Hide/show autocomplete based on selection state

src/autocomplete/AutocompleteProvider.js

@@ -1,4 +1,41 @@
+import Q from 'q';
+
 export default class AutocompleteProvider {
+    constructor(commandRegex?: RegExp, fuseOpts?: any) {
+        if(commandRegex) {
+            if(!commandRegex.global) {
+                throw new Error('commandRegex must have global flag set');
+            }
+            this.commandRegex = commandRegex;
+        }
+    }
+
+    /**
+     * Of the matched commands in the query, returns the first that contains or is contained by the selection, or null.
+     */
+    getCurrentCommand(query: string, selection: {start: number, end: number}): ?Array<string> {
+        if(this.commandRegex == null)
+            return null;
+
+        let match = null;
+        while((match = this.commandRegex.exec(query)) != null) {
+            let matchStart = match.index,
+                matchEnd = matchStart + match[0].length;
+
+            console.log(match);
+            
+            if(selection.start <= matchEnd && selection.end >= matchStart) {
+                return match;
+            }
+        }
+        this.commandRegex.lastIndex = 0;
+        return null;
+    }
+
+    getCompletions(query: String, selection: {start: number, end: number}) {
+        return Q.when([]);
+    }
+
     getName(): string {
         return 'Default Provider';
     }