From bdb1c008f2cee7c3929b671d9407d2b578182199 Mon Sep 17 00:00:00 2001
From: Laurenz <laurmaedje@gmail.com>
Date: Wed, 2 Feb 2022 11:28:31 +0100
Subject: [PATCH] Allow set & show only directly in markup

---
 src/eval/mod.rs               |  56 ++++++++++++++++++----------------
 tests/ref/style/set-block.png | Bin 1151 -> 0 bytes
 tests/typ/style/set-block.typ |  10 ------
 tests/typ/style/set.typ       |   5 +++
 tests/typ/style/show.typ      |   5 ++-
 5 files changed, 38 insertions(+), 38 deletions(-)
 delete mode 100644 tests/ref/style/set-block.png
 delete mode 100644 tests/typ/style/set-block.typ
 create mode 100644 tests/typ/style/set.typ

diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 5129a41ff..ebbeec3d4 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -97,8 +97,6 @@ pub struct EvalContext<'a> {
     pub modules: HashMap<SourceId, Module>,
     /// The active scopes.
     pub scopes: Scopes<'a>,
-    /// The active styles.
-    pub styles: StyleMap,
 }
 
 impl<'a> EvalContext<'a> {
@@ -111,7 +109,6 @@ impl<'a> EvalContext<'a> {
             route: vec![source],
             modules: HashMap::new(),
             scopes: Scopes::new(Some(&ctx.std)),
-            styles: StyleMap::new(),
         }
     }
 
@@ -143,7 +140,6 @@ impl<'a> EvalContext<'a> {
         // Prepare the new context.
         let new_scopes = Scopes::new(self.scopes.base);
         let prev_scopes = mem::replace(&mut self.scopes, new_scopes);
-        let prev_styles = mem::take(&mut self.styles);
         self.route.push(id);
 
         // Evaluate the module.
@@ -151,7 +147,6 @@ impl<'a> EvalContext<'a> {
 
         // Restore the old context.
         let new_scopes = mem::replace(&mut self.scopes, prev_scopes);
-        self.styles = prev_styles;
         self.route.pop().unwrap();
 
         // Save the evaluated module.
@@ -178,30 +173,42 @@ impl Eval for Markup {
     type Output = Node;
 
     fn eval(&self, ctx: &mut EvalContext) -> TypResult<Self::Output> {
-        process_nodes(ctx, &mut self.nodes())
+        eval_markup(ctx, &mut self.nodes())
     }
 }
 
-/// Evaluate a stream of nodes.
-fn process_nodes(
+/// Evaluate a stream of markup nodes.
+fn eval_markup(
     ctx: &mut EvalContext,
     nodes: &mut impl Iterator<Item = MarkupNode>,
 ) -> TypResult<Node> {
-    let prev_styles = mem::take(&mut ctx.styles);
     let mut seq = Vec::with_capacity(nodes.size_hint().1.unwrap_or_default());
-    while let Some(piece) = nodes.next() {
-        // Need to deal with wrap here.
-        let node = if let MarkupNode::Expr(Expr::Wrap(wrap)) = piece {
-            let tail = process_nodes(ctx, nodes)?;
-            ctx.scopes.def_mut(wrap.binding().take(), tail);
-            wrap.body().eval(ctx)?.show()
-        } else {
-            piece.eval(ctx)?
+    let mut styles = StyleMap::new();
+
+    while let Some(node) = nodes.next() {
+        let result = match node {
+            MarkupNode::Expr(Expr::Set(set)) => {
+                let class = set.class();
+                let class = class.eval(ctx)?.cast::<Class>().at(class.span())?;
+                let mut args = set.args().eval(ctx)?;
+                class.set(&mut args, &mut styles)?;
+                args.finish()?;
+                continue;
+            }
+            MarkupNode::Expr(Expr::Show(show)) => {
+                return Err("show rules are not yet implemented").at(show.span());
+            }
+            MarkupNode::Expr(Expr::Wrap(wrap)) => {
+                let tail = eval_markup(ctx, nodes)?;
+                ctx.scopes.def_mut(wrap.binding().take(), tail);
+                wrap.body().eval(ctx)?.show()
+            }
+            _ => node.eval(ctx)?,
         };
 
-        seq.push(Styled::new(node, ctx.styles.clone()));
+        seq.push(Styled::new(result, styles.clone()));
     }
-    ctx.styles = prev_styles;
+
     Ok(Node::Sequence(seq))
 }
 
@@ -738,13 +745,8 @@ impl Eval for LetExpr {
 impl Eval for SetExpr {
     type Output = Value;
 
-    fn eval(&self, ctx: &mut EvalContext) -> TypResult<Self::Output> {
-        let class = self.class();
-        let class = class.eval(ctx)?.cast::<Class>().at(class.span())?;
-        let mut args = self.args().eval(ctx)?;
-        class.set(&mut args, &mut ctx.styles)?;
-        args.finish()?;
-        Ok(Value::None)
+    fn eval(&self, _: &mut EvalContext) -> TypResult<Self::Output> {
+        Err("set is only allowed directly in markup").at(self.span())
     }
 }
 
