Implement q/ and q? (VSCodeVim#3956)

These show your search history via a QuickPick, allowing you to search through and re-do these.
Also implemented an alias for these, which is `<C-f>` while typing a search.
Refs VSCodeVim#3949

src/actions/commands/actions.ts

@@ -36,6 +36,7 @@ import {
   ReportFileInfo,
   ReportSearch,
 } from '../../util/statusBarTextUtils';
+import { globalState } from '../../state/globalState';
 
 export class DocumentContentChangeAction extends BaseAction {
   contentChanges: {
@@ -884,7 +885,7 @@ class CommandReplaceInReplaceMode extends BaseCommand {
 @RegisterAction
 class CommandInsertInSearchMode extends BaseCommand {
   modes = [ModeName.SearchInProgressMode];
-  keys = [['<character>'], ['<up>'], ['<down>'], ['<C-h>']];
+  keys = [['<character>'], ['<up>'], ['<down>'], ['<C-h>'], ['<C-f>']];
   isJump = true;
 
   runsOnceForEveryCursor() {
@@ -909,6 +910,11 @@ class CommandInsertInSearchMode extends BaseCommand {
         searchState.searchString.slice(0, vimState.statusBarCursorCharacterPos - 1) +
         searchState.searchString.slice(vimState.statusBarCursorCharacterPos);
       vimState.statusBarCursorCharacterPos = Math.max(vimState.statusBarCursorCharacterPos - 1, 0);
+    } else if (key === '<C-f>') {
+      return new CommandShowSearchHistory(vimState.globalState.searchState!.searchDirection).exec(
+        position,
+        vimState
+      );
     } else if (key === '\n') {
       await vimState.setCurrentMode(vimState.globalState.searchState!.previousMode);
 
@@ -2139,6 +2145,37 @@ class CommandShowCommandHistory extends BaseCommand {
   }
 }
 
+@RegisterAction
+class CommandShowSearchHistory extends BaseCommand {
+  modes = [ModeName.Normal, ModeName.Visual, ModeName.VisualLine, ModeName.VisualBlock];
+  keys = [['q', '/'], ['q', '?']];
+
+  private direction = SearchDirection.Forward;
+
+  runsOnceForEveryCursor() {
+    return false;
+  }
+
+  public constructor(direction = SearchDirection.Forward) {
+    super();
+    this.direction = direction;
+  }
+
+  public async exec(position: Position, vimState: VimState): Promise<VimState> {
+    if (vimState.recordedState.commandList.includes('?')) {
+      this.direction = SearchDirection.Backward;
+    }
+    vimState.recordedState.transformations.push({
+      type: 'showSearchHistory',
+      direction: this.direction,
+    });
+
+    await vimState.setCurrentMode(ModeName.Normal);
+
+    return vimState;
+  }
+}
+
 @RegisterAction
 class CommandDot extends BaseCommand {
   modes = [ModeName.Normal];

src/mode/modeHandler.ts

@@ -32,6 +32,8 @@ import {
   isTextTransformation,
   TextTransformations,
 } from './../transformations/transformations';
+import { globalState } from '../state/globalState';
+import { ReportSearch } from '../util/statusBarTextUtils';
 
 export class ModeHandler implements vscode.Disposable {
   private _disposables: vscode.Disposable[] = [];
@@ -909,6 +911,21 @@ export class ModeHandler implements vscode.Disposable {
           }
           break;
 
+        case 'showSearchHistory':
+          const searchState = await globalState.showSearchHistory();
+          if (searchState) {
+            globalState.searchState = searchState;
+            const nextMatch = searchState.getNextSearchMatchPosition(
+              vimState.cursorStartPosition,
+              command.direction
+            );
+
+            vimState.cursorStopPosition = nextMatch.pos;
+            this.updateView(this.vimState);
+            ReportSearch(nextMatch.index, searchState.matchRanges.length, vimState);
+          }
+          break;
+
         case 'dot':
           if (!vimState.globalState.previousFullAction) {
             return vimState; // TODO(bell)

src/state/globalState.ts

@@ -1,3 +1,4 @@
+import * as vscode from 'vscode';
 import { JumpTracker } from '../jumps/jumpTracker';
 import { ModeName } from '../mode/mode';
 import { Position } from '../common/motion/position';
@@ -6,6 +7,7 @@ import { SearchHistory } from '../history/historyFile';
 import { SearchState, SearchDirection } from './searchState';
 import { SubstituteState } from './substituteState';
 import { configuration } from '../configuration/configuration';
+import { VimState } from './vimState';
 
 /**
  * State which stores global state (across editors)
@@ -102,6 +104,29 @@ class GlobalState {
     this.searchStateIndex = this.searchStatePrevious.length - 1;
   }
 
+  public async showSearchHistory(): Promise<SearchState | undefined> {
+    if (!vscode.window.activeTextEditor) {
+      return undefined;
+    }
+
+    const items = this._searchStatePrevious
+      .slice()
+      .reverse()
+      .map(searchState => {
+        return {
+          label: searchState.searchString,
+          searchState: searchState,
+        };
+      });
+
+    const item = await vscode.window.showQuickPick(items, {
+      placeHolder: 'Vim search history',
+      ignoreFocusOut: false,
+    });
+
+    return item ? item.searchState : undefined;
+  }
+
   public get jumpTracker(): JumpTracker {
     return this._jumpTracker;
   }

src/transformations/transformations.ts

@@ -188,6 +188,11 @@ export interface ShowCommandHistory {
   type: 'showCommandHistory';
 }
 
+export interface ShowSearchHistory {
+  type: 'showSearchHistory';
+  direction: number;
+}
+
 /**
  * Represents pressing '.'
  */
@@ -247,6 +252,7 @@ export type Transformation =
   | DeleteTextTransformation
   | MoveCursorTransformation
   | ShowCommandHistory
+  | ShowSearchHistory
   | Dot
   | Macro
   | ContentChangeTransformation