Add snippet support for LaTeX and custom macro completer.

The snippets are copied from the snippets for TeX.
The current keywordCompleter for LaTeX is unused because the highlight rules
do not give a list of keywords, but color every LaTeX macro, so the completer
cannot use the rules to provide completion. This macro completer is inspired
by the text completer, but autocomplete only macros (the current text completer
do not consider \ to be a part of a word).

The interface of Completer is changed so that the keywordCompleter can forward
the triggerCharacters and identifiersRegexps of `session.$mode.completer`.

Author: JeanCASPAR

ace-internal.d.ts

@@ -976,7 +976,7 @@ export namespace Ace {
 
     interface Completer {
         /** Regular expressions defining valid identifier characters for completion triggers */
-        identifierRegexps?: Array<RegExp>,
+        identifierRegexps?: Array<RegExp> | ((editor: Editor) => Array<RegExp>),
 
         /** Main completion method that provides suggestions for the given context */
         getCompletions(editor: Editor,
@@ -999,7 +999,7 @@ export namespace Ace {
         /** Unique identifier for this completer */
         id?: string;
         /** Characters that trigger autocompletion when typed */
-        triggerCharacters?: string[];
+        triggerCharacters?: string[] | ((editor: Editor) => string[]);
         /** Whether to hide inline preview text */
         hideInlinePreview?: boolean;
         /** Custom insertion handler for completion items */

ace.d.ts

@@ -783,7 +783,7 @@ declare module "ace-code" {
         type CompleterCallback = (error: any, completions: Completion[]) => void;
         interface Completer {
             /** Regular expressions defining valid identifier characters for completion triggers */
-            identifierRegexps?: Array<RegExp>;
+            identifierRegexps?: Array<RegExp> | ((editor: Editor) => Array<RegExp>);
             /** Main completion method that provides suggestions for the given context */
             getCompletions(editor: Editor, session: EditSession, position: Point, prefix: string, callback: CompleterCallback): void;
             /** Returns documentation tooltip for a completion item */
@@ -797,7 +797,7 @@ declare module "ace-code" {
             /** Unique identifier for this completer */
             id?: string;
             /** Characters that trigger autocompletion when typed */
-            triggerCharacters?: string[];
+            triggerCharacters?: string[] | ((editor: Editor) => string[]);
             /** Whether to hide inline preview text */
             hideInlinePreview?: boolean;
             /** Custom insertion handler for completion items */

src/autocomplete/util.js

@@ -54,10 +54,18 @@ exports.getCompletionPrefix = function (editor) {
     var prefix;
     editor.completers.forEach(function(completer) {
         if (completer.identifierRegexps) {
-            completer.identifierRegexps.forEach(function(identifierRegex) {
-                if (!prefix && identifierRegex)
-                    prefix = this.retrievePrecedingIdentifier(line, pos.column, identifierRegex);
-            }.bind(this));
+            var identifierRegexps;
+            if (completer.identifierRegexps instanceof Function) {
+                identifierRegexps = completer.identifierRegexps(editor);
+            } else {
+                identifierRegexps = completer.identifierRegexps;
+            }
+            if (identifierRegexps && Array.isArray(identifierRegexps)) {
+                completer.identifierRegexps.forEach(function(identifierRegex) {
+                    if (!prefix && identifierRegex)
+                        prefix = this.retrievePrecedingIdentifier(line, pos.column, identifierRegex);
+                }.bind(this));
+            }
         }
     }.bind(this));
     return prefix || this.retrievePrecedingIdentifier(line, pos.column);
@@ -73,8 +81,17 @@ exports.triggerAutocomplete = function (editor, previousChar) {
         ? editor.session.getPrecedingCharacter()
         : previousChar;
     return editor.completers.some((completer) => {
-        if (completer.triggerCharacters && Array.isArray(completer.triggerCharacters)) {
-            return completer.triggerCharacters.includes(previousChar);
+        if (completer.triggerCharacters) {
+            var triggerCharacters;
+            if (completer.triggerCharacters instanceof Function) {
+                triggerCharacters = completer.triggerCharacters(editor);
+            } else {
+                triggerCharacters = completer.triggerCharacters;
+            }
+
+            if (triggerCharacters && Array.isArray(triggerCharacters)) {
+                return triggerCharacters.includes(previousChar);
+            }
         }
     });
 };

