[assembler] Support super/subscript multiplication sign (×).

Author: youngman-g

assembler/src/asmlib/lexer.rs

@@ -128,7 +128,7 @@ pub(crate) enum Token {
     // @plus@ is actually not the correct glyph name, following sub.py.
     Plus(Script),
     Minus(Script),
-    Times,
+    Times(Script),
     LogicalOr(Script),
     LogicalAnd(Script),
 
@@ -194,7 +194,7 @@ impl Display for Token {
             Token::Solidus(script) => write_elevated(script, "/"),
             Token::Plus(script) => write_elevated(script, "+"),
             Token::Minus(script) => write_elevated(script, "-"),
-            Token::Times => f.write_char('×'),
+            Token::Times(script) => write_elevated(script, "×"),
             Token::LogicalOr(script) => write_elevated(script, "∨"),
             Token::LogicalAnd(script) => write_elevated(script, "∧"),
             Token::Digits(script, numeric_literal) => {
@@ -493,7 +493,7 @@ mod lexer_impl_new {
                 todo!("double-pipe (which is a symex terminator) does not yet have a token")
             }
             GlyphShape::Solidus => Some(Token::Solidus(script)),
-            GlyphShape::Times => only_normal(Token::Times),
+            GlyphShape::Times => Some(Token::Times(script)),
             GlyphShape::Hash => Some(Token::Hash(script)),
             GlyphShape::Arrow => Some(match script {
                 Script::Super | Script::Sub => unimplemented!(),

assembler/src/asmlib/lexer/tests.rs

@@ -976,8 +976,22 @@ fn test_solidus() {
 
 #[test]
 fn test_times() {
-    assert_eq!(scan_tokens_only("×"), Ok(vec![Token::Times,]));
-    assert_eq!(scan_tokens_only("@times@"), Ok(vec![Token::Times,]));
+    assert_eq!(
+        scan_tokens_only("×"),
+        Ok(vec![Token::Times(Script::Normal),])
+    );
+    assert_eq!(
+        scan_tokens_only("@times@"),
+        Ok(vec![Token::Times(Script::Normal),])
+    );
+    assert_eq!(
+        scan_tokens_only("@sup_times@"),
+        Ok(vec![Token::Times(Script::Super),])
+    );
+    assert_eq!(
+        scan_tokens_only("@sub_times@"),
+        Ok(vec![Token::Times(Script::Sub),])
+    );
 }
 
 #[test]

assembler/src/asmlib/parser.rs

@@ -203,8 +203,7 @@ where
         // "Word Assembly" for details.
         Tok::Solidus(script) if script_required == script => Operator::Divide,
         Tok::Plus(Script::Normal) => Operator::Add,
-        // TODO: support subscript/superscript for times
-        Tok::Times if script_required == Script::Normal => Operator::Multiply,
+        Tok::Times(got) if got == script_required => Operator::Multiply,
         Tok::LogicalOr(got) if got == script_required => Operator::LogicalOr,
         Tok::LogicalAnd(got) if got == script_required => Operator::LogicalAnd,
         Tok::Minus(got) if script_required == got => Operator::Subtract,
@@ -324,7 +323,7 @@ where
         just(Tok::Intersection).to('∩'),
         just(Tok::Union).to('∪'),
         just(Tok::Solidus(Script::Normal)).to('/'),
-        just(Tok::Times).to('×'),
+        just(Tok::Times(Script::Normal)).to('×'),
         just(Tok::LogicalOr(Script::Normal)).to('∨'),
         just(Tok::LogicalAnd(Script::Normal)).to('∧'),
     ))