Navigation :

Envision Gallery

This gallery contains sample Envision scripts and sample datasets.

VS Code extension for Envision

While Envision is usually intended to be authored via the web-based integrated development environment provided by Lokad, there is also a VS Code extension for Envision. This extension provides code coloring and compilation support (via the public compilation endpoint).

Pretty-print Envision scripts

To pretty-print Envision scripts in a web page, you should:

  1. include the JavaScript file https://docs.lokad.com/js/envision.min.js
  2. use <code class=language-envision data-lang=envision> blocks to introduce you scripts.
  3. call globalThis.highlightElementsWithClass('language-envision')

The following minimal HTML page illustrates the process:

<!DOCTYPE html>
<html lang="en">
    <head>
        <script src=https://docs.lokad.com/js/envision.min.js></script>
    </head>
    <body>
        <code class=language-envision data-lang=envision>
montecarlo 1000 with // approximate π value
x = random.uniform(-1, 1)
y = random.uniform(-1, 1)
inCircle = x^2 + y^2 < 1
sample approxPi = avg(if inCircle then 4 else 0)
show scalar "π approximation" with approxPi // 3.22
        </code>
        <script>
            syntax.highlightElementsWithClass('language-envision');
        </script>
    </body>
</html>

Lokad grants you the right to host a local copy Envision.min.js.

Public compilation endpoint for Envision

This endpoint takes an Envision script as input, and returns the compilation errors, if any.

The payload to be sent in the HTTP request body is a JSON object with the following structure:

{
  "Script": "show label \"Welcome to Envision!\" a1b1 tomato"
}

Envision offers some degree of code reuse via modules. If the original script makes use of one or several modules, it is possible to pass them alongside the script.

{
  "Script": "import \"\/path\/to\/module\/one\" as M1\nimport \"path\/to\/module\/two\" as M2\n\nshow label M2.greetings(\"Jane Doe\") a1b1 {textColor: #(M1.green)}",
  "Modules": {
        "path/to/module/one": "export const green = rgb(0.0, 0.5, 0.0)",
        "path/to/module/two": "export def const pure greetings(name : text) with\n  return\"Hello \\{name}\"",
    }
}

The response properties include IsCompOk (Boolean) and CompMessages (array). If the compilation fails, then the IsCompOk property will be false, and the CompMessages array will contain one or more objects, each representing an error or a warning message, as illustrated by:

{
  "IsCompOk": false,
  "CompMessages": [
    {
      "Text": "Compilation error message",
      "Line": 10,
      "Start": 5,
      "Length": 15,
      "Severity": "Error"
    }
  ]
}
User Contributed Notes
0 notes + add a note

© Lokad 2014 - 2025