Merge pull request #279 from siikamiika/query-parser-1

Search page query parser

17 files changed, 693 insertions, 35 deletions

diff --git a/ext/bg/background.html b/ext/bg/background.html
index bbfbd1e1..6e6e7c26 100644
--- a/ext/bg/background.html
+++ b/ext/bg/background.html
@@ -21,6 +21,7 @@
         <script src="/mixed/js/extension.js"></script>
 
         <script src="/bg/js/anki.js"></script>
+        <script src="/bg/js/mecab.js"></script>
         <script src="/bg/js/api.js"></script>
         <script src="/bg/js/audio.js"></script>
         <script src="/bg/js/backend-api-forwarder.js"></script>
diff --git a/ext/bg/js/api.js b/ext/bg/js/api.js
index df73aa2a..766fb0ed 100644
--- a/ext/bg/js/api.js
+++ b/ext/bg/js/api.js
@@ -79,6 +79,71 @@ async function apiTermsFind(text, details, optionsContext) {
     return {length, definitions};
 }
 
+async function apiTextParse(text, optionsContext) {
+    const options = await apiOptionsGet(optionsContext);
+    const translator = utilBackend().translator;
+
+    const results = [];
+    while (text.length > 0) {
+        const term = [];
+        const [definitions, sourceLength] = await translator.findTermsInternal(
+            text.slice(0, options.scanning.length),
+            dictEnabledSet(options),
+            options.scanning.alphanumeric,
+            {}
+        );
+        if (definitions.length > 0) {
+            dictTermsSort(definitions);
+            const {expression, reading} = definitions[0];
+            const source = text.slice(0, sourceLength);
+            for (const {text, furigana} of jpDistributeFuriganaInflected(expression, reading, source)) {
+                const reading = jpConvertReading(text, furigana, options.parsing.readingMode);
+                term.push({text, reading});
+            }
+            text = text.slice(source.length);
+        } else {
+            const reading = jpConvertReading(text[0], null, options.parsing.readingMode);
+            term.push({text: text[0], reading});
+            text = text.slice(1);
+        }
+        results.push(term);
+    }
+    return results;
+}
+
+async function apiTextParseMecab(text, optionsContext) {
+    const options = await apiOptionsGet(optionsContext);
+    const mecab = utilBackend().mecab;
+
+    const results = {};
+    const rawResults = await mecab.parseText(text);
+    for (const mecabName in rawResults) {
+        const result = [];
+        for (const parsedLine of rawResults[mecabName]) {
+            for (const {expression, reading, source} of parsedLine) {
+                const term = [];
+                if (expression !== null && reading !== null) {
+                    for (const {text, furigana} of jpDistributeFuriganaInflected(
+                        expression,
+                        jpKatakanaToHiragana(reading),
+                        source
+                    )) {
+                        const reading = jpConvertReading(text, furigana, options.parsing.readingMode);
+                        term.push({text, reading});
+                    }
+                } else {
+                    const reading = jpConvertReading(source, null, options.parsing.readingMode);
+                    term.push({text: source, reading});
+                }
+                result.push(term);
+            }
+            result.push([{text: '\n'}]);
+        }
+        results[mecabName] = result;
+    }
+    return results;
+}
+
 async function apiKanjiFind(text, optionsContext) {
     const options = await apiOptionsGet(optionsContext);
     const definitions = await utilBackend().translator.findKanji(text, options);
diff --git a/ext/bg/js/backend.js b/ext/bg/js/backend.js
index efad153a..45db9660 100644
--- a/ext/bg/js/backend.js
+++ b/ext/bg/js/backend.js
@@ -21,6 +21,7 @@ class Backend {
     constructor() {
         this.translator = new Translator();
         this.anki = new AnkiNull();
+        this.mecab = new Mecab();
         this.options = null;
         this.optionsContext = {
             depth: 0,
@@ -97,6 +98,12 @@ class Backend {
         }
 
         this.anki = options.anki.enable ? new AnkiConnect(options.anki.server) : new AnkiNull();
+
+        if (options.parsing.enableMecabParser) {
+            this.mecab.startListener();
+        } else {
+            this.mecab.stopListener();
+        }
     }
 
