Automatic rules registration

src/elements/code.rs

@@ -296,6 +296,7 @@ impl Element for Code {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct CodeRule {
 	re: [Regex; 2],
 	properties: PropertyParser,
@@ -330,6 +331,7 @@ impl CodeRule {
 
 impl RegexRule for CodeRule {
 	fn name(&self) -> &'static str { "Code" }
+	fn previous(&self) -> Option<&'static str> { Some("List") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/comment.rs

@@ -38,6 +38,7 @@ impl Element for Comment {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct CommentRule {
 	re: [Regex; 1],
 }
@@ -53,6 +54,8 @@ impl CommentRule {
 impl RegexRule for CommentRule {
 	fn name(&self) -> &'static str { "Comment" }
 
+	fn previous(&self) -> Option<&'static str> { None }
+
 	fn regexes(&self) -> &[Regex] { &self.re }
 
 	fn on_regex_match<'a>(

src/elements/customstyle.rs

@@ -178,10 +178,16 @@ impl RuleState for CustomStyleState {
 
 static STATE_NAME: &'static str = "elements.custom_style";
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct CustomStyleRule;
 
+impl CustomStyleRule {
+	pub fn new() -> Self { Self{} }
+}
+
 impl Rule for CustomStyleRule {
 	fn name(&self) -> &'static str { "Custom Style" }
+	fn previous(&self) -> Option<&'static str> { Some("Style") }
 
 	fn next_match(&self, state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
 		let content = cursor.source.content();

src/elements/elemstyle.rs

@@ -21,6 +21,7 @@ use crate::parser::rule::Rule;
 use crate::parser::source::Cursor;
 use crate::parser::source::Source;
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ElemStyleRule {
 	start_re: Regex,
 }
@@ -58,6 +59,7 @@ impl ElemStyleRule {
 
 impl Rule for ElemStyleRule {
 	fn name(&self) -> &'static str { "Element Style" }
+	fn previous(&self) -> Option<&'static str> { Some("Script") }
 
 	fn next_match(&self, _state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
 		self.start_re

src/elements/graphviz.rs

@@ -146,6 +146,7 @@ impl Element for Graphviz {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct GraphRule {
 	re: [Regex; 1],
 	properties: PropertyParser,
@@ -178,6 +179,7 @@ impl GraphRule {
 
 impl RegexRule for GraphRule {
 	fn name(&self) -> &'static str { "Graph" }
+	fn previous(&self) -> Option<&'static str> { Some("Tex") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/import.rs

@@ -17,6 +17,7 @@ use std::rc::Rc;
 
 use super::paragraph::Paragraph;
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ImportRule {
 	re: [Regex; 1],
 }
@@ -40,6 +41,7 @@ impl ImportRule {
 
 impl RegexRule for ImportRule {
 	fn name(&self) -> &'static str { "Import" }
+	fn previous(&self) -> Option<&'static str> { Some("Paragraph") }
 
 	fn regexes(&self) -> &[Regex] { &self.re }
 

src/elements/layout.rs

@@ -284,6 +284,7 @@ impl RuleState for LayoutState {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct LayoutRule {
 	re: [Regex; 3],
 }
@@ -378,6 +379,7 @@ static STATE_NAME: &'static str = "elements.layout";
 
 impl RegexRule for LayoutRule {
 	fn name(&self) -> &'static str { "Layout" }
+	fn previous(&self) -> Option<&'static str> { Some("Media") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/link.rs

