Repository: typst/typst
File: crates/typst/src/layout/layout.rs (Rust)

Code before:
    dict, elem, func, Content, Context, Func, NativeElement, Packed, StyleChain,
};
use crate::introspection::Locatable;
use crate::layout::{Fragment, LayoutMultiple, Regions, Size};
use crate::syntax::Span;

/// Provides access to the current outer container's (or page's, if none)
/// dimensions (width and height).
///
/// Accepts a function that receives a single parameter, which is a
/// dictionary with keys `width` and `height`, both of type [`length`].
///
/// ```example
/// #let text = lorem(30)
/// #layout(size => [
///   #let (height,) = measure(
///     block(width: size.width, text),
///   )
///   This text is #height high with
///   the current page width: \
///   #text
/// ])
/// ```
///
/// If the `layout` call is placed inside a box with a width of `{800pt}` and a
/// height of `{400pt}`, then the specified function will be given the parameter
/// `{(width: 800pt, height: 400pt)}`. If it is placed directly into the page, it
/// receives the page's dimensions minus its margins. This is mostly useful in
/// combination with [measurement]($measure).
///
/// You can also use this function to resolve [`ratio`] to fixed lengths. This
/// might come in handy if you're building your own layout abstractions.
///
/// ```example
/// #layout(size => {
///   let half = 50% * size.width
///   [Half a page is #half wide.]
/// })
/// ```
///
/// Note that the width or height provided by `layout` will be infinite if the
/// corresponding page dimension is set to `{auto}`.
///
/// Moreover, this function also provides [context]($context) to its argument,
/// so you don't need to use it in combination with the `context` keyword.
#[func]
pub fn layout(
    /// The call span of this function.
    span: Span,
    /// A function to call with the outer container's size. Its return value is
    /// displayed in the document.

Review comment (suggestion):
```suggestion
/// height of `{400pt}`, then the specified function will be given the argument
```
I think generally, `parameter` is the variable at the def-site and `argument` is the actual value at the call-site, so I think this makes more sense.

Code after:
    dict, elem, func, Content, Context, Func, NativeElement, Packed, StyleChain,
};
use crate::introspection::Locatable;
use crate::layout::{Fragment, LayoutMultiple, Regions, Size};
use crate::syntax::Span;

/// Provides access to the current outer container's (or page's, if none)
/// dimensions (width and height).
///
/// Accepts a function that receives a single parameter, which is a dictionary
/// with keys `width` and `height`, both of type [`length`]. The function is
/// provided [context], meaning you don't need to use it in combination with the
/// `context` keyword. This is why [`measure`] can be called in the example
/// below.
///
/// ```example
/// #let text = lorem(30)
/// #layout(size => [
///   #let (height,) = measure(
///     block(width: size.width, text),
///   )
///   This text is #height high with
///   the current page width: \
///   #text
/// ])
/// ```
///
/// If the `layout` call is placed inside a box with a width of `{800pt}` and a
/// height of `{400pt}`, then the specified function will be given the argument
/// `{(width: 800pt, height: 400pt)}`. If it is placed directly into the page, it
/// receives the page's dimensions minus its margins. This is mostly useful in
/// combination with [measurement]($measure).
///
/// You can also use this function to resolve [`ratio`] to fixed lengths. This
/// might come in handy if you're building your own layout abstractions.
///
/// ```example
/// #layout(size => {
///   let half = 50% * size.width
///   [Half a page is #half wide.]
/// })
/// ```
///
/// Note that the width or height provided by `layout` will be infinite if the
/// corresponding page dimension is set to `{auto}`.
#[func]
pub fn layout(
    /// The call span of this function.
    span: Span,
    /// A function to call with the outer container's size. Its return value is
    /// displayed in the document.