     async getFullOptions() {
@@ -180,6 +187,8 @@ Backend.messageHandlers = {
     optionsSet: ({changedOptions, optionsContext, source}) => apiOptionsSet(changedOptions, optionsContext, source),
     kanjiFind: ({text, optionsContext}) => apiKanjiFind(text, optionsContext),
     termsFind: ({text, details, optionsContext}) => apiTermsFind(text, details, optionsContext),
+    textParse: ({text, optionsContext}) => apiTextParse(text, optionsContext),
+    textParseMecab: ({text, optionsContext}) => apiTextParseMecab(text, optionsContext),
     definitionAdd: ({definition, mode, context, optionsContext}) => apiDefinitionAdd(definition, mode, context, optionsContext),
     definitionsAddable: ({definitions, modes, optionsContext}) => apiDefinitionsAddable(definitions, modes, optionsContext),
     noteView: ({noteId}) => apiNoteView(noteId),
diff --git a/ext/bg/js/mecab.js b/ext/bg/js/mecab.js
new file mode 100644
index 00000000..246f8bba
--- /dev/null
+++ b/ext/bg/js/mecab.js
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2019  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 Mecab {
+    constructor() {
+        this.port = null;
+        this.listeners = {};
+        this.sequence = 0;
+    }
+
+    onError(error) {
+        logError(error, false);
+    }
+
+    async checkVersion() {
+        try {
+            const {version} = await this.invoke('get_version', {});
+            if (version !== Mecab.version) {
+                this.stopListener();
+                throw new Error(`Unsupported MeCab native messenger version ${version}. Yomichan supports version ${Mecab.version}.`);
+            }
+        } catch (error) {
+            this.onError(error);
+        }
+    }
+
+    async parseText(text) {
+        return await this.invoke('parse_text', {text});
+    }
+
+    startListener() {
+        if (this.port !== null) { return; }
+        this.port = chrome.runtime.connectNative('yomichan_mecab');
+        this.port.onMessage.addListener(this.onNativeMessage.bind(this));
+        this.checkVersion();
+    }
+
+    stopListener() {
+        if (this.port === null) { return; }
+        this.port.disconnect();
+        this.port = null;
+        this.listeners = {};
+        this.sequence = 0;
+    }
+
+    onNativeMessage({sequence, data}) {
+        if (this.listeners.hasOwnProperty(sequence)) {
+            const {callback, timer} = this.listeners[sequence];
+            clearTimeout(timer);
+            callback(data);
+            delete this.listeners[sequence];
+        }
+    }
+
+    invoke(action, params) {
+        if (this.port === null) {
+            return Promise.resolve({});
+        }
+        return new Promise((resolve, reject) => {
+            const sequence = this.sequence++;
+
+            this.listeners[sequence] = {
+                callback: resolve,
+                timer: setTimeout(() => {
+                    delete this.listeners[sequence];
+                    reject(new Error(`Mecab invoke timed out in ${Mecab.timeout} ms`));
+                }, Mecab.timeout)
+            }
+
+            this.port.postMessage({action, params, sequence});
+        });
+    }
+}
+
+Mecab.timeout = 5000;
+Mecab.version = 1;
diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index be1ccfbb..b9bf85f3 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -311,6 +311,13 @@ function profileOptionsCreateDefaults() {
 