@@ -71,6 +71,7 @@ impl ContainerElement for Link {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct LinkRule {
 	re: [Regex; 1],
 }
@@ -85,6 +86,7 @@ impl LinkRule {
 
 impl RegexRule for LinkRule {
 	fn name(&self) -> &'static str { "Link" }
+	fn previous(&self) -> Option<&'static str> { Some("Link") }
 
 	fn regexes(&self) -> &[Regex] { &self.re }
 

src/elements/list.rs

@@ -106,6 +106,7 @@ impl ContainerElement for ListEntry {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ListRule {
 	start_re: Regex,
 	continue_re: Regex,
@@ -249,6 +250,7 @@ impl ListRule {
 
 impl Rule for ListRule {
 	fn name(&self) -> &'static str { "List" }
+	fn previous(&self) -> Option<&'static str> { Some("Raw") }
 
 	fn next_match(&self, _state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
 		self.start_re

src/elements/media.rs

@@ -221,6 +221,7 @@ impl ReferenceableElement for Medium {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct MediaRule {
 	re: [Regex; 1],
 	properties: PropertyParser,
@@ -325,6 +326,7 @@ impl MediaRule {
 
 impl RegexRule for MediaRule {
 	fn name(&self) -> &'static str { "Media" }
+	fn previous(&self) -> Option<&'static str> { Some("Graph") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/mod.rs

@@ -9,7 +9,6 @@ pub mod media;
 pub mod paragraph;
 pub mod raw;
 pub mod reference;
-pub mod registrar;
 pub mod script;
 pub mod section;
 pub mod style;

src/elements/paragraph.rs

@@ -91,6 +91,7 @@ impl ContainerElement for Paragraph {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ParagraphRule {
 	re: Regex,
 }
@@ -104,7 +105,8 @@ impl ParagraphRule {
 }
 
 impl Rule for ParagraphRule {
-	fn name(&self) -> &'static str { "Paragraphing" }
+	fn name(&self) -> &'static str { "Paragraph" }
+	fn previous(&self) -> Option<&'static str> { Some("Comment") }
 
 	fn next_match(&self, _state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
 		self.re

src/elements/raw.rs

@@ -44,6 +44,7 @@ impl Element for Raw {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct RawRule {
 	re: [Regex; 1],
 	properties: PropertyParser,
@@ -72,6 +73,7 @@ impl RawRule {
 
 impl RegexRule for RawRule {
 	fn name(&self) -> &'static str { "Raw" }
+	fn previous(&self) -> Option<&'static str> { Some("Variable Substitution") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/reference.rs

@@ -62,6 +62,7 @@ impl Element for Reference {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ReferenceRule {
 	re: [Regex; 1],
 	properties: PropertyParser,
@@ -127,6 +128,7 @@ impl ReferenceRule {
 
 impl RegexRule for ReferenceRule {
 	fn name(&self) -> &'static str { "Reference" }
+	fn previous(&self) -> Option<&'static str> { Some("Text") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/registrar.rs

@@ -1,46 +0,0 @@
-use crate::parser::parser::Parser;
-
-use super::code::CodeRule;
-use super::comment::CommentRule;
-use super::elemstyle::ElemStyleRule;
-use super::graphviz::GraphRule;
-use super::import::ImportRule;
-use super::layout::LayoutRule;
-use super::link::LinkRule;
-use super::list::ListRule;
-use super::media::MediaRule;
-use super::paragraph::ParagraphRule;
-use super::raw::RawRule;
-use super::script::ScriptRule;
-use super::section::SectionRule;
-use super::style::StyleRule;
-use super::customstyle::CustomStyleRule;
-use super::tex::TexRule;
-use super::text::TextRule;
-use super::variable::VariableRule;
-use super::variable::VariableSubstitutionRule;
-use super::reference::ReferenceRule;
-
-pub fn register<P: Parser>(parser: &mut P) {
-	parser.add_rule(Box::new(CommentRule::new()), None).unwrap();
-	parser.add_rule(Box::new(ParagraphRule::new()), None).unwrap();
-	parser.add_rule(Box::new(ImportRule::new()), None).unwrap();
-	parser.add_rule(Box::new(ScriptRule::new()), None).unwrap();
-	parser.add_rule(Box::new(ElemStyleRule::new()), None).unwrap();
-	parser.add_rule(Box::new(VariableRule::new()), None).unwrap();
-	parser.add_rule(Box::new(VariableSubstitutionRule::new()), None).unwrap();
-	parser.add_rule(Box::new(RawRule::new()), None).unwrap();
-	parser.add_rule(Box::new(ListRule::new()), None).unwrap();
-	parser.add_rule(Box::new(CodeRule::new()), None).unwrap();
-	parser.add_rule(Box::new(TexRule::new()), None).unwrap();
-	parser.add_rule(Box::new(GraphRule::new()), None).unwrap();
-	parser.add_rule(Box::new(MediaRule::new()), None).unwrap();
-	parser.add_rule(Box::new(LayoutRule::new()), None).unwrap();
-
-	parser.add_rule(Box::new(StyleRule::new()), None).unwrap();
-	parser.add_rule(Box::new(CustomStyleRule{}), None).unwrap();
-	parser.add_rule(Box::new(SectionRule::new()), None).unwrap();
-	parser.add_rule(Box::new(LinkRule::new()), None).unwrap();
-	parser.add_rule(Box::new(TextRule::default()), None).unwrap();
-	parser.add_rule(Box::new(ReferenceRule::new()), None).unwrap();
-}

