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Custom REPL Commands

Calva supports configuration of custom command snippets that you can evaluate in the REPL at will. If your workflow has you repeatedly evaluate a particular piece of code, you can use the setting calva.customREPLCommandSnippets to configure it. Then either bind keyboard shortcuts to them or use the command Run Custom REPL Command to access it. The command will give you a menu with the snippets you have configured.


For some use cases you might be better served by/want to combine these with using the VS Code Extension API, and that of Calva, or any other extension, through Joyride.

The calva.customREPLCommandSnippets is an array of objects with the following fields (required fields in bold):

  • name: The name of the snippet as it will appear in the picker menu
  • snippet: The code that will be evaluated
  • key: A key can be used to reference the snippet from Run Custom REPL Command keyboard shortcut arguments. It will also be used in the quick-pick menu.
  • ns: A namespace to evaluate the command in. If omitted the command will be executed in the namespace of the current editor.
  • repl: Which repl session to use for the evaluation. Either "clj" or "cljs". Omit if you want to use the session of the current editor.

There are also substitutions available, which will take elements from the current state of Calva and splice them in to the text of your command before executing it. They are

  • $line: Current line number in editor
  • $column: Current column number in editor
  • $file: Full name of current file edited
  • $ns: The namespace used for evaluating the command
  • $selection: The currently selected text
  • $current-form: The text of the current form
  • $enclosing-form: The text of the current enclosing form
  • $top-level-form The text of the current top level form
  • $current-fn: The sexpr/form at call position in the current list, e.g. str with (defn foo [] (str "foo" "bar|"))
  • $top-level-defined-symbol: The second symbol of the top level form, e.g. foo with (defn foo [] (str "foo" "bar|"))
  • $head: The text between the start of the current list to the cursor
  • $tail: The text between the cursor and the end of the current list

User and Workspace settings

Settings from your User (global) level and the workspace are merged.

With these User settings:

    "calva.customREPLCommandSnippets": [
            "name": "Call Current Form",
            "key": "c",
            "snippet": "($current-form)"
            "name": "Call Current Top Level Form",
            "key": "t",
            "snippet": "($top-level-form)"
            "name": "CLJ Test Top Level Defined Symbol",
            "repl": "clj",
            "snippet": "(clojure.test/test-var #'$top-level-defined-symbol)"
            "name": "CLJS Test Top Level Defined Symbol",
            "repl": "cljs",
            "snippet": "(cljs.test/test-var #'$top-level-defined-symbol)",
            "key": "tab"

And these Workspace settings:

    "calva.customREPLCommandSnippets": [
            "name": "Remount CLJS App",
            "key": "r",
            "repl": "cljs",
            "ns": "",
            "snippet": "(start)"

Issuing Run Custom REPL Command will then render this VS Code menu:

The default keyboard shortcut for the command is ctrl+alt+space space.

Binding keyboard shortcuts

There are three ways to bind shortcuts to custom commands:

  1. Use a predefined key shortcut. These are predefined as ctrl+alt+space <something>, where <something> is one of:
    • The digits 0 through 9
    • The English letters a through z
    • Arrow keys right, left, up, or down
    • One of tab, backspace, ,, ., or -
  2. Bind calva.runCustomREPLCommand to a shortcut with whatever code you want to evaluate in args key. You have access to the substitution variables here as well.
  3. Bind calva.runCustomREPLCommand to a keyboard shortcut referencing the key of one of your calva.customREPLCommandSnippets. (If not using any of the keys mentioned in 1.)

Custom REPL hover snippets

Calva supports custom snippets that will display their result inside the tooltip. They will only work when connected to a repl, since they eval code in it. This is mostly useful for tooling authors that want to integrate with calva. Be careful with these, since they will be executed anytime Calva displays a tooltip. So they should be fast and probably not have any side effects.

The hover snippets accept the same inputs as the Custom REPL Commands, except for the hotkey:

    "calva.customREPLHoverSnippets": [
            "name": "eval text on hover",
            "repl": "clj",
            "ns": "",
            "snippet": "(str \"$hover-text\")"

With this setting anything the mouse is over will also be shown inside its tooltip. There are now also hover- versions of most substitutions. Those currently only work inside the hover snippets.


Your project can have a .calva/config.edn file that holds a map with calva configs. Currently only :customREPLCommandSnippets and :customREPLHoverSnippets get loaded. These will not get synced through vscode settings sync.

Snippets inside deps

A new experimental feature lets library authors ship snippets inside their jar files. These accept the same options as above but should be placed in "resources/calva.exports/config.edn" inside the jar.

 [{:name "edn test"
   :key "a"
   :snippet "($current-form)"}]
 [{:name "edn hover"
   :snippet "(str \"$hover-tex\")"}
  {:name "edn hover show val"
   :snippet "(str \"### EDN show val\n```clojure\n\" (pr-str (eval (symbol (str \"$ns\" \"/\" \"$hover-top-level-defined-symbol\")))) \"\n```\")"}]}