Code completion

Invoke basic completion

1. Start typing a name. By default, AppCode displays the code completion popup automatically as you type.

   If automatic completion is disabled, press ⌃ Space or choose Code | Code Completion | Basic from the main menu.

2. To narrow down the suggestions list, type any part of the expected name or keyword (even characters from somewhere in the middle are accepted) or invoke code completion after a dot separator. AppCode shows the suggestions that include the typed characters in any positions.

   In case of CamelCase or snake_case names, you can type the initial letters only, and AppCode will show appropriate suggestions.

   

3. Accept an appropriate suggestion pressing ⏎. You can also do the following:

   • Double-click a list item to insert it to the left of the caret.

   • Press ⇥ to replace the characters to the right from the caret.

   • Use ⌃ ⇧ ⏎ to make the current code construct syntactically correct (balance parentheses, add missing braces and semicolons, and so on).

Invoke type-matching completion

1. Start typing. By default, AppCode displays the code completion popup automatically as you type. If automatic completion is disabled, press ⌃ ⇧ Space or choose Code | Code Completion | Type-Matching from the main menu.

2. Press ⌃ ⇧ Space or choose Code | Code Completion | Type-Matching from the main menu.

   

3. If necessary, press ⌃ ⇧ Space once again. AppCode will look up values of the expected type which can be retrieved through a chained method call.

Expand a string at caret to an existing word

1. Type the initial string and do one of the following:

   • Press ⌥ / or choose Code | Code Completion | Cyclic Expand Word to search for matching words before the caret.

   • Press ⌥ ⇧ / or choose Code | Code Completion | Cyclic Expand Word (Backward) to search for matching words after the caret and in other open files.

   The first suggested value appears, and the prototype is highlighted in the source code.

2. Accept the suggestion, or hold the Alt key and keep pressing / until the desired word is found.

Enable and configure postfix completion

• Go to Settings / Preferences | Editor | General | Postfix Completion and select the Enable postfix completion checkbox.

• Select ⇥, Space, or ⏎ to be used for expanding postfix templates.

• Enable/disable a particular postfix template for the selected language.

Transform a statement with a postfix

• Type an expression and then type a postfix after a dot, for example, .if:

  function m(arg) { arg.if }

  The initial expression gets wrapped with an if statement:

  function m(arg) { if (arg) { } }

Create custom postfix templates

1. Press ⌃ ⌥ S to open the IDE settings and select Editor | General | Postfix Completion.

2. Click the Add button () on the toolbar.

3. Specify Key that is a combination of symbols that will invoke the template.

4. Select which expression types the new template will be applicable to, and type the target expression in the following format: $EXPR$ <target_expression>, for example, $EXPR$ =!null.

Configure completion options

1. Press ⌃ ⌥ S to open the IDE settings and select Editor | General | Code Completion.

2. • To automatically display the suggestions list, select the Show suggestions as you type checkbox. If the checkbox is cleared, you have to call code completion explicitly by pressing ⌃ Space for basic completion or ⌃ ⇧ Space for type-matching completion.

     You can also choose to automatically insert suggestions when there's just one option: select the completion type under Automatically insert single suggestions for.

   • To sort suggestions in the alphabetical order, instead of sorting them by relevance, select the Sort suggestions alphabetically checkbox.

     You can also toggle these modes by clicking or respectively in the lower-right corner of the suggestions list.

   • If you want word case not to be taken into account (like in Xcode, for example), uncheck Match case.

   • If you want the documentation popup to be displayed automatically for each item in the suggestions list as you scroll it, select the Show documentation popup in option. In the field to the right, specify the delay (in milliseconds), after which the popup should appear.

View reference

• You can use the Definitions by pressing ⌃ ⇧ I when you select an entry in the suggestions list:

  

• You can use the Quick Information view by pressing ⌃ Q when you select an entry in the suggestions list:

  

Use method parameters placeholders

When you choose a method call from the suggestions list, the IDE inserts placeholders for argument values that include a name and a type of a parameter:

Upon completing selection from the suggestion list, you can replace the placeholders with the actual arguments values.

Use machine-learning-assisted code completion

For Swift, JavaScript, and TypeScript, you can utilize machine learning models to rank most suitable items higher in the suggestions list.

The suggestions list will change to look like the following with the arrows showing you how it was re-ordered based on ML, and the most suitable suggestion on the top marked with the star:

To do so, press ⌃ ⌥ S to open the IDE settings and select Editor | General | Code Completion, and then enable the Sort completion suggestions based on machine learning option under Machine Learning-Assisted Completion.