@@ -752,7 +754,7 @@ impl Eval for ShowExpr {
     type Output = Value;
 
     fn eval(&self, _: &mut EvalContext) -> TypResult<Self::Output> {
-        Err("show rules are not yet implemented").at(self.span())
+        Err("show is only allowed directly in markup").at(self.span())
     }
 }
 
diff --git a/tests/ref/style/set-block.png b/tests/ref/style/set-block.png
deleted file mode 100644
index 898c9c6597b0fc241516d7b0fbe9829e908b9002..0000000000000000000000000000000000000000
GIT binary patch
literal 0
HcmV?d00001

literal 1151
zcmeAS@N?(olHy`uVBq!ia0y~yU}OQZyEvGEWVQ4W6`;Vy0G|-o|NsC01EPQb{{H*_
z=ik3SfByXZ`}g<n-{1fI`S$zI=U=~n{P^+h+qbV@zrOwc<IVRUufP3x`Stt9j~}0Y
z`TFkNyGNhC-2eFb=DUyA-hO!c^y$Ud?=HN0clPDmqfcMnx^?To;}?4$J>T>2+3ttW
zb^+0Yr#tRH-FE-U=DUwCUc9*R&ZD)rAFjRiVD+sBD{kCBb?Vg8>vtDlySwPxoufyO
z9yxMk&gEOvF5K9^fB%#V*C(I9KIz=GiRZ5Mow?e3=E}~UJG)L_?mT^Y+qP|OCoi>}
zxVUA@mZswu8jfA4KX!iO#*I}+&Q=^gyJpRr)vH(M??0Kl@5HiY%d+>LSh{p+=APpj
zyN@OAI1<0(aMad=vu4eT*m5v*^MR1f`-3;__gTNkbKP$DwYyx_>~vnev$wa`Vbu=%
zmD}xBZns&n&0^VBv!z>1mu}Htv{7%-#>U1*-Gv);7H-g5uwE00=C9Y7zfOJLx|*6A
zwR!7Q=dD$lyH<Jb+KP&b^78VcqN2RKyquhzw6wH@goN1G*qE4@=;-LEsHn)u$l%~$
zUteEmXJ<!8M-vkh9UUDlEiDZV4HXp?1qB5;IXM{_8F6uOQBhH0VPSrLeqLT)9v&WU
zZf;IaPIh*7W@ct4CMHl62h2=kU|`Dhba4!+xb^nVb$^jS35So(N=fgNj&CY^v#x8w
z4ePRyHyStC1W)(KR!53TN2L9alAq>VVW7l$aYOOG<?nw^zcc%!%J&Jrzfv|wx(GP3
z2ttS-+AKn5N*xMK92mrhdO<HWUkyKwL$}{-zB8$7kw#aP-+B$E1#AAfiI}eSV>#56
zQ~kU{ujN*WRcx(R40k}?*H6DJyI(Jo^>o;Ad!y#P`OX~TOjBZZFo~GQ$gpp)o)h+h
z<3PJQv)#ToeFqu~Omw=m7$l+sLtb!fFuHf@ul(cP$})T7czz#J{QK4Hg)WoLAEOyd
zKW?;P5;>o{meJ4TYku=R1)g7DI4b^IwO<foIe7M(SHm%5Psaw{k5Uh=oj>WIwZ?b(
z<=1?7@3EPvvNBf4*ym<vSBuVP4+?zex1#6N!<6J80f}#4i`6EdOxd^hq%uSBqTYb&
z<tmyS)sOZv*mR^n5lqMm;XS>ml3_}oeB=ubeXBO+4O;uAxi`GZP@7^hPnLOu_MEr}
z9Lf9b-`~1*-%-mdCNwm(SY-|KjJq`}v;KYhRZzT8zP)*__3mxebGc`TvN#H`Jl{5j
zDWGhRC6DwpkzaE!T;`c$v1-52k6>3=EFj_o#QG(5P`wc;I{ru=Jf8-QFI1H-Kc;hh
z6Mmz9!+*p41p9+^O@CPs9Htxo48J*dZk&JN@(uqN@0GDcF)-R|yB<t-Kr+0p`2+Wl
XrDBiWZ-?3d(;kDTtDnm{r-UW|bj~ee

diff --git a/tests/typ/style/set-block.typ b/tests/typ/style/set-block.typ
deleted file mode 100644
index f260acdc4..000000000
--- a/tests/typ/style/set-block.typ
+++ /dev/null
@@ -1,10 +0,0 @@
-// Test set in code blocks.
-
----
-// Test that template in block is not affected by set
-// rule in block ...
-A{set text(fill: eastern); [B]}C
-
----
-// ... no matter the order.
-A{[B]; set text(fill: eastern)}C
diff --git a/tests/typ/style/set.typ b/tests/typ/style/set.typ
new file mode 100644
index 000000000..0d4d47cc0
--- /dev/null
+++ b/tests/typ/style/set.typ
@@ -0,0 +1,5 @@
+// General tests for set.
+
+---
+// Error: 2-10 set is only allowed directly in markup
+{set f(x)}
diff --git a/tests/typ/style/show.typ b/tests/typ/style/show.typ
index 42a35f27b..533e50f54 100644
--- a/tests/typ/style/show.typ
+++ b/tests/typ/style/show.typ
@@ -1,6 +1,9 @@
 // Test show rules.
-// Ref: false
 
 ---
 // Error: 1-34 show rules are not yet implemented
 #show heading(body) as [*{body}*]
+
+---
+// Error: 2-15 show is only allowed directly in markup
+{show (a) as b}