src/elements/script.rs

@@ -20,6 +20,7 @@ use std::rc::Rc;
 
 use super::text::Text;
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct ScriptRule {
 	re: [Regex; 2],
 	eval_kinds: [(&'static str, &'static str); 3],
@@ -77,6 +78,7 @@ impl ScriptRule {
 
 impl RegexRule for ScriptRule {
 	fn name(&self) -> &'static str { "Script" }
+	fn previous(&self) -> Option<&'static str> { Some("Import") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/section.rs

@@ -135,6 +135,7 @@ impl ReferenceableElement for Section {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct SectionRule {
 	re: [Regex; 1],
 }
@@ -155,6 +156,7 @@ pub mod section_kind {
 
 impl RegexRule for SectionRule {
 	fn name(&self) -> &'static str { "Section" }
+	fn previous(&self) -> Option<&'static str> { Some("Custom Style") }
 
 	fn regexes(&self) -> &[Regex] { &self.re }
 

src/elements/style.rs

@@ -132,6 +132,7 @@ impl RuleState for StyleState {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct StyleRule {
 	re: [Regex; 4],
 }
@@ -157,6 +158,7 @@ static STATE_NAME: &'static str = "elements.style";
 
 impl RegexRule for StyleRule {
 	fn name(&self) -> &'static str { "Style" }
+	fn previous(&self) -> Option<&'static str> { Some("Layout") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/tex.rs

@@ -219,6 +219,7 @@ impl Element for Tex {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct TexRule {
 	re: [Regex; 2],
 	properties: PropertyParser,
@@ -296,6 +297,7 @@ impl TexRule {
 
 impl RegexRule for TexRule {
 	fn name(&self) -> &'static str { "Tex" }
+	fn previous(&self) -> Option<&'static str> { Some("Code") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/elements/text.rs

@@ -42,13 +42,20 @@ impl Element for Text {
 	}
 }
 
-#[derive(Default)]
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct TextRule;
 
+impl TextRule {
+	pub fn new() -> Self { Self {} }
+}
+
 impl Rule for TextRule {
 	fn name(&self) -> &'static str { "Text" }
+	fn previous(&self) -> Option<&'static str> { Some("Link") }
 
