Two-phase grammar: parse-expr-no-seq (prior entry) + parse-expr wraps
it with ;-chaining. List bodies keep parse-expr-no-seq so ; remains a
separator inside [...]. Match clause bodies use the seq variant and stop
at | — real OCaml semantics. Trailing ; before end/)/|/in/then/else/eof
permitted.
Patterns: wildcard, literal, var, ctor (nullary + arg, flattens tuple
args so Pair(a,b) -> (:pcon "Pair" PA PB)), tuple, list literal, cons
:: (right-assoc), unit. Match: leading | optional, (:match SCRUT
CLAUSES) with each clause (:case PAT BODY). Body parsed via parse-expr
because | is below level-1 binop precedence.
ocaml-parse-program: program = decls + bare exprs, ;;-separated.
Each decl is (:def …), (:def-rec …), or (:expr …). Body parsing
re-feeds the source slice through ocaml-parse — shared-state refactor
deferred.