snapshot of https://github.com/cortezaproject/corteza.git (2024.9.x, 2026-09-18; blobs > 131072B omitted)

server/pkg/expr/path.go

@@ -0,0 +1,114 @@
+package expr
+
+type (
+	exprPath struct {
+		path   string
+		i      int
+		isLast bool
+
+		start, end int
+	}
+
+	Pather interface {
+		String() string
+		More() bool
+		IsLast() bool
+		Get() string
+		Rest() string
+		Next() (err error)
+	}
+)
+
+// Path initializes a new exprPath helper to efficiently traverse the path
+func Path(p string) (out *exprPath) {
+	return &exprPath{path: p}
+}
+
+func (p *exprPath) String() string {
+	return p.path
+}
+
+func (p *exprPath) More() bool {
+	return p.start < len(p.path)
+}
+
+func (p *exprPath) IsLast() bool {
+	return p.isLast
+}
+
+func (p *exprPath) Get() string {
+	return p.path[p.start:p.end]
+}
+
+func (p *exprPath) Rest() string {
+	var rest string
+	if p.end+1 < len(p.path) {
+		rest = p.path[p.end:]
+	}
+
+	// @todo this is fugly but it'll do the trick for now
+	// Clean it up please :)
+	if len(rest) > 0 && (rest[0] == '.' || rest[0] == ']') {
+		rest = rest[1:]
+	}
+	if len(rest) > 0 && (rest[0] == '.' || rest[0] == ']') {
+		rest = rest[1:]
+	}
+
+	return rest
+}
+
+func (p *exprPath) Next() (err error) {
+	if !p.More() {
+		return nil
+	}
+
+	if p.end > 0 {
+		p.start = p.end + 1
+	}
+
+	var ()
+
+	p.start, p.end, p.isLast, err = nxtRange(p.path, p.start)
+	if err != nil {
+		return err
+	}
+
+	p.i++
+
+	return nil
+}
+
+func nxtRange(path string, start int) (startOut, end int, isLast bool, err error) {
+	startOut = start
+	for i := start; i < len(path); i++ {
+		switch path[i] {
+		// This thing concludes the prev ident
+		case '.', '[':
+			if i == len(path)-1 {
+				return startOut, -1, false, invalidPathErr
+			}
+			if i > 0 {
+				if path[i-1] == ']' {
+					startOut++
+					continue
+				}
+			}
+			return startOut, i, false, nil
+
+		case ']':
+			// If we're at the end, that's that
+			if i == len(path)-1 {
+				return startOut, i, true, nil
+			}
+
+			if path[i+1] != '.' && path[i+1] != '[' {
+				return startOut, -1, false, invalidPathErr
+			} else {
+				return startOut, i, false, nil
+			}
+		}
+	}
+
+	return startOut, len(path), true, nil
+}