snapshot of https://github.com/blevesearch/bleve.git (master, 2026-09-15; blobs > 131072B omitted)

analysis/lang/pl/stempel/multi_trie.go

@@ -0,0 +1,140 @@
+//  Copyright (c) 2018 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package stempel
+
+import (
+	"fmt"
+
+	"github.com/blevesearch/stempel/javadata"
+)
+
+// multiTrie represents a trie of tries.  When using the multiTrie, each trie
+// is consulted consecutively to find commands to perform on the input.  Thus
+// a multiTrie with seven tries might have up to seven groups of commands to
+// perform on the input.
+type multiTrie struct {
+	tries   []*trie
+	by      int32
+	forward bool
+}
+
+func newMultiTrie(r *javadata.Reader) (rv *multiTrie, err error) {
+	rv = &multiTrie{}
+	rv.forward, err = r.ReadBool()
+	if err != nil {
+		return nil, err
+	}
+	rv.by, err = r.ReadInt32()
+	if err != nil {
+		return nil, err
+	}
+	nTries, err := r.ReadInt32()
+	if err != nil {
+		return nil, err
+	}
+	for nTries > 0 {
+		trie, err := newTrie(r)
+		if err != nil {
+			return nil, err
+		}
+		rv.tries = append(rv.tries, trie)
+		nTries--
+	}
+	return rv, nil
+}
+
+const eom = rune('*')
+
+func (t *multiTrie) GetLastOnPath(key []rune) []rune {
+	var rv []rune
+	lastKey := key
+	p := make([][]rune, len(t.tries))
+	lastR := ' '
+	for i := 0; i < len(t.tries); i++ {
+		r := t.tries[i].GetLastOnPath(lastKey)
+		if len(r) == 0 || len(r) == 1 && r[0] == eom {
+			return rv
+		}
+		if cannotFollow(lastR, r[0]) {
+			return rv
+		}
+		lastR = r[len(r)-2]
+		p[i] = r
+		if p[i][0] == '-' {
+			if i > 0 {
+				var err error
+				key, err = t.skip(key, lengthPP(p[i-1]))
+				if err != nil {
+					return rv
+				}
+			}
+			var err error
+			key, err = t.skip(key, lengthPP(p[i]))
+			if err != nil {
+				return rv
+			}
+		}
+		rv = append(rv, r...)
+		if len(key) != 0 {
+			lastKey = key
+		}
+	}
+	return rv
+}
+
+func cannotFollow(after, goes rune) bool {
+	switch after {
+	case '-', 'D':
+		return after == goes
+	}
+	return false
+}
+
+var errIndexOutOfBounds = fmt.Errorf("index out of bounds")
+
+func (t *multiTrie) skip(in []rune, count int) ([]rune, error) {
+	if count > len(in) {
+		return nil, errIndexOutOfBounds
+	}
+	if t.forward {
+		return in[count:], nil
+	}
+	return in[0 : len(in)-count], nil
+}
+
+func lengthPP(cmd []rune) int {
+	rv := 0
+	for i := 0; i < len(cmd); i++ {
+		switch cmd[i] {
+		case '-', 'D':
+			i++
+			rv += int(cmd[i] - rune('a') + 1)
+		case 'R':
+			i++
+			rv++
+			fallthrough
+		case 'I':
+		}
+	}
+	return rv
+}
+
+func (t *multiTrie) String() string {
+	rv := ""
+	for i, trie := range t.tries {
+		rv += fmt.Sprintf("trie %d\n\n %v\n--------\n", i, trie)
+	}
+	return rv
+}