         dictionaries: {},
 
+        parsing: {
+            enableScanningParser: true,
+            enableMecabParser: false,
+            selectedParser: null,
+            readingMode: 'hiragana'
+        },
+
         anki: {
             enable: false,
             server: 'http://127.0.0.1:8765',
diff --git a/ext/bg/js/search-query-parser.js b/ext/bg/js/search-query-parser.js
new file mode 100644
index 00000000..42e53989
--- /dev/null
+++ b/ext/bg/js/search-query-parser.js
@@ -0,0 +1,228 @@
+/*
+ * Copyright (C) 2019  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 QueryParser {
+    constructor(search) {
+        this.search = search;
+        this.pendingLookup = false;
+        this.clickScanPrevent = false;
+
+        this.parseResults = [];
+        this.selectedParser = null;
+
+        this.queryParser = document.querySelector('#query-parser');
+        this.queryParserSelect = document.querySelector('#query-parser-select');
+
+        this.queryParser.addEventListener('mousedown', (e) => this.onMouseDown(e));
+        this.queryParser.addEventListener('mouseup', (e) => this.onMouseUp(e));
+    }
+
+    onError(error) {
+        logError(error, false);
+    }
+
+    onMouseDown(e) {
+        if (Frontend.isMouseButton('primary', e)) {
+            this.clickScanPrevent = false;
+        }
+    }
+
+    onMouseUp(e) {
+        if (
+            this.search.options.scanning.clickGlossary &&
+            !this.clickScanPrevent &&
+            Frontend.isMouseButton('primary', e)
+        ) {
+            const selectText = this.search.options.scanning.selectText;
+            this.onTermLookup(e, {disableScroll: true, selectText});
+        }
+    }
+
+    onMouseMove(e) {
+        if (this.pendingLookup || Frontend.isMouseButton('primary', e)) {
+            return;
+        }
+
+        const scanningOptions = this.search.options.scanning;
+        const scanningModifier = scanningOptions.modifier;
+        if (!(
+            Frontend.isScanningModifierPressed(scanningModifier, e) ||
+            (scanningOptions.middleMouse && Frontend.isMouseButton('auxiliary', e))
+        )) {
+            return;
+        }
+
+        const selectText = this.search.options.scanning.selectText;
+        this.onTermLookup(e, {disableScroll: true, disableHistory: true, selectText});
+    }
+
+    onMouseLeave(e) {
+        this.clickScanPrevent = true;
+        clearTimeout(e.target.dataset.timer);
+        delete e.target.dataset.timer;
+    }
+
+    onTermLookup(e, params) {
+        this.pendingLookup = true;
+        (async () => {
+            await this.search.onTermLookup(e, params);
+            this.pendingLookup = false;
+        })();
+    }
+
+    onParserChange(e) {
+        const selectedParser = e.target.value;
+        this.selectedParser = selectedParser;
+        apiOptionsSet({parsing: {selectedParser}}, this.search.getOptionsContext());
+        this.renderParseResult(this.getParseResult());
+    }
+
+    refreshSelectedParser() {
+        if (this.parseResults.length > 0) {
+            if (this.selectedParser === null) {
+                this.selectedParser = this.search.options.parsing.selectedParser;
+            }
+            if (this.selectedParser === null || !this.getParseResult()) {
+                const selectedParser = this.parseResults[0].id;
+                this.selectedParser = selectedParser;
+                apiOptionsSet({parsing: {selectedParser}}, this.search.getOptionsContext());
+            }
+        }
+    }
+
+    getParseResult() {
+        return this.parseResults.find(r => r.id === this.selectedParser);
+    }
+
+    async setText(text) {
+        this.search.setSpinnerVisible(true);
+
+        await this.setPreview(text);
+
+        this.parseResults = await this.parseText(text);
+        this.refreshSelectedParser();
+
+        this.renderParserSelect();
+        await this.renderParseResult();
+
+        this.search.setSpinnerVisible(false);
+    }
+
+    async parseText(text) {
+        const results = [];
+        if (this.search.options.parsing.enableScanningParser) {
+            results.push({
+                name: 'Scanning parser',
+                id: 'scan',
+                parsedText: await apiTextParse(text, this.search.getOptionsContext())
+            });
+        }
+        if (this.search.options.parsing.enableMecabParser) {
+            let mecabResults = await apiTextParseMecab(text, this.search.getOptionsContext());
+            for (const mecabDictName in mecabResults) {
+                results.push({
+                    name: `MeCab: ${mecabDictName}`,
+                    id: `mecab-${mecabDictName}`,
+                    parsedText: mecabResults[mecabDictName]
+                });
+            }
+        }
+        return results;
+    }
+
+    async setPreview(text) {
+        const previewTerms = [];
+        while (text.length > 0) {
+            const tempText = text.slice(0, 2);
+            previewTerms.push([{text: Array.from(tempText)}]);
+            text = text.slice(2);
+        }
+        this.queryParser.innerHTML = await apiTemplateRender('query-parser.html', {
+            terms: previewTerms,
+            preview: true
+        });
+
+        for (const charElement of this.queryParser.querySelectorAll('.query-parser-char')) {
+            this.activateScanning(charElement);
+        }
+    }
+
+    renderParserSelect() {
+        this.queryParserSelect.innerHTML = '';
+        if (this.parseResults.length > 1) {
+            const select = document.createElement('select');
+            select.classList.add('form-control');
+            for (const parseResult of this.parseResults) {
+                const option = document.createElement('option');
+                option.value = parseResult.id;
+                option.innerText = parseResult.name;
+                option.defaultSelected = this.selectedParser === parseResult.id;
+                select.appendChild(option);
+            }
+            select.addEventListener('change', this.onParserChange.bind(this));
+            this.queryParserSelect.appendChild(select);
+        }
+    }
+
+    async renderParseResult() {
+        const parseResult = this.getParseResult();
+        if (!parseResult) {
+            this.queryParser.innerHTML = '';
+            return;
+        }
+
+        this.queryParser.innerHTML = await apiTemplateRender(
+            'query-parser.html',
+            {terms: QueryParser.processParseResultForDisplay(parseResult.parsedText)}
+        );
+
+        for (const charElement of this.queryParser.querySelectorAll('.query-parser-char')) {
+            this.activateScanning(charElement);
+        }
+    }
+
+    activateScanning(element) {
+        element.addEventListener('mousemove', (e) => {
+            clearTimeout(e.target.dataset.timer);
+            if (this.search.options.scanning.modifier === 'none') {
+                e.target.dataset.timer = setTimeout(() => {
+                    this.onMouseMove(e);
+                    delete e.target.dataset.timer;
+                }, this.search.options.scanning.delay);
+            } else {
+                this.onMouseMove(e);
+            }
+        });
+        element.addEventListener('mouseleave', (e) => {
+            this.onMouseLeave(e);
+        });
+    }
+
+    static processParseResultForDisplay(result) {
+        return result.map((term) => {
+            return term.filter(part => part.text.trim()).map((part) => {
+                return {
+                    text: Array.from(part.text),
+                    reading: part.reading,
+                    raw: !part.reading || !part.reading.trim(),
+                };
+            });
+        });
+    }
+}
diff --git a/ext/bg/js/search.js b/ext/bg/js/search.js
index ec5a5972..b4731e6a 100644
--- a/ext/bg/js/search.js
+++ b/ext/bg/js/search.js
@@ -32,6 +32,8 @@ class DisplaySearch extends Display {
             url: window.location.href
         };
 