-	fn next_match(&self, _state: &ParserState, _cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> { None }
+	fn next_match(&self, _state: &ParserState, _cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
+		None
+	}
 
 	fn on_match(
 		&self,

src/elements/variable.rs

@@ -37,6 +37,7 @@ impl FromStr for VariableKind {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct VariableRule {
 	re: [Regex; 1],
 	kinds: Vec<(String, String)>,
@@ -117,6 +118,7 @@ impl VariableRule {
 
 impl RegexRule for VariableRule {
 	fn name(&self) -> &'static str { "Variable" }
+	fn previous(&self) -> Option<&'static str> { Some("Element Style") }
 
 	fn regexes(&self) -> &[Regex] { &self.re }
 
@@ -295,6 +297,7 @@ impl RegexRule for VariableRule {
 	}
 }
 
+#[auto_registry::auto_registry(registry = "rules")]
 pub struct VariableSubstitutionRule {
 	re: [Regex; 1],
 }
@@ -309,6 +312,7 @@ impl VariableSubstitutionRule {
 
 impl RegexRule for VariableSubstitutionRule {
 	fn name(&self) -> &'static str { "Variable Substitution" }
+	fn previous(&self) -> Option<&'static str> { Some("Variable") }
 
 	fn regexes(&self) -> &[regex::Regex] { &self.re }
 

src/parser/langparser.rs

@@ -4,7 +4,6 @@ use std::rc::Rc;
 use crate::document::document::Document;
 use crate::document::element::DocumentEnd;
 use crate::document::langdocument::LangDocument;
-use crate::elements::registrar::register;
 use crate::elements::text::Text;
 
 use super::parser::Parser;
@@ -35,8 +34,10 @@ impl LangParser {
 		};
 
 		// Register rules
-		// TODO: use https://docs.rs/inventory/latest/inventory/
+		for rule in super::rule::get_rule_registry()
-		register(&mut s);
+		{
+			s.add_rule(rule).unwrap();
+		}
 
 		s
 	}

src/parser/parser.rs

@@ -19,7 +19,6 @@ use crate::document::document::DocumentAccessors;
 use crate::document::element::ContainerElement;
 use crate::document::element::ElemKind;
 use crate::document::element::Element;
-use crate::elements::customstyle::CustomStyleRule;
 use crate::elements::paragraph::Paragraph;
 use crate::lua::kernel::Kernel;
 use crate::lua::kernel::KernelHolder;
@@ -186,7 +185,6 @@ impl<'a, 'b> ParserState<'a, 'b> {
 			.for_each(|(rule, (matched_at, match_data))| {
 				// Don't upate if not stepped over yet
 				if *matched_at > cursor.pos {
-					// TODO: maybe we should expose matches() so it becomes possible to dynamically register a new rule
 					return;
 				}
 
@@ -369,7 +367,7 @@ pub trait Parser {
 	/// # Warning
 	///
 	/// This method must not be called if a [`ParserState`] for this parser exists.
-	fn add_rule(&mut self, rule: Box<dyn Rule>, after: Option<&'static str>) -> Result<(), String> {
+	fn add_rule(&mut self, rule: Box<dyn Rule>) -> Result<(), String> {
 		if let Some(_) = self
 			.rules()
 			.iter()
@@ -381,23 +379,7 @@ pub trait Parser {
 			));
 		}
 
-		// Try to insert after
-		if let Some(after) = after {
-			let index = self
-				.rules()
-				.iter()
-				.enumerate()
-				.find(|(_, rule)| rule.name() == after)
-				.map(|(idx, _)| idx);
-
-			if let Some(index) = index {
-				self.rules_mut().insert(index, rule);
-			} else {
-				return Err(format!("Unable to find rule `{after}` to insert after"));
-			}
-		} else {
 		self.rules_mut().push(rule);
-		}
 
 		Ok(())
 	}

src/parser/rule.rs

@@ -12,12 +12,66 @@ use mlua::Function;
 use mlua::Lua;
 
 use std::any::Any;
+use std::collections::HashMap;
 use std::ops::Range;
 use std::rc::Rc;
 
