Split up `model` module

1 files changed, 0 insertions, 576 deletions

diff --git a/src/model/func.rs b/src/model/func.rs
deleted file mode 100644
index 2ba462d3..00000000
--- a/src/model/func.rs
+++ /dev/null
@@ -1,576 +0,0 @@
-use std::fmt::{self, Debug, Formatter};
-use std::hash::{Hash, Hasher};
-use std::sync::Arc;
-
-use comemo::{Prehashed, Track, Tracked, TrackedMut};
-use ecow::EcoString;
-
-use super::{
-    Args, CastInfo, Dict, Eval, Flow, Node, NodeId, Route, Scope, Scopes, Selector,
-    StyleMap, Tracer, Value, Vm,
-};
-use crate::diag::{bail, SourceResult, StrResult};
-use crate::syntax::ast::{self, AstNode, Expr};
-use crate::syntax::{SourceId, Span, SyntaxNode};
-use crate::util::hash128;
-use crate::World;
-
-/// An evaluatable function.
-#[derive(Clone, Hash)]
-pub struct Func(Arc<Prehashed<Repr>>, Span);
-
-/// The different kinds of function representations.
-#[derive(Hash)]
-enum Repr {
-    /// A native rust function.
-    Native(Native),
-    /// A user-defined closure.
-    Closure(Closure),
-    /// A nested function with pre-applied arguments.
-    With(Func, Args),
-}
-
-impl Func {
-    /// Create a new function from a type that can be turned into a function.
-    pub fn from_type<T: FuncType>(name: &'static str) -> Self {
-        T::create_func(name)
-    }
-
-    /// Create a new function from a native rust function.
-    pub fn from_fn(
-        func: fn(&Vm, &mut Args) -> SourceResult<Value>,
-        info: FuncInfo,
-    ) -> Self {
-        Self(
-            Arc::new(Prehashed::new(Repr::Native(Native {
-                func,
-                set: None,
-                node: None,
-                info,
-            }))),
-            Span::detached(),
-        )
-    }
-
-    /// Create a new function from a native rust node.
-    pub fn from_node<T: Node>(mut info: FuncInfo) -> Self {
-        info.params.extend(T::properties());
-        Self(
-            Arc::new(Prehashed::new(Repr::Native(Native {
-                func: |ctx, args| {
-                    let styles = T::set(args, true)?;
-                    let content = T::construct(ctx, args)?;
-                    Ok(Value::Content(content.styled_with_map(styles.scoped())))
-                },
-                set: Some(|args| T::set(args, false)),
-                node: Some(NodeId::of::<T>()),
-                info,
-            }))),
-            Span::detached(),
-        )
-    }
-
-    /// Create a new function from a closure.
-    pub(super) fn from_closure(closure: Closure, span: Span) -> Self {
-        Self(Arc::new(Prehashed::new(Repr::Closure(closure))), span)
-    }
-
-    /// The name of the function.
-    pub fn name(&self) -> Option<&str> {
-        match &**self.0 {
-            Repr::Native(native) => Some(native.info.name),
-            Repr::Closure(closure) => closure.name.as_deref(),
-            Repr::With(func, _) => func.name(),
-        }
-    }
-
-    /// Extract details the function.
-    pub fn info(&self) -> Option<&FuncInfo> {
-        match &**self.0 {
-            Repr::Native(native) => Some(&native.info),
-            Repr::With(func, _) => func.info(),
-            _ => None,
-        }
-    }
-
-    /// The function's span.
-    pub fn span(&self) -> Span {
-        self.1
-    }
-
-    /// Attach a span to the function.
-    pub fn spanned(mut self, span: Span) -> Self {
-        self.1 = span;
-        self
-    }
-
-    /// The number of positional arguments this function takes, if known.
-    pub fn argc(&self) -> Option<usize> {
-        match &**self.0 {
-            Repr::Closure(closure) => closure.argc(),
-            Repr::With(wrapped, applied) => Some(wrapped.argc()?.saturating_sub(
-                applied.items.iter().filter(|arg| arg.name.is_none()).count(),
-            )),
-            _ => None,
-        }
-    }
-
-    /// Call the function with the given arguments.
-    pub fn call(&self, vm: &mut Vm, mut args: Args) -> SourceResult<Value> {
-        match &**self.0 {
-            Repr::Native(native) => {
-                let value = (native.func)(vm, &mut args)?;
-                args.finish()?;
-                Ok(value)
-            }
-            Repr::Closure(closure) => {
-                // Determine the route inside the closure.
