Symbol Aliases

build.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::fmt::Write;
 use std::iter::Peekable;
 use std::path::Path;
@@ -30,6 +31,7 @@ enum Def<'a> {
 enum Symbol<'a> {
     Single(char),
     Multi(Vec<(&'a str, char)>),
+    MultiAlias(Vec<(Cow<'a, str>, char)>),
 }
 
 /// A single line during parsing.
@@ -41,6 +43,7 @@ enum Line<'a> {
     ModuleEnd,
     Symbol(&'a str, Option<char>),
     Variant(&'a str, char),
+    Alias(&'a str, &'a str, &'a str, bool),
 }
 
 fn main() {
@@ -111,6 +114,23 @@ fn tokenize(line: &str) -> StrResult<Line> {
         }
         let c = decode_char(tail.ok_or("missing char")?)?;
         Line::Variant(rest, c)
+    } else if let Some(mut value) = tail.and_then(|tail| tail.strip_prefix("@= ")) {
+        let alias = head;
+        validate_ident(alias)?;
+        let mut deep = false;
+        if let Some(v) = value.strip_suffix(".*") {
+            deep = true;
+            value = v;
+        }
+        let (head, rest) = value.split_once('.').unwrap_or((value, ""));
+        validate_ident(head)?;
+        if !rest.is_empty() {
+            for part in rest.split('.') {
+                validate_ident(part)?;
+            }
+        }
+
+        Line::Alias(alias, head, rest, deep)
     } else {
         validate_ident(head)?;
         let c = tail.map(decode_char).transpose()?;
@@ -149,6 +169,7 @@ fn parse<'a>(
 ) -> StrResult<Vec<(&'a str, Binding<'a>)>> {
     let mut defs = vec![];
     let mut deprecation = None;
+    let mut aliases = vec![];
     loop {
         match p.next().transpose()? {
             None | Some(Line::ModuleEnd) => {
@@ -158,6 +179,10 @@ fn parse<'a>(
                 break;
             }
             Some(Line::Deprecated(message)) => deprecation = Some(message),
+            Some(Line::Alias(alias, name, variant, deep)) => {
+                aliases.push((alias, name, variant, deep, deprecation));
+                deprecation = None;
+            }
             Some(Line::Symbol(name, c)) => {
                 let mut variants = vec![];
                 while let Some(Line::Variant(name, c)) = p.peek().cloned().transpose()? {
@@ -192,6 +217,95 @@ fn parse<'a>(
             other => return Err(format!("expected definition, found {other:?}")),
         }
     }
+    for (alias, name, variant, deep, deprecation) in aliases {
+        let aliased_symbol: &Symbol<'a> = defs
+            .iter()
+            .filter(|(n, _)| *n == name)
+            .find_map(|(_, b)| match &b.def {
+                Def::Symbol(s) => Some(s),
+                _ => None,
+            })
+            .ok_or_else(|| format!("alias to nonexistent symbol: {name}"))?;
+
+        match aliased_symbol {
+            &Symbol::Single(c) => {
+                if variant != "" {
+                    return Err(format!(
+                        "alias to nonexistent variant: {name}.{variant}"
+                    ));
+                }
+                defs.push((
+                    alias,
+                    Binding { def: Def::Symbol(Symbol::Single(c)), deprecation },
+                ));
+            }
+            Symbol::MultiAlias(_) => {
+                return Err(format!("alias to alias: {name}.{variant}"));
+            }
+            Symbol::Multi(variants) => {
+                let variants: Vec<(Cow<'a, str>, char)> = variants
+                    .iter()
+                    .filter_map(|&(var, c)| {
+                        if var == variant {
+                            Some((Cow::Borrowed(""), c))
+                        } else if deep {
+                            var.strip_prefix(variant)?
+                                .strip_prefix('.')
+                                .map(|v| (Cow::Borrowed(v), c))
+                                .or_else(|| {
+                                    // might just be in a different order
+
+                                    let mut alias_modifs = if variant.is_empty() {
+                                        vec![]
+                                    } else {
+                                        variant.split('.').collect()
+                                    };
+
+                                    let mut new_variant = Cow::Borrowed("");
+                                    for modif in var.split('.') {
+                                        if let Some(i) =
+                                            alias_modifs.iter().position(|m| *m == modif)
+                                        {
+                                            alias_modifs.swap_remove(i);
+                                        } else if new_variant.is_empty() {
+                                            new_variant = Cow::Borrowed(modif);
+                                        } else {
+                                            new_variant = Cow::Owned(format!(
+                                                "{new_variant}.{modif}"
+                                            ));
+                                        }
+                                    }
+                                    alias_modifs.is_empty().then_some((new_variant, c))
+                                })
+                        } else {
+                            None
+                        }
+                    })
+                    .collect();
+                if variants.is_empty() {
+                    return Err(format!(
+                        "alias to nonexistent variant: {name}.{variant}"
+                    ));
+                }
+                if let [(ref s, c)] = variants[..] {
+                    if s.is_empty() {
+                        defs.push((
+                            alias,
+                            Binding { def: Def::Symbol(Symbol::Single(c)), deprecation },
+                        ));
+                        continue;
+                    }
+                }
+                defs.push((
+                    alias,
+                    Binding {
+                        def: Def::Symbol(Symbol::MultiAlias(variants)),
+                        deprecation,
+                    },
+                ));
+            }
+        }
+    }
     Ok(defs)
 }
 
