Methods for page and location on queried content

5 files changed, 101 insertions, 43 deletions

diff --git a/src/eval/func.rs b/src/eval/func.rs
index c3ec4233..af80ac92 100644
--- a/src/eval/func.rs
+++ b/src/eval/func.rs
@@ -13,7 +13,7 @@ use super::{
     Vm,
 };
 use crate::diag::{bail, SourceResult, StrResult};
-use crate::model::{NodeId, Selector, StyleMap, Vt};
+use crate::model::{Introspector, NodeId, Selector, StabilityProvider, StyleMap, Vt};
 use crate::syntax::ast::{self, AstNode, Expr};
 use crate::syntax::{SourceId, Span, SyntaxNode};
 use crate::util::hash128;
@@ -102,9 +102,11 @@ impl Func {
 
                 Closure::call(
                     self,
-                    vm.world,
+                    vm.world(),
                     route,
-                    TrackedMut::reborrow_mut(&mut vm.tracer),
+                    TrackedMut::reborrow_mut(&mut vm.vt.tracer),
+                    TrackedMut::reborrow_mut(&mut vm.vt.provider),
+                    vm.vt.introspector,
                     vm.depth + 1,
                     args,
                 )
@@ -125,13 +127,7 @@ impl Func {
         let route = Route::default();
         let id = SourceId::detached();
         let scopes = Scopes::new(None);
-        let mut vm = Vm::new(
-            vt.world,
-            route.track(),
-            TrackedMut::reborrow_mut(&mut vt.tracer),
-            id,
-            scopes,
-        );
+        let mut vm = Vm::new(vt.reborrow_mut(), route.track(), id, scopes);
         let args = Args::new(self.span(), args);
         self.call_vm(&mut vm, args)
     }
@@ -318,6 +314,8 @@ impl Closure {
         world: Tracked<dyn World>,
         route: Tracked<Route>,
         tracer: TrackedMut<Tracer>,
+        provider: TrackedMut<StabilityProvider>,
+        introspector: Tracked<Introspector>,
         depth: usize,
         mut args: Args,
     ) -> SourceResult<Value> {
@@ -358,7 +356,8 @@ impl Closure {
         args.finish()?;
 
         // Evaluate the body.
-        let mut sub = Vm::new(world, route, tracer, closure.location, scopes);
+        let vt = Vt { world, tracer, provider, introspector };
+        let mut sub = Vm::new(vt, route, closure.location, scopes);
         sub.depth = depth;
 
         // Handle control flow.
diff --git a/src/eval/methods.rs b/src/eval/methods.rs
index 036f7ba2..eef825ff 100644
--- a/src/eval/methods.rs
+++ b/src/eval/methods.rs
@@ -73,6 +73,8 @@ 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(),
             _ => return missing(),
         },
 
@@ -249,7 +251,13 @@ pub fn methods_on(type_name: &str) -> &[(&'static str, bool)] {
             ("starts-with", true),
             ("trim", true),
         ],
-        "content" => &[("func", false), ("has", true), ("at", true)],
+        "content" => &[
+            ("func", false),
+            ("has", true),
+            ("at", true),
+            ("page", false),
+            ("location", false),
+        ],
         "array" => &[
             ("all", true),
             ("any", true),
diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 1c002c49..a7f4b825 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -47,7 +47,10 @@ use unicode_segmentation::UnicodeSegmentation;
 use crate::diag::{
     bail, error, At, SourceError, SourceResult, StrResult, Trace, Tracepoint,
 };
+use crate::model::Introspector;
+use crate::model::StabilityProvider;
 use crate::model::Unlabellable;
+use crate::model::Vt;
 use crate::model::{Content, Label, Recipe, Selector, StyleMap, Transform};
 use crate::syntax::ast::AstNode;
 use crate::syntax::{
@@ -81,7 +84,15 @@ pub fn eval(
     // Evaluate the module.
     let route = unsafe { Route::insert(route, id) };
     let scopes = Scopes::new(Some(library));
-    let mut vm = Vm::new(world, route.track(), tracer, id, scopes);
+    let mut provider = StabilityProvider::new();
+    let introspector = Introspector::new(&[]);
+    let vt = Vt {
+        world,
+        tracer,
+        provider: provider.track_mut(),
+        introspector: introspector.track(),
+    };
+    let mut vm = Vm::new(vt, route.track(), id, scopes);
     let root = match source.root().cast::<ast::Markup>() {
         Some(markup) if vm.traced.is_some() => markup,
         _ => source.ast()?,
@@ -121,7 +132,15 @@ pub fn eval_code_str(
     let scopes = Scopes::new(Some(library));
     let route = Route::default();
     let mut tracer = Tracer::default();
-    let mut vm = Vm::new(world, route.track(), tracer.track_mut(), id, scopes);
+    let mut provider = StabilityProvider::new();
+    let introspector = Introspector::new(&[]);
+    let vt = Vt {
+        world,
+        tracer: tracer.track_mut(),
+        provider: provider.track_mut(),
+        introspector: introspector.track(),
+    };
+    let mut vm = Vm::new(vt, route.track(), id, scopes);
     let code = root.cast::<ast::Code>().unwrap();
     let result = code.eval(&mut vm);
 