+        this.queryParser = new QueryParser(this);
+
         this.search = document.querySelector('#search');
         this.query = document.querySelector('#query');
         this.intro = document.querySelector('#intro');
@@ -72,11 +74,11 @@ class DisplaySearch extends Display {
                         const query = DisplaySearch.getSearchQueryFromLocation(window.location.href) || '';
                         if (e.target.checked) {
                             window.wanakana.bind(this.query);
-                            this.query.value = window.wanakana.toKana(query);
+                            this.setQuery(window.wanakana.toKana(query));
                             apiOptionsSet({general: {enableWanakana: true}}, this.getOptionsContext());
                         } else {
                             window.wanakana.unbind(this.query);
-                            this.query.value = query;
+                            this.setQuery(query);
                             apiOptionsSet({general: {enableWanakana: false}}, this.getOptionsContext());
                         }
                         this.onSearchQueryUpdated(this.query.value, false);
@@ -86,9 +88,9 @@ class DisplaySearch extends Display {
                 const query = DisplaySearch.getSearchQueryFromLocation(window.location.href);
                 if (query !== null) {
                     if (this.isWanakanaEnabled()) {
-                        this.query.value = window.wanakana.toKana(query);
+                        this.setQuery(window.wanakana.toKana(query));
                     } else {
-                        this.query.value = query;
+                        this.setQuery(query);
                     }
                     this.onSearchQueryUpdated(this.query.value, false);
                 }
@@ -159,6 +161,7 @@ class DisplaySearch extends Display {
         e.preventDefault();
 
         const query = this.query.value;
+        this.queryParser.setText(query);
         const queryString = query.length > 0 ? `?query=${encodeURIComponent(query)}` : '';
         window.history.pushState(null, '', `${window.location.pathname}${queryString}`);
         this.onSearchQueryUpdated(query, true);
@@ -168,9 +171,9 @@ class DisplaySearch extends Display {
         const query = DisplaySearch.getSearchQueryFromLocation(window.location.href) || '';
         if (this.query !== null) {
             if (this.isWanakanaEnabled()) {
-                this.query.value = window.wanakana.toKana(query);
+                this.setQuery(window.wanakana.toKana(query));
             } else {
-                this.query.value = query;
+                this.setQuery(query);
             }
         }
 
@@ -258,9 +261,9 @@ class DisplaySearch extends Display {
             }
             if (curText && (curText !== this.clipboardPrevText) && jpIsJapaneseText(curText)) {
                 if (this.isWanakanaEnabled()) {
-                    this.query.value = window.wanakana.toKana(curText);
+                    this.setQuery(window.wanakana.toKana(curText));
                 } else {
-                    this.query.value = curText;
+                    this.setQuery(curText);
                 }
 
                 const queryString = curText.length > 0 ? `?query=${encodeURIComponent(curText)}` : '';
@@ -287,6 +290,11 @@ class DisplaySearch extends Display {
         return this.optionsContext;
     }
 
+    setQuery(query) {
+        this.query.value = query;
+        this.queryParser.setText(query);
+    }
+
     setIntroVisible(visible, animate) {
         if (this.introVisible === visible) {
             return;
diff --git a/ext/bg/js/settings.js b/ext/bg/js/settings.js
index e562c54e..ab267c32 100644
--- a/ext/bg/js/settings.js
+++ b/ext/bg/js/settings.js
@@ -64,6 +64,10 @@ async function formRead(options) {
     options.scanning.modifier = $('#scan-modifier-key').val();
     options.scanning.popupNestingMaxDepth = parseInt($('#popup-nesting-max-depth').val(), 10);
 
