1 files changed, 126 insertions, 0 deletions
diff --git a/ext/bg/deinflector.js b/ext/bg/deinflector.js
new file mode 100644
index 00000000..03f9d40a
--- /dev/null
+++ b/ext/bg/deinflector.js
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2016  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+class Deinflection {
+    constructor(term, tags=[], rule='') {
+        this.children = [];
+        this.term     = term;
+        this.tags     = tags;
+        this.rule     = rule;
+    }
+
+    validate(validator) {
+        for (const tags of validator(this.term)) {
+            if (this.tags.length === 0) {
+                return true;
+            }
+
+            for (const tag of this.tags) {
+                if (this.searchTags(tag, tags)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    deinflect(validator, rules) {
+        if (this.validate(validator)) {
+            const child = new Deinflection(this.term);
+            this.children.push(child);
+        }
+
+        for (const rule in rules) {
+            const variants = rules[rule];
+            for (const v of variants) {
+                let allowed = this.tags.length === 0;
+                for (const tag of this.tags) {
+                    if (this.searchTags(tag, v.tagsIn)) {
+                        allowed = true;
+                        break;
+                    }
+                }
+
+                if (!allowed || !this.term.endsWith(v.kanaIn)) {
+                    continue;
+                }
+
+                const term = this.term.slice(0, -v.kanaIn.length) + v.kanaOut;
+                const child = new Deinflection(term, v.tagsOut, rule);
+                if (child.deinflect(validator, rules)) {
+                    this.children.push(child);
+                }
+            }
+        }
+
+        return this.children.length > 0;
+    }
+
+    searchTags(tag, tags) {
+        for (const t of tags) {
+            const re = new RegExp(tag);
+            if (re.test(t)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    gather() {
+        if (this.children.length === 0) {
+            return [{root: this.term, rules: []}];
+        }
+
+        const paths = [];
+        for (const child of this.children) {
+            for (const path of child.gather()) {
+                if (this.rule.length > 0) {
+                    path.rules.push(this.rule);
+                }
+
+                path.source = this.term;
+                paths.push(path);
+            }
+        }
+
+        return paths;
+    }
+}
+
+
+class Deinflector {
+    constructor() {
+        this.rules = {};
+    }
+
+    setRules(rules) {
+        this.rules = rules;
+    }
+
+    deinflect(term, validator) {
+        const node = new Deinflection(term);
+        if (node.deinflect(validator, this.rules)) {
+            return node.gather();
+        }
+
+        return null;
+    }
+}