@@ -138,14 +157,12 @@ pub fn eval_code_str(
 /// Holds the state needed to [evaluate](eval) Typst sources. A new
 /// virtual machine is created for each module evaluation and function call.
 pub struct Vm<'a> {
-    /// The compilation environment.
-    world: Tracked<'a, dyn World>,
+    /// The underlying virtual typesetter.
+    vt: Vt<'a>,
     /// The language items.
     items: LangItems,
     /// The route of source ids the VM took to reach its current location.
     route: Tracked<'a, Route>,
-    /// The tracer for inspection of the values an expression produces.
-    tracer: TrackedMut<'a, Tracer>,
     /// The current location.
     location: SourceId,
     /// A control flow event that is currently happening.
@@ -161,18 +178,17 @@ pub struct Vm<'a> {
 impl<'a> Vm<'a> {
     /// Create a new virtual machine.
     fn new(
-        world: Tracked<'a, dyn World>,
+        vt: Vt<'a>,
         route: Tracked<'a, Route>,
-        tracer: TrackedMut<'a, Tracer>,
         location: SourceId,
         scopes: Scopes<'a>,
     ) -> Self {
-        let traced = tracer.span(location);
+        let traced = vt.tracer.span(location);
+        let items = vt.world.library().items.clone();
         Self {
-            world,
-            items: world.library().items.clone(),
+            vt,
+            items,
             route,
-            tracer,
             location,
             flow: None,
             scopes,
@@ -183,14 +199,14 @@ impl<'a> Vm<'a> {
 
     /// Access the underlying world.
     pub fn world(&self) -> Tracked<'a, dyn World> {
-        self.world
+        self.vt.world
     }
 
     /// Define a variable in the current scope.
     pub fn define(&mut self, var: ast::Ident, value: impl Into<Value>) {
         let value = value.into();
         if self.traced == Some(var.span()) {
-            self.tracer.trace(value.clone());
+            self.vt.tracer.trace(value.clone());
         }
         self.scopes.top.define(var.take(), value);
     }
@@ -200,10 +216,10 @@ impl<'a> Vm<'a> {
     pub fn locate(&self, path: &str) -> StrResult<PathBuf> {
         if !self.location.is_detached() {
             if let Some(path) = path.strip_prefix('/') {
-                return Ok(self.world.root().join(path).normalize());
+                return Ok(self.world().root().join(path).normalize());
             }
 
-            if let Some(dir) = self.world.source(self.location).path().parent() {
+            if let Some(dir) = self.world().source(self.location).path().parent() {
                 return Ok(dir.join(path).normalize());
             }
         }
@@ -450,7 +466,7 @@ impl Eval for ast::Expr {
         .spanned(span);
 
         if vm.traced == Some(span) {
-            vm.tracer.trace(v.clone());
+            vm.vt.tracer.trace(v.clone());
         }
 