+    options.parsing.enableScanningParser = $('#parsing-scan-enable').prop('checked');
+    options.parsing.enableMecabParser = $('#parsing-mecab-enable').prop('checked');
+    options.parsing.readingMode = $('#parsing-reading-mode').val();
+
     const optionsAnkiEnableOld = options.anki.enable;
     options.anki.enable = $('#anki-enable').prop('checked');
     options.anki.tags = utilBackgroundIsolate($('#card-tags').val().split(/[,; ]+/));
@@ -126,6 +130,10 @@ async function formWrite(options) {
     $('#scan-modifier-key').val(options.scanning.modifier);
     $('#popup-nesting-max-depth').val(options.scanning.popupNestingMaxDepth);
 
+    $('#parsing-scan-enable').prop('checked', options.parsing.enableScanningParser);
+    $('#parsing-mecab-enable').prop('checked', options.parsing.enableMecabParser);
+    $('#parsing-reading-mode').val(options.parsing.readingMode);
+
     $('#anki-enable').prop('checked', options.anki.enable);
     $('#card-tags').val(options.anki.tags.join(' '));
     $('#sentence-detection-extent').val(options.anki.sentenceExt);
diff --git a/ext/bg/js/templates.js b/ext/bg/js/templates.js
index 823b9e6f..6e377957 100644
--- a/ext/bg/js/templates.js
+++ b/ext/bg/js/templates.js
@@ -163,6 +163,58 @@ templates['kanji.html'] = template({"1":function(container,depth0,helpers,partia
   }
 
 ,"useDecorators":true,"usePartial":true,"useData":true,"useDepths":true});
+templates['query-parser.html'] = template({"1":function(container,depth0,helpers,partials,data) {
+    var stack1, alias1=depth0 != null ? depth0 : (container.nullContext || {});
+
+  return ((stack1 = helpers["if"].call(alias1,(depth0 != null ? depth0.preview : depth0),{"name":"if","hash":{},"fn":container.program(2, data, 0),"inverse":container.program(4, data, 0),"data":data})) != null ? stack1 : "")
+    + ((stack1 = helpers.each.call(alias1,depth0,{"name":"each","hash":{},"fn":container.program(6, data, 0),"inverse":container.noop,"data":data})) != null ? stack1 : "")
+    + "</span>";
+},"2":function(container,depth0,helpers,partials,data) {
+    return "<span class=\"query-parser-term-preview\">";
+},"4":function(container,depth0,helpers,partials,data) {
+    return "<span class=\"query-parser-term\">";
+},"6":function(container,depth0,helpers,partials,data) {
+    var stack1;
+
+  return ((stack1 = container.invokePartial(partials.part,depth0,{"name":"part","data":data,"helpers":helpers,"partials":partials,"decorators":container.decorators})) != null ? stack1 : "");
+},"8":function(container,depth0,helpers,partials,data) {
+    var stack1;
+
+  return ((stack1 = helpers["if"].call(depth0 != null ? depth0 : (container.nullContext || {}),(depth0 != null ? depth0.raw : depth0),{"name":"if","hash":{},"fn":container.program(9, data, 0),"inverse":container.program(12, data, 0),"data":data})) != null ? stack1 : "");
+},"9":function(container,depth0,helpers,partials,data) {
+    var stack1;
+
+  return ((stack1 = helpers.each.call(depth0 != null ? depth0 : (container.nullContext || {}),(depth0 != null ? depth0.text : depth0),{"name":"each","hash":{},"fn":container.program(10, data, 0),"inverse":container.noop,"data":data})) != null ? stack1 : "");
+},"10":function(container,depth0,helpers,partials,data) {
+    return "<span class=\"query-parser-char\">"
+    + container.escapeExpression(container.lambda(depth0, depth0))
+    + "</span>";
+},"12":function(container,depth0,helpers,partials,data) {
+    var stack1, helper, alias1=depth0 != null ? depth0 : (container.nullContext || {});
+
+  return "<ruby>"
+    + ((stack1 = helpers.each.call(alias1,(depth0 != null ? depth0.text : depth0),{"name":"each","hash":{},"fn":container.program(10, data, 0),"inverse":container.noop,"data":data})) != null ? stack1 : "")
+    + "<rt>"
+    + container.escapeExpression(((helper = (helper = helpers.reading || (depth0 != null ? depth0.reading : depth0)) != null ? helper : helpers.helperMissing),(typeof helper === "function" ? helper.call(alias1,{"name":"reading","hash":{},"data":data}) : helper)))
+    + "</rt></ruby>";
+},"14":function(container,depth0,helpers,partials,data,blockParams,depths) {
+    var stack1;
+
+  return ((stack1 = container.invokePartial(partials.term,depth0,{"name":"term","hash":{"preview":(depths[1] != null ? depths[1].preview : depths[1])},"data":data,"helpers":helpers,"partials":partials,"decorators":container.decorators})) != null ? stack1 : "");
+},"compiler":[7,">= 4.0.0"],"main":function(container,depth0,helpers,partials,data,blockParams,depths) {
+    var stack1;
+
+  return ((stack1 = helpers.each.call(depth0 != null ? depth0 : (container.nullContext || {}),(depth0 != null ? depth0.terms : depth0),{"name":"each","hash":{},"fn":container.program(14, data, 0, blockParams, depths),"inverse":container.noop,"data":data})) != null ? stack1 : "");
+},"main_d":  function(fn, props, container, depth0, data, blockParams, depths) {
+
+  var decorators = container.decorators;
+
+  fn = decorators.inline(fn,props,container,{"name":"inline","hash":{},"fn":container.program(1, data, 0, blockParams, depths),"inverse":container.noop,"args":["term"],"data":data}) || fn;
+  fn = decorators.inline(fn,props,container,{"name":"inline","hash":{},"fn":container.program(8, data, 0, blockParams, depths),"inverse":container.noop,"args":["part"],"data":data}) || fn;
+  return fn;
+  }
+
+,"useDecorators":true,"usePartial":true,"useData":true,"useDepths":true});
 templates['terms.html'] = template({"1":function(container,depth0,helpers,partials,data) {
     var stack1, helper, options, alias1=depth0 != null ? depth0 : (container.nullContext || {}), buffer = 
   "<div class=\"dict-";
diff --git a/ext/bg/search.html b/ext/bg/search.html
index 54c5fb6c..e819ebe6 100644
--- a/ext/bg/search.html
+++ b/ext/bg/search.html
@@ -47,6 +47,13 @@
                 <img src="/mixed/img/spinner.gif">
             </div>
 
