Returns the first truthy value: a value that isn’t false, null, undefined, or any of the other similar values in JavaScript.
This can be useful in situations like templates to provide a default value for a field that may or may not be present in an input document.
Example: a blog post template uses @or to define a default title.
$ ori blostPost.ori
(post) => `<html>
<head>
<title>${ @or(post/title, "A blog post") }</title>
</head>
<body>
${ post/@text }
</body>
</html>
`
If a blog post defines a title, that title is preferred:
$ cat posts/post1.html
---
title: The First Post
---
Here's the text of my first post.
$ ori blogPost.ori posts/post1.html
<html>
<head>
<title>The First Post</title>
</head>
<body>
Here's the text of my first post.
</body>
</html>
But if a post fails to define a title, the template’s default title is used:
$ cat posts/post2.html
---
# No title
---
Here's the text of my second post.
$ ori blogPost.ori posts/post2.html
<html>
<head>
<title>A blog post</title>
</head>
<body>
Here's the text of my second post.
</body>
</html>