Measurement and introspection rework

5 files changed, 65 insertions, 57 deletions

diff --git a/src/eval/library.rs b/src/eval/library.rs
index 485a766b..eae342c2 100644
--- a/src/eval/library.rs
+++ b/src/eval/library.rs
@@ -6,7 +6,7 @@ use comemo::Tracked;
 use ecow::EcoString;
 use once_cell::sync::OnceCell;
 
-use super::{Args, Dynamic, Module, Value};
+use super::{Args, Dynamic, Module, Value, Vm};
 use crate::diag::SourceResult;
 use crate::doc::Document;
 use crate::geom::{Abs, Dir};
@@ -92,6 +92,7 @@ pub struct LangItems {
     pub math_frac: fn(num: Content, denom: Content) -> Content,
     /// Dispatch a method on a library value.
     pub library_method: fn(
+        vm: &mut Vm,
         dynamic: &Dynamic,
         method: &str,
         args: Args,
diff --git a/src/eval/methods.rs b/src/eval/methods.rs
index eef825ff..324191ab 100644
--- a/src/eval/methods.rs
+++ b/src/eval/methods.rs
@@ -4,6 +4,7 @@ use ecow::EcoString;
 
 use super::{Args, Str, Value, Vm};
 use crate::diag::{At, SourceResult};
+use crate::model::StableId;
 use crate::syntax::Span;
 
 /// Call a method on a value.
@@ -73,8 +74,11 @@ pub fn call(
             "func" => Value::Func(content.id().into()),
             "has" => Value::Bool(content.has(&args.expect::<EcoString>("field")?)),
             "at" => content.at(&args.expect::<EcoString>("field")?).at(span)?.clone(),
-            "page" => content.page(&vm.vt).at(span)?.into(),
-            "location" => content.location(&vm.vt).at(span)?.into(),
+            "id" => content
+                .stable_id()
+                .ok_or("this method can only be called on content returned by query()")
+                .at(span)?
+                .into(),
             _ => return missing(),
         },
 
@@ -137,7 +141,15 @@ pub fn call(
         },
 
         Value::Dyn(dynamic) => {
-            return (vm.items.library_method)(&dynamic, method, args, span);
+            if let Some(&id) = dynamic.downcast::<StableId>() {
+                match method {
+                    "page" => vm.vt.introspector.page(id).into(),
+                    "location" => vm.vt.introspector.location(id).into(),
+                    _ => return missing(),
+                }
+            } else {
+                return (vm.items.library_method)(vm, &dynamic, method, args, span);
+            }
         }
 
         _ => return missing(),
@@ -251,13 +263,7 @@ pub fn methods_on(type_name: &str) -> &[(&'static str, bool)] {
             ("starts-with", true),
             ("trim", true),
         ],
-        "content" => &[
-            ("func", false),
-            ("has", true),
-            ("at", true),
-            ("page", false),
-            ("location", false),
-        ],
+        "content" => &[("func", false), ("has", true), ("at", true), ("id", false)],
         "array" => &[
             ("all", true),
             ("any", true),
@@ -293,14 +299,15 @@ pub fn methods_on(type_name: &str) -> &[(&'static str, bool)] {
         ],
         "function" => &[("where", true), ("with", true)],
         "arguments" => &[("named", false), ("pos", false)],
+        "stable id" => &[("page", false), ("location", false)],
         "counter" => &[
-            ("get", true),
+            ("display", true),
+            ("at", true),
             ("final", true),
-            ("both", true),
             ("step", true),
             ("update", true),
         ],
-        "state" => &[("get", true), ("final", true), ("update", true)],
+        "state" => &[("display", true), ("at", true), ("final", true), ("update", true)],
         _ => &[],
     }
 }
diff --git a/src/model/content.rs b/src/model/content.rs
index 3c661929..5317236e 100644
--- a/src/model/content.rs
+++ b/src/model/content.rs
@@ -2,7 +2,6 @@ use std::any::TypeId;
 use std::fmt::{self, Debug, Formatter, Write};
 use std::hash::{Hash, Hasher};
 use std::iter::{self, Sum};
-use std::num::NonZeroUsize;
 use std::ops::{Add, AddAssign, Deref};
 
 use ecow::{eco_format, EcoString, EcoVec};
@@ -10,10 +9,10 @@ use once_cell::sync::Lazy;
 
 use super::{
     node, Behave, Behaviour, Fold, Guard, Locatable, Recipe, StableId, Style, StyleMap,
-    Synthesize, Vt,
+    Synthesize,
 };
 use crate::diag::{SourceResult, StrResult};
-use crate::doc::{Location, Meta};
+use crate::doc::Meta;
 use crate::eval::{
     cast_from_value, cast_to_value, Args, Cast, Func, FuncInfo, Str, Value, Vm,
 };
@@ -186,22 +185,6 @@ impl Content {
         self.field(field).ok_or_else(|| missing_field(field))
     }
 