+            <div class="scan-disable">
+                <div id="query-parser-select" class="input-group"></div>
+                <div id="query-parser"></div>
+            </div>
+
+            <hr>
+
             <div id="content"></div>
         </div>
 
@@ -67,6 +74,7 @@
         <script src="/mixed/js/japanese.js"></script>
         <script src="/mixed/js/scroll.js"></script>
 
+        <script src="/bg/js/search-query-parser.js"></script>
         <script src="/bg/js/search.js"></script>
         <script src="/bg/js/search-frontend.js"></script>
     </body>
diff --git a/ext/bg/settings.html b/ext/bg/settings.html
index f95e76a1..262386e9 100644
--- a/ext/bg/settings.html
+++ b/ext/bg/settings.html
@@ -410,6 +410,44 @@
                 </div>
             </div>
 
+            <div id="text-parsing">
+                <h3>Text Parsing Options</h3>
+
+                <p class="help-block">
+                    Yomichan can attempt to parse entire sentences or longer text blocks on the search page,
+                    adding furigana above words and a small space between words.
+                </p>
+
+                <p class="help-block">
+                    Two types of parsers are supported. The first one, enabled by default, works using the built-in
+                    scanning functionality by automatically advancing in the sentence after a matching word.
+                </p>
+
+                <p class="help-block">
+                    The second type is an external program called <a href="https://en.wikipedia.org/wiki/MeCab" target="_blank" rel="noopener">MeCab</a>
+                    that uses its own dictionaries and a special parsing algorithm. To get it working, you must first
+                    install it and <a href="https://github.com/siikamiika/yomichan-mecab-installer" target="_blank" rel="noopener">a native messaging component</a>
+                    that acts as a bridge between the program and Yomichan.
+                </p>
+
+                <div class="checkbox">
+                    <label><input type="checkbox" id="parsing-scan-enable"> Enable text parsing using installed dictionaries</label>
+                </div>
+
+                <div class="checkbox">
+                    <label><input type="checkbox" id="parsing-mecab-enable"> Enable text parsing using MeCab</label>
+                </div>
+
+                <div class="form-group">
+                    <label for="parsing-reading-mode">Reading mode</label>
+                    <select class="form-control" id="parsing-reading-mode">
+                        <option value="hiragana">ひらがな</option>
+                        <option value="katakana">カタカナ</option>
+                        <option value="romaji">Romaji</option>
+                    </select>
+                </div>
+            </div>
+
             <div class="ignore-form-changes">
                 <div>
                     <img src="/mixed/img/spinner.gif" class="pull-right" id="dict-spinner" alt>
diff --git a/ext/fg/js/api.js b/ext/fg/js/api.js
index 945ba076..92330d9c 100644
--- a/ext/fg/js/api.js
+++ b/ext/fg/js/api.js
@@ -29,6 +29,14 @@ function apiTermsFind(text, details, optionsContext) {
     return utilInvoke('termsFind', {text, details, optionsContext});
 }
 