src/ext/language_tools.js

@@ -37,6 +37,16 @@ var MarkerGroup = require("../marker_group").MarkerGroup;
 var textCompleter = require("../autocomplete/text_completer");
 /**@type {import("../../ace-internal").Ace.Completer}*/
 var keyWordCompleter = {
+    identifierRegexps(editor) {
+        var completer = editor.session.$mode.completer;
+        if (completer) {
+            if (completer.identifierRegexps instanceof Function) {
+                return completer.identifierRegexps(editor);
+            } else {
+                return completer.identifierRegexps;
+            }
+        }
+    },
     getCompletions: function(editor, session, pos, prefix, callback) {
         if (session.$mode.completer) {
             return session.$mode.completer.getCompletions(editor, session, pos, prefix, callback);
@@ -49,7 +59,17 @@ var keyWordCompleter = {
         });
         callback(null, completions);
     },
-    id: "keywordCompleter"
+    id: "keywordCompleter",
+    triggerCharacters(editor) {
+        var completer = editor.session.$mode.completer;
+        if (completer) {
+            if (completer.triggerCharacters instanceof Function) {
+                return completer.triggerCharacters(editor);
+            } else {
+                return completer.triggerCharacters;
+            }
+        }
+    }
 };
 
 var transformSnippetTooltip = function(str) {

src/mode/latex.js

@@ -19,6 +19,8 @@ oop.inherits(Mode, TextMode);
     this.lineCommentStart = "%";
 
     this.$id = "ace/mode/latex";
+
+    this.snippetFileId = "ace/snippets/latex";
 
     this.getMatching = function(session, row, column) {
         if (row == undefined)
@@ -35,6 +37,50 @@ oop.inherits(Mode, TextMode);
             return this.foldingRules.latexBlock(session, row, column, true);
         }
     };
+
+    function wordDistances(doc, pos) {
+        var macroName = /\\[a-zA-Z0-9]+/g;
+
+        var textBefore = doc.getTextRange(Range.fromPoints({
+            row: 0,
+            column: 0
+        }, pos));
+        var prefixPos = [...textBefore.matchAll(macroName)].length - 1;
+
+        var words = [...doc.getValue().matchAll(macroName)];
+        var wordScores = Object.create(null);
+
+        var currentWord = words[prefixPos];
+
+        words.forEach(function (word, idx) {
+            if (!word || word === currentWord) return;
+
+            var distance = Math.abs(prefixPos - idx);
+            var score = words.length - distance;
+            wordScores[word] = Math.max(score, wordScores[word] ?? 0);
+        });
+        return wordScores;
+    }
+
+    this.completer = {
+        identifierRegexps: [/[\\a-zA-Z0-0]/g],
+        getCompletions: (editor, session, pos, prefix, callback) => {
+            var wordScores = wordDistances(session, pos);
+            var wordList = Object.keys(wordScores);
+            callback(null, wordList.map(function (word) {
+                return {
+                    caption: word,
+                    value: word,
+                    score: wordScores[word],
+                    meta: "macro",
+                    completer: this,
+                    completerId: this.id,
+                };
+            }, this));
+        },
+        triggerCharacters: ["\\"],
+        id: "latexMacroCompleter",
+    };
 }).call(Mode.prototype);
 
 exports.Mode = Mode;

src/snippets/latex.js

@@ -0,0 +1,4 @@
+"use strict";
+
+exports.snippetText = require("./latex.snippets");
+exports.scope = "latex";

src/snippets/latex.snippets.js

@@ -0,0 +1 @@
+module.exports = require("./tex.snippets");