@@ -211,6 +325,7 @@ fn encode(buf: &mut String, module: &Module) {
                 match symbol {
                     Symbol::Single(c) => write!(buf, "Single({c:?})").unwrap(),
                     Symbol::Multi(list) => write!(buf, "Multi(&{list:?})").unwrap(),
+                    Symbol::MultiAlias(list) => write!(buf, "Multi(&{list:?})").unwrap(),
                 }
                 buf.push_str(")");
             }

src/modules/sym.txt

@@ -199,7 +199,7 @@ breve ˘
 caret ‸
 caron ˇ
 hat ^
-diaer ¨
+diaer @= dot.double
 grave `
 macron ¯
 quote
@@ -365,8 +365,7 @@ succ ≻
   .not ⊁
   .ntilde ⋩
   .tilde ≿
-equiv ≡
-  .not ≢
+equiv @= eq.triple.*
 smt ⪪
   .eq ⪬
 lat ⪫
@@ -384,12 +383,7 @@ emptyset ∅
   .bar ⦱
   .circle ⦲
   .rev ⦰
-nothing ∅
-  .arrow.r ⦳
-  .arrow.l ⦴
-  .bar ⦱
-  .circle ⦲
-  .rev ⦰
+nothing @= emptyset.*
 without ∖
 complement ∁
 in ∈
@@ -447,11 +441,11 @@ infinity ∞
   .bar ⧞
   .incomplete ⧜
   .tie ⧝
-oo ∞
-diff ∂
+oo @= infinity
+diff @= partial.*
 partial ∂
 gradient ∇
-nabla ∇
+nabla @= gradient.*
 sum ∑
   .integral ⨋
 product ∏
@@ -481,8 +475,8 @@ laplace ∆
 forall ∀
 exists ∃
   .not ∄
-top ⊤
-bot ⊥
+top @= tack.b
+bot @= tack.t
 not ¬
 and ∧
   .big ⋀
@@ -494,8 +488,7 @@ or ∨
   .curly ⋎
   .dot ⟇
   .double ⩔
-xor ⊕
-  .big ⨁
+xor @= plus.circle.*
 models ⊧
 forces ⊩
   .not ⊮
@@ -504,10 +497,9 @@ because ∵
 qed ∎
 
 // Function and category theory.
-mapsto ↦
-  .long ⟼
-compose ∘
-convolve ∗
+mapsto @= arrow.r.bar.*
+compose @= circle.stroked.tiny
+convolve @= ast.op
 multimap ⊸
   .double ⧟
 
@@ -999,13 +991,13 @@ Zeta Ζ
 // from Letterlike Symbols.
 // See https://github.com/typst/typst/pull/3375.
 aleph א
-alef א
+alef @= aleph
 beth ב
-bet ב
+bet @= beth
 gimmel ג
-gimel ג
+gimel @= gimmel
 daleth ד
-dalet ד
+dalet @= daleth
 shin ש
 
 // Double-struck.