+function apiTextParse(text, optionsContext) {
+    return utilInvoke('textParse', {text, optionsContext});
+}
+
+function apiTextParseMecab(text, optionsContext) {
+    return utilInvoke('textParseMecab', {text, optionsContext});
+}
+
 function apiKanjiFind(text, optionsContext) {
     return utilInvoke('kanjiFind', {text, optionsContext});
 }
diff --git a/ext/manifest.json b/ext/manifest.json
index fabceafd..4d75cd54 100644
--- a/ext/manifest.json
+++ b/ext/manifest.json
@@ -42,7 +42,8 @@
         "<all_urls>",
         "storage",
         "clipboardWrite",
-        "unlimitedStorage"
+        "unlimitedStorage",
+        "nativeMessaging"
     ],
     "optional_permissions": [
         "clipboardRead"
diff --git a/ext/mixed/css/display.css b/ext/mixed/css/display.css
index 7ee6f5ac..ba2fadb7 100644
--- a/ext/mixed/css/display.css
+++ b/ext/mixed/css/display.css
@@ -88,6 +88,19 @@ ol, ul {
     user-select: none;
 }
 
+#query-parser {
+    margin-top: 10px;
+    font-size: 24px;
+}
+
+.query-parser-term {
+    margin-right: 5px;
+}
+
+html:root[data-yomichan-page=search] body {
+    overflow-y: scroll; /* always show scroll bar to avoid scanning problems */
+}
+
 
 /*
  * Entries
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 8ad3ee1b..4c698ecf 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -98,17 +98,62 @@ class Display {
         }
     }
 
-    async onTermLookup(e) {
+    async onTermLookup(e, {disableScroll, selectText, disableHistory}={}) {
+        const termLookupResults = await this.termLookup(e);
+        if (!termLookupResults) {
+            return false;
+        }
+
+        try {
+            const {textSource, definitions} = termLookupResults;
+
+            const scannedElement = e.target;
+            const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
+
+            if (!disableScroll) {
+                this.windowScroll.toY(0);
+            }
+            let context;
+            if (disableHistory) {
+                const {url, source} = this.context || {};
+                context = {sentence, url, source, disableScroll};
+            } else {
+                context = {
+                    disableScroll,
+                    source: {
+                        definitions: this.definitions,
+                        index: this.entryIndexFind(scannedElement),
+                        scroll: this.windowScroll.y
+                    }
+                };
+
+                if (this.context) {
+                    context.sentence = sentence;
+                    context.url = this.context.url;
+                    context.source.source = this.context.source;
+                }
+            }
+
+            this.setContentTerms(definitions, context);
+
+            if (selectText) {
+                textSource.select();
+            }
+        } catch (error) {
+            this.onError(error);
+        }
+    }
+
+    async termLookup(e) {
         try {
             e.preventDefault();
 
-            const clickedElement = e.target;
             const textSource = docRangeFromPoint(e.clientX, e.clientY, this.options);
             if (textSource === null) {
                 return false;
             }
 
-            let definitions, length, sentence;
+            let definitions, length;
             try {
                 textSource.setEndOffset(this.options.scanning.length);
 
@@ -118,28 +163,11 @@ class Display {
                 }
 
                 textSource.setEndOffset(length);
-
-                sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
             } finally {
                 textSource.cleanup();
             }
 
-            this.windowScroll.toY(0);
-            const context = {
-                source: {
-                    definitions: this.definitions,
-                    index: this.entryIndexFind(clickedElement),
-                    scroll: this.windowScroll.y
-                }
-            };
-
-            if (this.context) {
-                context.sentence = sentence;
-                context.url = this.context.url;
-                context.source.source = this.context.source;
-            }
-
-            this.setContentTerms(definitions, context);
+            return {textSource, definitions};
         } catch (error) {
             this.onError(error);
         }
@@ -336,8 +364,10 @@ class Display {
 
             const content = await apiTemplateRender('terms.html', params);
             this.container.innerHTML = content;
-            const {index, scroll} = context || {};
-            this.entryScrollIntoView(index || 0, scroll);
+            const {index, scroll, disableScroll} = context || {};
+            if (!disableScroll) {
+                this.entryScrollIntoView(index || 0, scroll);
+            }
 
             if (options.audio.enabled && options.audio.autoPlay) {
                 this.autoPlayAudio();
diff --git a/ext/mixed/js/japanese.js b/ext/mixed/js/japanese.js
index d24f56a6..a7cd0452 100644
--- a/ext/mixed/js/japanese.js
+++ b/ext/mixed/js/japanese.js
@@ -48,6 +48,43 @@ function jpKatakanaToHiragana(text) {
     return result;
 }
 
