Module pprint 

AST → .polydat source pretty-printer.

The printer gives a compiled for body its source text for diagnostics (pp_file), re-emits rewritten expressions in module inlining and tile lowering (pp_expr), and prints expressions in polydat explain. The runtime compiles from the AST; the printer is a faithful AST → source round-trip beside it.

Round-trip contract

For every Statement/Expr produced by the parser, pp_statement / pp_expr produces source text that re-parses into a semantically equivalent AST. “Semantically equivalent” means same node types and identical inner data (modulo Spans, which capture parser position and are not preserved across re-parse).

Precedence and parens

BinOp expressions are emitted with parens around the whole expression. This is uniformly safe — re-parsing produces the same tree structure — at the cost of extra parens. The output is the canonical spelling; the parens are uniform for round-trip safety.

Functions

pp_expr

Pretty-print an expression. Always emits parens around BinOp for round-trip safety.

pp_file

Pretty-print a full file: every statement, separated by newlines.

pp_statement

Pretty-print a top-level statement.