-                let fresh = Route::new(closure.location);
-                let route =
-                    if vm.location.is_detached() { fresh.track() } else { vm.route };
-
-                Closure::call(
-                    self,
-                    vm.world,
-                    route,
-                    TrackedMut::reborrow_mut(&mut vm.tracer),
-                    vm.depth + 1,
-                    args,
-                )
-            }
-            Repr::With(wrapped, applied) => {
-                args.items = applied.items.iter().cloned().chain(args.items).collect();
-                return wrapped.call(vm, args);
-            }
-        }
-    }
-
-    /// Call the function without an existing virtual machine.
-    pub fn call_detached(
-        &self,
-        world: Tracked<dyn World>,
-        args: Args,
-    ) -> SourceResult<Value> {
-        let route = Route::default();
-        let id = SourceId::detached();
-        let scopes = Scopes::new(None);
-        let mut tracer = Tracer::default();
-        let mut vm = Vm::new(world, route.track(), tracer.track_mut(), id, scopes, 0);
-        self.call(&mut vm, args)
-    }
-
-    /// Apply the given arguments to the function.
-    pub fn with(self, args: Args) -> Self {
-        let span = self.1;
-        Self(Arc::new(Prehashed::new(Repr::With(self, args))), span)
-    }
-
-    /// Create a selector for this function's node type, filtering by node's
-    /// whose [fields](super::Content::field) match the given arguments.
-    pub fn where_(self, args: &mut Args) -> StrResult<Selector> {
-        let fields = args.to_named();
-        args.items.retain(|arg| arg.name.is_none());
-        self.select(Some(fields))
-    }
-
-    /// Execute the function's set rule and return the resulting style map.
-    pub fn set(&self, mut args: Args) -> SourceResult<StyleMap> {
-        Ok(match &**self.0 {
-            Repr::Native(Native { set: Some(set), .. }) => {
-                let styles = set(&mut args)?;
-                args.finish()?;
-                styles
-            }
-            _ => StyleMap::new(),
-        })
-    }
-
-    /// Create a selector for this function's node type.
-    pub fn select(&self, fields: Option<Dict>) -> StrResult<Selector> {
-        match **self.0 {
-            Repr::Native(Native { node: Some(id), .. }) => {
-                if id == item!(text_id) {
-                    Err("to select text, please use a string or regex instead")?;
-                }
-
-                Ok(Selector::Node(id, fields))
-            }
-            _ => Err("this function is not selectable")?,
-        }
-    }
-}
-
-impl Debug for Func {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self.name() {
-            Some(name) => write!(f, "<function {name}>"),
-            None => f.write_str("<function>"),
-        }
-    }
-}
-
-impl PartialEq for Func {
-    fn eq(&self, other: &Self) -> bool {
-        hash128(&self.0) == hash128(&other.0)
-    }
-}
-
-/// Types that can be turned into functions.
-pub trait FuncType {
-    /// Create a function with the given name from this type.
-    fn create_func(name: &'static str) -> Func;
-}
-
-/// A function defined by a native rust function or node.
-struct Native {
-    /// The function pointer.
-    func: fn(&Vm, &mut Args) -> SourceResult<Value>,
-    /// The set rule.
-    set: Option<fn(&mut Args) -> SourceResult<StyleMap>>,
-    /// The id of the node to customize with this function's show rule.
-    node: Option<NodeId>,
-    /// Documentation of the function.
-    info: FuncInfo,
-}
-
-impl Hash for Native {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        (self.func as usize).hash(state);
-        self.set.map(|set| set as usize).hash(state);
-        self.node.hash(state);
-    }
-}
-
-/// Details about a function.
-#[derive(Debug, Clone)]
-pub struct FuncInfo {
-    /// The function's name.
-    pub name: &'static str,
-    /// The display name of the function.
-    pub display: &'static str,
-    /// Documentation for the function.
-    pub docs: &'static str,
-    /// Details about the function's parameters.
-    pub params: Vec<ParamInfo>,
-    /// Valid types for the return value.
-    pub returns: Vec<&'static str>,
-    /// Which category the function is part of.
-    pub category: &'static str,
-}
-
-impl FuncInfo {
-    /// Get the parameter info for a parameter with the given name
-    pub fn param(&self, name: &str) -> Option<&ParamInfo> {
-        self.params.iter().find(|param| param.name == name)
-    }
-}
-
-/// Describes a named parameter.
-#[derive(Debug, Clone)]
-pub struct ParamInfo {
-    /// The parameter's name.
-    pub name: &'static str,
-    /// Documentation for the parameter.
-    pub docs: &'static str,
-    /// Valid values for the parameter.
-    pub cast: CastInfo,
-    /// Is the parameter positional?
-    pub positional: bool,
-    /// Is the parameter named?
-    ///
-    /// Can be true even if `positional` is true if the parameter can be given
-    /// in both variants.
-    pub named: bool,
-    /// Is the parameter required?