         Ok(v)
@@ -1004,16 +1020,22 @@ impl Eval for ast::FuncCall {
                 let args = args.eval(vm)?;
                 let target = target.access(vm)?;
                 if !matches!(target, Value::Symbol(_) | Value::Module(_)) {
-                    return methods::call_mut(target, &field, args, span)
-                        .trace(vm.world, point, span);
+                    return methods::call_mut(target, &field, args, span).trace(
+                        vm.world(),
+                        point,
+                        span,
+                    );
                 }
                 (target.field(&field).at(field_span)?, args)
             } else {
                 let target = target.eval(vm)?;
                 let args = args.eval(vm)?;
                 if !matches!(target, Value::Symbol(_) | Value::Module(_)) {
-                    return methods::call(vm, target, &field, args, span)
-                        .trace(vm.world, point, span);
+                    return methods::call(vm, target, &field, args, span).trace(
+                        vm.world(),
+                        point,
+                        span,
+                    );
                 }
                 (target.field(&field).at(field_span)?, args)
             }
@@ -1052,7 +1074,7 @@ impl Eval for ast::FuncCall {
 
         let callee = callee.cast::<Func>().at(callee_span)?;
         let point = || Tracepoint::Call(callee.name().map(Into::into));
-        callee.call_vm(vm, args).trace(vm.world, point, span)
+        callee.call_vm(vm, args).trace(vm.world(), point, span)
     }
 }
 
@@ -1431,8 +1453,9 @@ fn import(vm: &mut Vm, source: Value, span: Span) -> SourceResult<Module> {
     };
 
     // Load the source file.
+    let world = vm.world();
     let full = vm.locate(&path).at(span)?;
-    let id = vm.world.resolve(&full).at(span)?;
+    let id = world.resolve(&full).at(span)?;
 
     // Prevent cyclic importing.
     if vm.route.contains(id) {
@@ -1440,10 +1463,10 @@ fn import(vm: &mut Vm, source: Value, span: Span) -> SourceResult<Module> {
     }
 
     // Evaluate the file.
-    let source = vm.world.source(id);
+    let source = world.source(id);
     let point = || Tracepoint::Import;
-    eval(vm.world, vm.route, TrackedMut::reborrow_mut(&mut vm.tracer), source)
-        .trace(vm.world, point, span)
+    eval(world, vm.route, TrackedMut::reborrow_mut(&mut vm.vt.tracer), source)
+        .trace(world, point, span)
 }
 
 impl Eval for ast::LoopBreak {
@@ -1506,7 +1529,7 @@ impl Access for ast::Ident {
         let span = self.span();
         let value = vm.scopes.get_mut(self).at(span)?;
         if vm.traced == Some(span) {
-            vm.tracer.trace(value.clone());
+            vm.vt.tracer.trace(value.clone());
         }
         Ok(value)
     }
diff --git a/src/model/content.rs b/src/model/content.rs
index 5317236e..3c661929 100644
--- a/src/model/content.rs
+++ b/src/model/content.rs
@@ -2,6 +2,7 @@ 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};
@@ -9,10 +10,10 @@ use once_cell::sync::Lazy;
 
 use super::{
     node, Behave, Behaviour, Fold, Guard, Locatable, Recipe, StableId, Style, StyleMap,
-    Synthesize,
+    Synthesize, Vt,
 };
 use crate::diag::{SourceResult, StrResult};
-use crate::doc::Meta;
+use crate::doc::{Location, Meta};
 use crate::eval::{
     cast_from_value, cast_to_value, Args, Cast, Func, FuncInfo, Str, Value, Vm,
 };
@@ -185,6 +186,22 @@ 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/typeset.rs b/src/model/typeset.rs
index 683f2846..162a2a67 100644
--- a/src/model/typeset.rs
+++ b/src/model/typeset.rs
@@ -53,8 +53,7 @@ pub fn typeset(
 
 /// A virtual typesetter.
 ///
-/// Holds the state needed to [typeset] content. This is the equivalent to the
-/// [Vm](crate::eval::Vm) for typesetting.
+/// Holds the state needed to [typeset] content.
 pub struct Vt<'a> {
     /// The compilation environment.
     pub world: Tracked<'a, dyn World>,
@@ -66,6 +65,18 @@ pub struct Vt<'a> {
     pub introspector: Tracked<'a, Introspector>,
 }
 
+impl Vt<'_> {
+    /// Mutably reborrow with a shorter lifetime.
+    pub fn reborrow_mut(&mut self) -> Vt<'_> {
+        Vt {
+            world: self.world,
+            tracer: TrackedMut::reborrow_mut(&mut self.tracer),
+            provider: TrackedMut::reborrow_mut(&mut self.provider),
+            introspector: self.introspector,
+        }
+    }
+}
+
 /// Provides stable identities to nodes.
 #[derive(Clone)]
 pub struct StabilityProvider {