturn(refs, v.GetLeftPattern(), patterns)
leftConcat := ast.NewConcat(l, v.GetRightPattern())
if !Nullable(refs, v.GetLeftPattern()) {
return leftConcat, leftRest
}
r, rightRest := derivReturn(refs, v.GetRightPattern(), leftRest)
return ast.NewOr(leftConcat, r), rightRest
case *ast.Or:
l, leftRest := derivReturn(refs, v.GetLeftPattern(), patterns)
r, rightRest := derivReturn(refs, v.GetRightPattern(), leftRest)
return ast.NewOr(l, r), rightRest
case *ast.And:
l, leftRest := derivReturn(refs, v.GetLeftPattern(), patterns)
r, rightRest := derivReturn(refs, v.GetRightPattern(), leftRest)
return ast.NewAnd(l, r), rightRest
case *ast.Interleave:
l, leftRest := derivReturn(refs, v.GetLeftPattern(), patterns)
r, rightRest := derivReturn(refs, v.GetRightPattern(), leftRest)
return ast.NewOr(ast.NewInterleave(l, v.GetRightPattern()), ast.NewInterleave(r, v.GetLeftPattern())), rightRest
case *ast.ZeroOrMore:
c, rest := derivReturn(refs, v.GetPattern(), patterns)
return ast.NewConcat(c, p), rest
case *ast.Reference:
return derivReturn(refs, refs[v.GetName()], patterns)
case *ast.Not:
c, rest := derivReturn(refs, v.GetPattern(), patterns)
return ast.NewNot(c), rest
case *ast.Contains:
return derivReturn(refs, ast.NewConcat(ast.NewZAny(), ast.NewConcat(v.GetPattern(), ast.NewZAny())), patterns)
case *ast.Optional:
return derivReturn(refs, ast.NewOr(v.GetPattern(), ast.NewEmpty()), patterns)
}
panic(fmt.Sprintf("unknown pattern typ %T", typ))
}
func simplifyAnd(refs ast.RefLookup, p1, p2 *ast.Pattern, record bool) *ast.Pattern {
if isNotZany(p1) || isNotZany(p2) {
return emptyset
}
if isZany(p1) {
return p2
}
if isZany(p2) {
return p1
}
if isEmpty(p1) {
if Nullable(refs, p2) {
return ast.NewEmpty()
} else {
return emptyset
}
}
if isEmpty(p2) {
if Nullable(refs, p1) {
return ast.NewEmpty()
} else {
return emptyset
}
}
if p1.GetLeafNode() != nil && p2.GetLeafNode() != nil {
expr1, err1 := compose.ConvertBuiltInIntoFunction(p1.GetLeafNode().GetExpr())
expr2, err2 := compose.ConvertBuiltInIntoFunction(p2.GetLeafNode().GetExpr())
if err1 == nil && err2 == nil {
return ast.NewLeafNode(ast.NewFunction("and", expr1, expr2))
}
}
left := getAnds(p1)
right := getAnds(p2)
list := append(left, right...)
list = ast.Set(list)
list = simplifyChildren(list, func(left, right *ast.Pattern) *ast.Pattern {
return simplifyAnd(refs, left, right, record)
}, record)
ast.Sort(list)
var p *ast.Pattern = list[0]
for i := range list {
if i == 0 {
continue
}
p = ast.NewAnd(p, list[i])
}
return p
}
func newList(nameOrPattern *NameOrPattern) *ast.Pattern {
regexStr, nullable, err := listToRegex(nameOrPattern)
if err != nil {
return ast.NewNot(ast.NewZAny())
}
val := combinator.Value(&list{nil, funcs.StringVar(), funcs.StringConst("^" + regexStr + "$")})
if !nullable {
return val
}
return ast.NewOr(val, ast.NewEmpty())
}
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 simplifyOptional(p *ast.Pattern) *ast.Pattern {
if isEmpty(p) {
return ast.NewEmpty()
}
return ast.NewOptional(p)
}
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))
}
func newT(s string) *ast.Pattern {
return ast.NewTreeNode(ast.NewStringName(s), ast.NewEmpty())
}
