dartLangSpec-3515.pdf

Based on the output from git diff main..., here is an overview of the changes:

Front matter

Only comments.

@@ -21633,128 +21631,188 @@

Section 'Subtypes': Now mentions intersection types.

Figure 'Subtype rules': Changed a lot.

Subsection 'Meta-Variables': Slightly changes presentation of
metavariables.

Subsection 'Subtype Rules': Introduces the 'canonical syntax' of a
type. Controversial! An alternative could be to say that subtype rules
are not applicable to syntax, they are applicable to semantic
entities that are normalized in the same way as canonical syntax does
it. Extensively rewritten.

Subsection 'Being a Subtype': Extensively rewritten.

Subsubsection 'Informal subtype rule descriptions': Rewritten extensively.

Subsection 'Additional Subtyping Concepts': Extensively rewritten.

Section 'Function Types': Last paragraph modified.

Section 'Type Function': Rewritten.

@@ -22482,7 +22498,7 @@

Just the title of section 'Type dynamic' was adjusted, for consistency
(that is: titles do not use non-standard fonts).

Section 'Type FutureOr': Just adding missing \Error{} on static
errors, and updating Object to Object? in an example.

Section 'Type void': Removed commentary that reiterated an obsolete
definition of Type equality. Removed the item that enabled await expressionOfTypeVoid, because that rule that enabled this usage has
been removed from the language. Example at the end is updated.

Subsection 'Void Soundness': Example updated, plus body text about the
example.

@@ -23324,156 +23324,238 @@

Section 'Appendix: Algorithmic Subtyping': Updated to use the
NNBD-updated presentation of the subtype rules.

I tried to use latexdiff to generate a PDF that shows the differences, but it doesn't handle "non-standard" LaTeX (which seems to be difficult to avoid). I can generate a PDF that shows some differences and stops at page 232, but it would take some more experimentation to produce something that shows the differences in a way that can be relied upon.

I added a section about 'being the same type', and adjusted the text such that the thing previously known as 'canonical syntax' (now renamed to 'explicitly resolved syntax') is encapsulated in this section. Also, alpha equivalence has been made part of this 'being the same type' section.