meta.call($function, $args...) invokes a function value with the given arguments and returns the result. Get the function value from meta.get-function() (or meta.module-functions()). Load it with @use "sass:meta".
A remove-where($list, $condition) helper calls meta.call($condition, $element) for each item—for example filtering font names that contain “Helvetica”.
Passing a string function name to call() still works, but Sass deprecates it and will disallow it later. Prefer meta.get-function then meta.call.
Unlike meta.apply (mixins / CSS), meta.call is an expression that yields a result you can assign or emit.
@use "sass:meta";
meta.call($function, $args...); //=> value
@function double($n) {
@return $n * 2;
}
meta.call(meta.get-function("double"), 8px); // 16px
// Deprecated: meta.call("double", 8px);
// Prefer get-function first
// Global alias (legacy): call($function, $args...)
// Prefer meta.call after @use "sass:meta"Pattern: resolve a function value → meta.call with args → use the returned value. For mixins, use meta.apply instead.
Same dynamic idea, different member types:
| Helper | Runs | How you use it |
|---|---|---|
meta.call | Function value | Expression / assignment — returns a value |
meta.apply | Mixin value | @include meta.apply(...) — emits CSS / can take @content |
meta.get-function | — | Builds the function value you call |
String name to call | — | Deprecated; prefer get-function |
Pass a function value into another function (like a condition callback), then invoke it with meta.call inside the loop.
Examples use @use "sass:meta". Open View Compiled CSS for verified output (matches official Sass docs samples where shown).
Resolve with get-function, then invoke with call.
@use "sass:meta";
@function double($n) {
@return $n * 2;
}
.basic {
width: meta.call(meta.get-function("double"), 8px);
}get-function returns a function value.meta.call runs it with 8px.16px.double(8px), but dynamic.remove-whereHigher-order filter: call a condition function for each list item.
@use "sass:list";
@use "sass:meta";
@use "sass:string";
/// Return a copy of $list with all elements for which $condition returns `true`
/// removed.
@function remove-where($list, $condition) {
$new-list: ();
$separator: list.separator($list);
@each $element in $list {
@if not meta.call($condition, $element) {
$new-list: list.append($new-list, $element, $separator: $separator);
}
}
@return $new-list;
}
$fonts: Tahoma, Geneva, "Helvetica Neue", Helvetica, Arial, sans-serif;
.content {
@function contains-helvetica($string) {
@return string.index($string, "Helvetica");
}
font-family: remove-where($fonts, meta.get-function("contains-helvetica"));
}meta.call runs it per font string.get-function can resolve built-ins when no module is passed.
@use "sass:meta";
@use "sass:math";
.builtin {
--abs: #{meta.call(meta.get-function("abs", $module: "math"), -12px)};
}$module: "math" targets the @use namespace.abs becomes a function value.meta.call returns 12px.math.abs(-12px) when the call is not dynamic.Extra args after the function value fill the function signature.
@use "sass:meta";
@function scale($n, $factor) {
@return $n * $factor;
}
.multi {
width: meta.call(meta.get-function("scale"), 10px, 3);
}10px and 3 fill $n and $factor.30px.Use call for return values; use apply for CSS-emitting mixins.
@use "sass:meta";
@function gap($n) {
@return $n * 2;
}
@mixin card($pad) {
.card {
padding: $pad;
}
}
.demo {
margin: meta.call(meta.get-function("gap"), 4px);
@include meta.apply(meta.get-mixin("card"), 1rem);
}meta.call returns 8px for margin.meta.apply includes the mixin.@include meta.call or assign meta.apply.Most call bugs are string names, wrong member type, or mixing up apply.
Use meta.get-function("name"). A bare string is deprecated and will break later.
meta.applymeta.call cannot include a mixin. Use meta.apply with @include.
In the official sample, contains-helvetica is defined inside .content so get-function can see it there.
Pass $module to get-function when the name lives under a @use namespace like math.
Prefer the module form with current Dart Sass.
| API | Status |
|---|---|
meta.call() | Dart Sass via @use "sass:meta" |
Global call() | Legacy; prefer module form |
| String function name | Deprecated; will be removed |
| First argument | Function value (e.g. from meta.get-function) |
Compile with the Dart Sass CLI.
@use "sass:meta".One line: when a function value must be invoked dynamically, call meta.call($function, $args...).
Practical checklist:
1. @use "sass:meta"
2. Resolve a function value (get-function / module-functions)
3. meta.call($fn, $args...)
4. Do not pass a string name (deprecated)
5. Use meta.apply for mixin valuesDetect whether the current mixin received a @content block.
8 people found this page helpful