GoLand 2023.2 Help

Code completion

This section covers various techniques of context-aware code completion that allow you to speed up your coding process.

Basic completion

Basic code completion helps you complete names of types, interfaces, methods, and keywords within the visibility scope.

When you invoke code completion, GoLand analyses the context and suggests the choices that are reachable from the current caret position (suggestions also include Live templates).

If basic code completion is applied to a part of a field, parameter, or variable declaration, GoLand suggests a list of possible names depending on the item type.

Invoke basic completion

By default, GoLand displays the code completion popup automatically as you type. Alternatively, you can press Control+Space or select Code | Code Completion | Basic from the main menu.

Basic completion

    Code completion for functions

    Invoke completion for functions

    • To view and complete functions that are suitable for a value of the certain type, hold Control and press Space twice.

      For example, you have the t variable of the string type. When you type t., hold Control and press Space twice, you see a list of functions that accept the string type as the first argument.

      Completion for functions

    Type-matching completion

    Invoke type-matching completion

    • Smart type-matching code completion filters the suggestions list and shows only the types applicable to the current context. To invoke type-matching completion, start typing your code and press Control+Shift+Space. Alternatively, select Code | Code Completion | Type-Matching from the main menu. The following animation shows the difference between basic and type-matching completion.

    Statement completion

    You can create syntactically correct code constructs by using statement completion. It inserts the necessary syntax elements (parentheses, braces, and semicolons) and gets you in a position where you can start typing the next statement. To invoke statement completion, start typing a code construct and press Control+Shift+Enter.

    Complete the statement

    Hippie completion

    Hippie completion is a completion engine that analyses your text in the visible scope and generates suggestions from the current context. It helps you complete any word from any of the currently opened files.

    Expand a string at caret to an existing word

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

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

      • Press Alt+Shift+/ 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.

    Postfix code completion

    With post-fix templates, you can transform an already-typed expression to a different one based on a postfix after the dot, the type of the expression, and its context. GoLand includes a set of predefined post-fix completion templates that you can use for other programming languages as well. You can copy, enable, and disable these templates.

    Enable and configure postfix completion

    • In the Settings dialog (Control+Alt+S), open Editor | General | Postfix Completion and select the Enable postfix completion checkbox.

    • Select Tab, Space, or Enter 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:

    func m(b bool) { b.if }

    The initial expression gets wrapped with an if statement:

      You can disable certain postfix completion templates in the Editor | General | Postfix Completion page of the IDE settings Control+Alt+S.

      You can select Tab,Space, or Enter to expand postfix templates.

      You can edit the predefined postfix templates, for example, to replace a long key with a shorter one, or to expand the list of applicable expression types.

      Create custom postfix templates

      1. Press Control+Alt+S to open the IDE settings and then select Editor | General | Postfix Completion.

      2. Click the Add button (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, $EXPR$ != nil.

        Inside your template, you can use two predefined variables, $EXPR$ and $END$:

        • $EXPR$ captures the expression before the dot.

        • $END$ defines the position of the cursor after the template is expanded.

        The Apply to the topmost expression checkbox applies your template to the entire expression ignoring the scope. So you do not need to select the scope for the template each time.

        Create a custom postfix template

      Completion of tags and attributes

      GoLand automatically completes names and values of tags and attributes in HTML/XHTML, XML/XSL, and JSON.

      Completion of tags and attribute names is based on the DTD or Schema the file is associated with. If there is no schema association, GoLand will use the file content (tag and attribute names and their values) to complete your input.

      Support for Go templates

      Machine-learning-assisted code completion

      GoLand allows you to prioritize completion suggestions based on choices that other users made in similar situations.

      The ML completion mechanism doesn't add any new elements but orders the elements retrieved from code. Data is not exposed anywhere; it is collected locally.

      Enable ML completion

      1. Press Control+Alt+S to open the IDE settings and select Editor | General | Code Completion.

      2. Under Machine Learning-Assisted Completion, enable the Sort completion suggestions based on machine learning option, and select the languages for which you want to use ML completion.

        Use machine-learning-assisted code completion

      Enable relevance markers

      1. Press Control+Alt+S to open the IDE settings and select Editor | General | Code Completion.

      2. Enable the following options:

        • Mark position changes in the completion popup: use the Machine Learning ranking Up and Machine Learning ranking Down icons to indicate whether the relevance of a suggestion is increasing or decreasing and therefore the suggestion has moved up or down the suggestion list.