+macro_rules! create_registry {
+	( $($construct:expr),+ $(,)? ) => {{
+		let mut map = HashMap::new();
+		$(
+			let boxed = Box::new($construct) as Box<dyn Rule>;
+			map.insert(boxed.name(), boxed);
+		)+
+		map
+	}};
+}
+
+/// Gets the list of all rules exported with the [`auto_registry`] proc macro.
+/// Rules are sorted according to topological order using the [`Rule::previous`] method.
+#[auto_registry::generate_registry(registry = "rules", target = make_rules, return_type = HashMap<&'static str, Box<dyn Rule>>, maker = create_registry)]
+pub fn get_rule_registry() -> Vec<Box<dyn Rule>> {
+	fn cmp(
+		map: &HashMap<&'static str, Box<dyn Rule>>,
+		lname: &'static str,
+		rname: &'static str,
+	) -> std::cmp::Ordering {
+		let l = map.get(lname).unwrap();
+		let r = map.get(rname).unwrap();
+		if l.previous() == Some(r.name()) {
+			std::cmp::Ordering::Greater
+		} else if r.previous() == Some(l.name()) {
+			std::cmp::Ordering::Less
+		} else if l.previous().is_some() && r.previous().is_none() {
+			std::cmp::Ordering::Greater
+		} else if r.previous().is_some() && l.previous().is_none() {
+			std::cmp::Ordering::Less
+		} else if let (Some(pl), Some(pr)) = (l.previous(), r.previous()) {
+			cmp(map, pl, pr)
+		} else {
+			std::cmp::Ordering::Equal
+		}
+	}
+	let mut map = make_rules();
+	let mut sorted_keys = map.iter().map(|(key, _)| *key).collect::<Vec<_>>();
+	sorted_keys.sort_by(|l, r| cmp(&map, l, r));
+
+	let mut owned = Vec::with_capacity(sorted_keys.len());
+	for key in sorted_keys {
+		let rule = map.remove(key).unwrap();
+		owned.push(rule);
+	}
+
+	owned
+}
+
 pub trait Rule: Downcast {
-	/// Returns rule's name
+	/// The rule name
 	fn name(&self) -> &'static str;
+
+	/// The name of the rule that should come before this one
+	fn previous(&self) -> Option<&'static str>;
+
 	/// Finds the next match starting from [`cursor`]
 	fn next_match(&self, state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)>;
 	/// Callback when rule matches
@@ -47,8 +101,12 @@ impl core::fmt::Debug for dyn Rule {
 }
 
 pub trait RegexRule {
+	/// The rule name
 	fn name(&self) -> &'static str;
 
+	/// The name of the rule that should come before this one
+	fn previous(&self) -> Option<&'static str>;
+
 	/// Returns the rule's regexes
 	fn regexes(&self) -> &[regex::Regex];
 
@@ -69,6 +127,7 @@ pub trait RegexRule {
 
 impl<T: RegexRule + 'static> Rule for T {
 	fn name(&self) -> &'static str { RegexRule::name(self) }
+	fn previous(&self) -> Option<&'static str> { RegexRule::previous(self) }
 
 	/// Finds the next match starting from [`cursor`]
 	fn next_match(&self, _state: &ParserState, cursor: &Cursor) -> Option<(usize, Box<dyn Any>)> {
@@ -120,3 +179,41 @@ impl<T: RegexRule + 'static> Rule for T {
 
 	fn register_layouts(&self, holder: &mut LayoutHolder) { self.register_layouts(holder); }
 }
+
+#[cfg(test)]
+mod tests {
+
+	use super::*;
+
+	#[test]
+	fn registry() {
+		let rules = get_rule_registry();
+		let names: Vec<&'static str> = rules.iter().map(|rule| rule.name()).collect();
+
+		assert_eq!(
+			names,
+			vec![
+				"Comment",
+				"Paragraph",
+				"Import",
+				"Script",
+				"Element Style",
+				"Variable",
+				"Variable Substitution",
+				"Raw",
+				"List",
+				"Code",
+				"Tex",
+				"Graph",
+				"Media",
+				"Layout",
+				"Style",
+				"Custom Style",
+				"Section",
+				"Link",
+				"Text",
+				"Reference",
+			]
+		);
+	}
+}