Update standard library functions 🎁

1 files changed, 81 insertions, 0 deletions

diff --git a/src/library/spacing.rs b/src/library/spacing.rs
new file mode 100644
index 00000000..afd26d80
--- /dev/null
+++ b/src/library/spacing.rs
@@ -0,0 +1,81 @@
+use crate::func::prelude::*;
+
+/// `line.break`, `n`: Ends the current line.
+#[derive(Debug, PartialEq)]
+pub struct LineBreak;
+
+function! {
+    data: LineBreak,
+    parse: plain,
+    layout(_, _) { Ok(commands![FinishRun]) }
+}
+
+/// `paragraph.break`: Ends the current paragraph.
+///
+/// This has the same effect as two subsequent newlines.
+#[derive(Debug, PartialEq)]
+pub struct ParagraphBreak;
+
+function! {
+    data: ParagraphBreak,
+    parse: plain,
+    layout(_, _) { Ok(commands![FinishBox]) }
+}
+
+/// `page.break`: Ends the current page.
+#[derive(Debug, PartialEq)]
+pub struct PageBreak;
+
+function! {
+    data: PageBreak,
+    parse: plain,
+    layout(_, _) { Ok(commands![FinishLayout]) }
+}
+
+macro_rules! space_func {
+    ($ident:ident, $doc:expr, $var:ident => $command:expr) => (
+        #[doc = $doc]
+        #[derive(Debug, PartialEq)]
+        pub struct $ident(Spacing);
+
+        function! {
+            data: $ident,
+
+            parse(args, body, _ctx) {
+                parse!(forbidden: body);
+
+                let arg = args.get_pos::<ArgExpr>()?;
+                let spacing = match arg.val {
+                    Expression::Size(s) => Spacing::Absolute(*s),
+                    Expression::Num(f) => Spacing::Relative(*f as f32),
+                    _ => err!("invalid spacing, expected size or number"),
+                };
+
+                Ok($ident(spacing))
+            }
+
+            layout(this, ctx) {
+                let $var = match this.0 {
+                    Spacing::Absolute(s) => s,
+                    Spacing::Relative(f) => f * ctx.style.font_size,
+                };
+
+                Ok(commands![$command])
+            }
+        }
+    );
+}
+
+/// Absolute or font-relative spacing.
+#[derive(Debug, PartialEq)]
+enum Spacing {
+    Absolute(Size),
+    Relative(f32),
+}
+
+// FIXME: h != primary and v != secondary.
+space_func!(HorizontalSpace, "📖 `h`: Adds horizontal whitespace.",
+    space => AddPrimarySpace(space));
+
+space_func!(VerticalSpace, "📑 `v`: Adds vertical whitespace.",
+    space => AddSecondarySpace(space));