-    /// Determine the page of this content.
-    pub fn page(&self, vt: &Vt) -> StrResult<NonZeroUsize> {
-        match self.stable_id() {
-            Some(id) => Ok(vt.introspector.page(id)),
-            None => Err("this method can only be called on queried content".into()),
-        }
-    }
-
-    /// Determine the location of this content.
-    pub fn location(&self, vt: &Vt) -> StrResult<Location> {
-        match self.stable_id() {
-            Some(id) => Ok(vt.introspector.location(id)),
-            None => Err("this method can only be called on queried content".into()),
-        }
-    }
-
     /// The content's label.
     pub fn label(&self) -> Option<&Label> {
         match self.field("label")? {
diff --git a/src/model/styles.rs b/src/model/styles.rs
index 7b725af9..b7d09774 100644
--- a/src/model/styles.rs
+++ b/src/model/styles.rs
@@ -78,13 +78,7 @@ impl PartialEq for StyleMap {
 
 impl Debug for StyleMap {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        if let [style] = self.0.as_slice() {
-            return style.fmt(f);
-        }
-
-        let pieces: Vec<_> =
-            self.0.iter().map(|value| eco_format!("{value:?}")).collect();
-        f.write_str(&pretty_array_like(&pieces, false))
+        f.pad("..")
     }
 }
 
diff --git a/src/model/typeset.rs b/src/model/typeset.rs
index 162a2a67..8216d7a8 100644
--- a/src/model/typeset.rs
+++ b/src/model/typeset.rs
@@ -1,3 +1,4 @@
+use std::fmt::{self, Debug, Formatter};
 use std::hash::Hash;
 use std::num::NonZeroUsize;
 
@@ -6,7 +7,7 @@ use comemo::{Constraint, Track, Tracked, TrackedMut};
 use super::{Content, Selector, StyleChain};
 use crate::diag::SourceResult;
 use crate::doc::{Document, Element, Frame, Location, Meta};
-use crate::eval::Tracer;
+use crate::eval::{cast_from_value, Tracer};
 use crate::geom::{Point, Transform};
 use crate::util::NonZeroExt;
 use crate::World;
@@ -116,7 +117,7 @@ impl StabilityProvider {
 /// Stably identifies a call site across multiple layout passes.
 ///
 /// This struct is created by [`StabilityProvider::identify`].
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub struct StableId(u128, usize, usize);
 
 impl StableId {
@@ -126,16 +127,27 @@ impl StableId {
     }
 }
 
+impl Debug for StableId {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.pad("..")
+    }
+}
+
+cast_from_value! {
+    StableId: "stable id",
+}
+
 /// Provides access to information about the document.
 pub struct Introspector {
     init: bool,
+    pages: usize,
     nodes: Vec<(Content, Location)>,
 }
 
 impl Introspector {
     /// Create a new introspector.
     pub fn new(frames: &[Frame]) -> Self {
-        let mut introspector = Self { init: false, nodes: vec![] };
+        let mut introspector = Self { init: false, pages: frames.len(), nodes: vec![] };
         for (i, frame) in frames.iter().enumerate() {
             let page = NonZeroUsize::new(1 + i).unwrap();
             introspector.extract(frame, page, Transform::identity());
@@ -180,26 +192,37 @@ impl Introspector {
         self.init
     }
 
-    /// Query for all metadata matches for the given selector.
+    /// Query for all nodes for the given selector.
     pub fn query(&self, selector: Selector) -> Vec<Content> {
         self.all().filter(|node| selector.matches(node)).cloned().collect()
     }
 
-    /// Query for all metadata matches before the given id.
-    pub fn query_split(
-        &self,
-        selector: Selector,
-        id: StableId,
-    ) -> (Vec<Content>, Vec<Content>) {
-        let mut iter = self.all();
-        let before = iter
-            .by_ref()
-            .take_while(|node| node.stable_id() != Some(id))
+    /// Query for all nodes up to the given id.
+    pub fn query_before(&self, selector: Selector, id: StableId) -> Vec<Content> {
+        let mut matches = vec![];
+        for node in self.all() {
+            if selector.matches(node) {
+                matches.push(node.clone());
+            }
+            if node.stable_id() == Some(id) {
+                break;
+            }
+        }
+        matches
+    }
+
+    /// Query for all nodes starting from the given id.
+    pub fn query_after(&self, selector: Selector, id: StableId) -> Vec<Content> {
+        self.all()
+            .skip_while(|node| node.stable_id() != Some(id))
             .filter(|node| selector.matches(node))
             .cloned()
-            .collect();
-        let after = iter.filter(|node| selector.matches(node)).cloned().collect();
-        (before, after)
+            .collect()
+    }
+
+    /// The total number pages.
+    pub fn pages(&self) -> NonZeroUsize {
+        NonZeroUsize::new(self.pages).unwrap_or(NonZeroUsize::ONE)
     }
 
     /// Find the page number for the given stable id.