unison/unison-src/transcripts/fix2840.md

This bugfix addresses an issue where embedded Unison code in UCM was expected to be present in the active codebase when the display command was used render Doc values.

scratch/main> builtins.merge

First, a few [hidden] definitions necessary for typechecking a simple Doc2.

structural type Optional a = None | Some a

unique[b7a4fb87e34569319591130bf3ec6e24c9955b6a] type Doc2
  = Word Text
  | Code Doc2
  | CodeBlock Text Doc2
  | Bold Doc2
  | Italic Doc2
  | Strikethrough Doc2
  | Style Text Doc2
  | Anchor Text Doc2
  | Blockquote Doc2
  | Blankline
  | Linebreak
  | SectionBreak
  | Tooltip Doc2 Doc2
  | Aside Doc2
  | Callout (Optional Doc2) Doc2
  | Table [[Doc2]]
  | Folded Boolean Doc2 Doc2
  | Paragraph [Doc2]
  | BulletedList [Doc2]
  | NumberedList Nat [Doc2]
  | Section Doc2 [Doc2]
  | NamedLink Doc2 Doc2
  | Image Doc2 Doc2 (Optional Doc2)
  | Special Doc2.SpecialForm
  | Join [Doc2]
  | UntitledSection [Doc2]
  | Column [Doc2]
  | Group Doc2

unique[da70bff6431da17fa515f3d18ded11852b6a745f] type Doc2.SpecialForm
  = Source [(Either Link.Type Doc2.Term, [Doc2.Term])]
  | FoldedSource [(Either Link.Type Doc2.Term, [Doc2.Term])]
  | Example Nat Doc2.Term
  | ExampleBlock Nat Doc2.Term
  | Link (Either Link.Type Doc2.Term)
  | Signature [Doc2.Term]
  | SignatureInline Doc2.Term
  | Eval Doc2.Term
  | EvalInline Doc2.Term
  | Embed Any
  | EmbedInline Any

-- A newtype used when embedding term references in a Doc2
unique[fb488e55e66e2492c2946388e4e846450701db04] type Doc2.Term = Term Any

syntax.docUntitledSection = cases
  [d] -> d
  ds -> UntitledSection ds
syntax.docParagraph = Paragraph
syntax.docWord = Word

scratch/main> add

Next, define and display a simple Doc:

README = {{
Hi
}}

scratch/main> display README

Previously, the error was:

⚙️   Processing stanza 5 of 7.ucm: PE [("die",SrcLoc {srcLocPackage = "unison-parser-typechecker-0.0.0-He2Hp1llokT2nN4MnUfUXz", srcLocModule = "Unison.Runtime.Interface", srcLocFile = "src/Unison/Runtime/Interface.hs", srcLocStartLine = 118, srcLocStartCol = 18, srcLocEndLine = 118, srcLocEndCol = 60})] Lit
  AnnotatedText (fromList [Segment {segment = "Unknown term reference: #4522d", annotation = Nothing}])

but as of this PR, it's okay.