-    pub required: bool,
-    /// Can the parameter be given any number of times?
-    pub variadic: bool,
-    /// Is the parameter settable with a set rule?
-    pub settable: bool,
-}
-
-/// A user-defined closure.
-#[derive(Hash)]
-pub(super) struct Closure {
-    /// The source file where the closure was defined.
-    pub location: SourceId,
-    /// The name of the closure.
-    pub name: Option<EcoString>,
-    /// Captured values from outer scopes.
-    pub captured: Scope,
-    /// The parameter names and default values. Parameters with default value
-    /// are named parameters.
-    pub params: Vec<(EcoString, Option<Value>)>,
-    /// The name of an argument sink where remaining arguments are placed.
-    pub sink: Option<EcoString>,
-    /// The expression the closure should evaluate to.
-    pub body: Expr,
-}
-
-impl Closure {
-    /// Call the function in the context with the arguments.
-    #[comemo::memoize]
-    fn call(
-        this: &Func,
-        world: Tracked<dyn World>,
-        route: Tracked<Route>,
-        tracer: TrackedMut<Tracer>,
-        depth: usize,
-        mut args: Args,
-    ) -> SourceResult<Value> {
-        let closure = match &**this.0 {
-            Repr::Closure(closure) => closure,
-            _ => panic!("`this` must be a closure"),
-        };
-
-        // Don't leak the scopes from the call site. Instead, we use the scope
-        // of captured variables we collected earlier.
-        let mut scopes = Scopes::new(None);
-        scopes.top = closure.captured.clone();
-
-        // Provide the closure itself for recursive calls.
-        if let Some(name) = &closure.name {
-            scopes.top.define(name.clone(), Value::Func(this.clone()));
-        }
-
-        // Parse the arguments according to the parameter list.
-        for (param, default) in &closure.params {
-            scopes.top.define(
-                param.clone(),
-                match default {
-                    Some(default) => {
-                        args.named::<Value>(param)?.unwrap_or_else(|| default.clone())
-                    }
-                    None => args.expect::<Value>(param)?,
-                },
-            );
-        }
-
-        // Put the remaining arguments into the sink.
-        if let Some(sink) = &closure.sink {
-            scopes.top.define(sink.clone(), args.take());
-        }
-
-        // Ensure all arguments have been used.
-        args.finish()?;
-
-        // Evaluate the body.
-        let mut sub = Vm::new(world, route, tracer, closure.location, scopes, depth);
-        let result = closure.body.eval(&mut sub);
-
-        // Handle control flow.
-        match sub.flow {
-            Some(Flow::Return(_, Some(explicit))) => return Ok(explicit),
-            Some(Flow::Return(_, None)) => {}
-            Some(flow) => bail!(flow.forbidden()),
-            None => {}
-        }
-
-        result
-    }
-
-    /// The number of positional arguments this function takes, if known.
-    fn argc(&self) -> Option<usize> {
-        if self.sink.is_some() {
-            return None;
-        }
-
-        Some(self.params.iter().filter(|(_, default)| default.is_none()).count())
-    }
-}
-
-/// A visitor that determines which variables to capture for a closure.
-pub(super) struct CapturesVisitor<'a> {
-    external: &'a Scopes<'a>,
-    internal: Scopes<'a>,
-    captures: Scope,
-}
-
-impl<'a> CapturesVisitor<'a> {
-    /// Create a new visitor for the given external scopes.
-    pub fn new(external: &'a Scopes) -> Self {
-        Self {
-            external,
-            internal: Scopes::new(None),
-            captures: Scope::new(),
-        }
-    }
-
-    /// Return the scope of captured variables.
-    pub fn finish(self) -> Scope {
-        self.captures
-    }
-
-    /// Visit any node and collect all captured variables.
-    pub fn visit(&mut self, node: &SyntaxNode) {
-        match node.cast() {
-            // Every identifier is a potential variable that we need to capture.
-            // Identifiers that shouldn't count as captures because they
-            // actually bind a new name are handled below (individually through
-            // the expressions that contain them).
-            Some(ast::Expr::Ident(ident)) => self.capture(ident),
-            Some(ast::Expr::MathIdent(ident)) => self.capture_in_math(ident),
-
-            // Code and content blocks create a scope.
-            Some(ast::Expr::Code(_) | ast::Expr::Content(_)) => {
-                self.internal.enter();
-                for child in node.children() {
-                    self.visit(child);
-                }
-                self.internal.exit();
-            }
-
-            // A closure contains parameter bindings, which are bound before the
-            // body is evaluated. Care must be taken so that the default values
-            // of named parameters cannot access previous parameter bindings.