+function jpHiraganaToKatakana(text) {
+    let result = '';
+    for (const c of text) {
+        if (wanakana.isHiragana(c)) {
+            result += wanakana.toKatakana(c);
+        } else {
+            result += c;
+        }
+    }
+
+    return result;
+}
+
+function jpToRomaji(text) {
+    return wanakana.toRomaji(text);
+}
+
+function jpConvertReading(expressionFragment, readingFragment, readingMode) {
+    switch (readingMode) {
+        case 'hiragana':
+            return jpKatakanaToHiragana(readingFragment || '');
+        case 'katakana':
+            return jpHiraganaToKatakana(readingFragment || '');
+        case 'romaji':
+            if (readingFragment) {
+                return jpToRomaji(readingFragment);
+            } else {
+                if (jpIsKana(expressionFragment)) {
+                    return jpToRomaji(expressionFragment);
+                }
+            }
+            return readingFragment;
+        default:
+            return readingFragment;
+    }
+}
+
 function jpDistributeFurigana(expression, reading) {
     const fallback = [{furigana: reading, text: expression}];
     if (!reading) {
@@ -61,12 +98,11 @@ function jpDistributeFurigana(expression, reading) {
 
         const group = groups[0];
         if (group.mode === 'kana') {
-            if (reading.startsWith(group.text)) {
-                const readingUsed = reading.substring(0, group.text.length);
+            if (jpKatakanaToHiragana(reading).startsWith(jpKatakanaToHiragana(group.text))) {
                 const readingLeft = reading.substring(group.text.length);
                 const segs = segmentize(readingLeft, groups.splice(1));
                 if (segs) {
-                    return [{text: readingUsed}].concat(segs);
+                    return [{text: group.text}].concat(segs);
                 }
             }
         } else {
@@ -95,3 +131,30 @@ function jpDistributeFurigana(expression, reading) {
 
     return segmentize(reading, groups) || fallback;
 }
+
+function jpDistributeFuriganaInflected(expression, reading, source) {
+    const output = [];
+
+    let stemLength = 0;
+    const shortest = Math.min(source.length, expression.length);
+    const sourceHiragana = jpKatakanaToHiragana(source);
+    const expressionHiragana = jpKatakanaToHiragana(expression);
+    while (stemLength < shortest && sourceHiragana[stemLength] === expressionHiragana[stemLength]) {
+        ++stemLength;
+    }
+    const offset = source.length - stemLength;
+
+    const stemExpression = source.slice(0, source.length - offset);
+    const stemReading = reading.slice(
+        0, offset === 0 ? reading.length : reading.length - expression.length + stemLength
+    );
+    for (const segment of jpDistributeFurigana(stemExpression, stemReading)) {
+        output.push(segment);
+    }
+
+    if (stemLength !== source.length) {
+        output.push({text: source.slice(stemLength)});
+    }
+
+    return output;
+}
diff --git a/tmpl/query-parser.html b/tmpl/query-parser.html
new file mode 100644
index 00000000..db98b5ff
--- /dev/null
+++ b/tmpl/query-parser.html
@@ -0,0 +1,27 @@
+{{~#*inline "term"~}}
+{{~#if preview~}}
+<span class="query-parser-term-preview">
+{{~else~}}
+<span class="query-parser-term">
+{{~/if~}}
+{{~#each this~}}
+{{> part }}
+{{~/each~}}
+</span>
+{{~/inline~}}
+
+{{~#*inline "part"~}}
+{{~#if raw~}}
+{{~#each text~}}
+<span class="query-parser-char">{{this}}</span>
+{{~/each~}}
+{{~else~}}
+<ruby>{{~#each text~}}
+<span class="query-parser-char">{{this}}</span>
+{{~/each~}}<rt>{{reading}}</rt></ruby>
+{{~/if~}}
+{{~/inline~}}
+
+{{~#each terms~}}
+{{> term preview=../preview }}
+{{~/each~}}