/// A list of files converted to data URIs
/// @access private
$data-uris: () !default;

/// Saves a data URI that can be used from the $data-uris map instead of a file reference.
/// @access private
/// @param {String} $name - The name of the resource.
/// @param {String} $content - The data URI of the resource.
/// @require $data-uris
@mixin register-data-uri($name, $content) {
    @if (map-has-key($data-uris, $name)) {
        @warn "Attempt to redefine data URI of file `#{$name}`.";
    }

    $data-uris: map-merge($data-uris, ($name: $content)) !global;
}