-            Some(ast::Expr::Closure(expr)) => {
-                for param in expr.params() {
-                    if let ast::Param::Named(named) = param {
-                        self.visit(named.expr().as_untyped());
-                    }
-                }
-
-                self.internal.enter();
-                if let Some(name) = expr.name() {
-                    self.bind(name);
-                }
-
-                for param in expr.params() {
-                    match param {
-                        ast::Param::Pos(ident) => self.bind(ident),
-                        ast::Param::Named(named) => self.bind(named.name()),
-                        ast::Param::Sink(ident) => self.bind(ident),
-                    }
-                }
-
-                self.visit(expr.body().as_untyped());
-                self.internal.exit();
-            }
-
-            // A let expression contains a binding, but that binding is only
-            // active after the body is evaluated.
-            Some(ast::Expr::Let(expr)) => {
-                if let Some(init) = expr.init() {
-                    self.visit(init.as_untyped());
-                }
-                self.bind(expr.binding());
-            }
-
-            // A for loop contains one or two bindings in its pattern. These are
-            // active after the iterable is evaluated but before the body is
-            // evaluated.
-            Some(ast::Expr::For(expr)) => {
-                self.visit(expr.iter().as_untyped());
-                self.internal.enter();
-                let pattern = expr.pattern();
-                if let Some(key) = pattern.key() {
-                    self.bind(key);
-                }
-                self.bind(pattern.value());
-                self.visit(expr.body().as_untyped());
-                self.internal.exit();
-            }
-
-            // An import contains items, but these are active only after the
-            // path is evaluated.
-            Some(ast::Expr::Import(expr)) => {
-                self.visit(expr.source().as_untyped());
-                if let Some(ast::Imports::Items(items)) = expr.imports() {
-                    for item in items {
-                        self.bind(item);
-                    }
-                }
-            }
-
-            // Everything else is traversed from left to right.
-            _ => {
-                for child in node.children() {
-                    self.visit(child);
-                }
-            }
-        }
-    }
-
-    /// Bind a new internal variable.
-    fn bind(&mut self, ident: ast::Ident) {
-        self.internal.top.define(ident.take(), Value::None);
-    }
-
-    /// Capture a variable if it isn't internal.
-    fn capture(&mut self, ident: ast::Ident) {
-        if self.internal.get(&ident).is_err() {
-            if let Ok(value) = self.external.get(&ident) {
-                self.captures.define_captured(ident.take(), value.clone());
-            }
-        }
-    }
-
-    /// Capture a variable in math mode if it isn't internal.
-    fn capture_in_math(&mut self, ident: ast::MathIdent) {
-        if self.internal.get(&ident).is_err() {
-            if let Ok(value) = self.external.get_in_math(&ident) {
-                self.captures.define_captured(ident.take(), value.clone());
-            }
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::syntax::parse;
-
-    #[track_caller]
-    fn test(text: &str, result: &[&str]) {
-        let mut scopes = Scopes::new(None);
-        scopes.top.define("f", 0);
-        scopes.top.define("x", 0);
-        scopes.top.define("y", 0);
-        scopes.top.define("z", 0);
-
-        let mut visitor = CapturesVisitor::new(&scopes);
-        let root = parse(text);
-        visitor.visit(&root);
-
-        let captures = visitor.finish();
-        let mut names: Vec<_> = captures.iter().map(|(k, _)| k).collect();
-        names.sort();
-
-        assert_eq!(names, result);
-    }
-
-    #[test]
-    fn test_captures() {
-        // Let binding and function definition.
-        test("#let x = x", &["x"]);
-        test("#let x; #(x + y)", &["y"]);
-        test("#let f(x, y) = x + y", &[]);
-        test("#let f(x, y) = f", &[]);
-        test("#let f = (x, y) => f", &["f"]);
-
-        // Closure with different kinds of params.
-        test("#((x, y) => x + z)", &["z"]);
-        test("#((x: y, z) => x + z)", &["y"]);
-        test("#((..x) => x + y)", &["y"]);
-        test("#((x, y: x + z) => x + y)", &["x", "z"]);
-        test("#{x => x; x}", &["x"]);
-
-        // Show rule.
-        test("#show y: x => x", &["y"]);
-        test("#show y: x => x + z", &["y", "z"]);
-        test("#show x: x => x", &["x"]);
-
-        // For loop.
-        test("#for x in y { x + z }", &["y", "z"]);
-        test("#for x, y in y { x + y }", &["y"]);
-        test("#for x in y {} #x", &["x", "y"]);
-
-        // Import.
-        test("#import z: x, y", &["z"]);
-        test("#import x + y: x, y, z", &["x", "y"]);
-
-        // Blocks.
-        test("#{ let x = 1; { let y = 2; y }; x + y }", &["y"]);
-        test("#[#let x = 1]#x", &["x"]);
-    }
-}