        • Mark the most relevant item in the completion popup: use the ML relevant proposal icon to indicate the most suitable suggestion on the list.

        ML-assisted completion with markers

      Configure code completion settings

      Configure completion options

      1. Press Control+Alt+S to open the IDE settings and then select Editor | General | Code Completion.

        • 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 Control+Space for basic completion or Control+Shift+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 the Sort Alphabetically button or the Sort by Relevance button respectively in the lower-right corner of the suggestions list.

        • 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.

      Completion tips and tricks

      Open completion settings from the completion popup

      You can quickly access code completion settings right from the completion popup.

      • Click the App actions more icon in the completion popup and select Code Completion Settings.

        Opening completion settings

      After that, the Editor | General | Code Completion page of the IDE settings Control+Alt+S opens.

      Narrow down the suggestions list

      • You can narrow down the suggestion list by typing any part of a word (even characters from somewhere in the middle) or invoking code completion after a dot separator . GoLand will show suggestions that include the characters you have entered in any positions.

        This makes the use of wildcards unnecessary:


        In case of CamelCase or snake_case names, type the initial letters only. GoLand automatically recognizes and matches the initial letters.

      Accept a suggestion

      You can accept a suggestion from the list in one of the following ways:

      • Press Enter or double-click a list item to insert it to the left of the caret.

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

      • Use Control+Shift+Enter to make the current code construct syntactically correct (balance parentheses, add missing braces and semicolons, and so on).

      You can also use specific keys to insert the selected completion suggestion: go to the Editor | General | Code Completion page of the IDE settings Control+Alt+S and select the Insert the selected suggestion by pressing space, dot, or other context-dependent keys option. These keys depend on the language, your context, and so on.

      View reference

      • You can use the Quick Definition view by pressing Control+Shift+I when you select an entry in the suggestion list:

        Quick definition
      • You can use the Quick Information view by pressing Control+Q when you select an entry in the suggestion list:

      View code hierarchy

      You can view code hierarchy when you've selected an entry from the suggestion list:

      • Control+H - view type hierarchy

      • Control+Shift+H - view method hierarchy.

      Fill struct fields

      When you create a new struct, you can automatically generate field names for it. This action works for generic structs.

      The IDE ignores auto-generated protocol buffer fields that start with XXX_ when you invoke the Fill all fields intention action. These fields are shown only after you invoke completion for a second time.

      1. Start typing the struct name, select it from the completion list.

      2. Place a caret between braces of a struct.

      3. Press Control+Space. Alternatively, press Alt+Enter.

      4. Select between the following options:

        • Fill all fields: generates values for all the fields that belong to the current struct.

        • Fill all fields recursively: generates values for all the fields that belong to the current struct type and all the pointers to other struct types recursively.

        • Fill fields: displays the Select Fields dialog where you can select the fields that you want to add. Select Recursively to parse fields from all the related structs. Clear the Enforce multiline checkbox to display all fields on a single line. In the Select Fields dialog, press Control and click the fields that you want to add.

      5. Click OK.

        Fill struct fields

      Format date and time

      • The time package uses predefined layouts that you can use in Time.Format and time.Parse. The reference time used in the layouts is the specific time: Mon Jan 2 15:04:05 MST 2006. It means that to define your own format, you need to write down what the reference time would look like formatted your way.

        In GoLand, when you press Control+Space, you will see placeholders for time and data elements from ISO-8601. Code completion also suggests standard time layouts outside of the string literal.

        Support for the time package


      If code completion doesn't work, this may be due to one of the following reasons:

      • The Power Save Mode is on (File | Power Save Mode). Turning it on minimizes power consumption of your laptop by eliminating the background operations, including error highlighting, on-the-fly inspections, and code completion.

      • A file containing types and functions that you want to appear in the completion suggestion list is marked as a plain text file.

      • External libraries that contain functions that you want to appear in the completion suggestions list are not added as dependencies or global libraries.

      • Code completion popup might not appear automatically if it takes too long to gather the completion options. For example, if the computer is busy with another task. In this case, you may still activate the completion popup manually via Ctrl+Space hotkey.

      Last modified: 23 August 2023