Files
rose-ash/hosts/ocaml/bin/test_cst.ml
giles 5390df7b0b CST parser: lossless concrete syntax tree for .sx files
New sx_cst.ml: CstAtom, CstList, CstDict node types with leading/trailing
trivia (whitespace + comments). Two projections:
- cst_to_source/cst_file_to_source: exact source reconstruction
- cst_to_ast: strip trivia → Sx_types.value for evaluation

New parse_all_cst/parse_file_cst in sx_parser.ml: parallel CST parser
alongside existing AST parser. Reuses read_string, read_symbol, try_number.
Trivia collected via collect_trivia (replaces skip_whitespace_and_comments).

Round-trip invariant: cst_file_to_source(parse_all_cst(src)) = src
Verified on 13 synthetic tests + 7 real codebase files (101KB evaluator,
parser, primitives, render, tree-tools, engine, io).

CST→AST equivalence: cst_to_ast matches parse_all output.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-03 18:07:35 +00:00

92 lines
3.2 KiB
OCaml

let () =
let test_sources = [
"(define foo 42)";
";; comment\n(define bar 1)\n\n;; another\n(define baz 2)\n";
"(define my-fn\n (fn (x)\n ;; check nil\n (if (nil? x) 0 x)))";
"(list 1 2 3)";
"{:key \"value\" :num 42}";
"'(a b c)";
"`(a ,b ,@c)";
"(define x \"hello\\nworld\")";
";; top\n;; multi-line\n(define a 1)\n";
"";
" \n ";
"(a)\n(b)\n(c)";
"(a ;; inline\n b)";
] in
let pass = ref 0 in
let fail = ref 0 in
List.iter (fun src ->
let cst = Sx_parser.parse_all_cst src in
let roundtrip = Sx_cst.cst_file_to_source cst.nodes cst.trailing_trivia in
if roundtrip = src then begin
incr pass;
Printf.printf "PASS: %S\n" (if String.length src > 40 then String.sub src 0 40 ^ "..." else src)
end else begin
incr fail;
Printf.printf "FAIL: %S\n expected: %S\n got: %S\n"
(if String.length src > 40 then String.sub src 0 40 ^ "..." else src)
src roundtrip
end
) test_sources;
(* Also test CST→AST matches AST parser *)
let ast_tests = [
"(define foo 42)";
"(list 1 2 3)";
"{:key \"value\"}";
";; comment\n(define bar 1)";
] in
Printf.printf "\nCST→AST equivalence:\n";
List.iter (fun src ->
let ast_direct = Sx_parser.parse_all src in
let cst = Sx_parser.parse_all_cst src in
let ast_via_cst = List.map Sx_cst.cst_to_ast cst.nodes in
let s1 = String.concat " " (List.map Sx_types.inspect ast_direct) in
let s2 = String.concat " " (List.map Sx_types.inspect ast_via_cst) in
if s1 = s2 then begin
incr pass;
Printf.printf "PASS: %S\n" src
end else begin
incr fail;
Printf.printf "FAIL: %S\n AST: %s\n CST→AST: %s\n" src s1 s2
end
) ast_tests;
(* Test real .sx files from the codebase *)
Printf.printf "\nReal file round-trips:\n";
let test_file path =
try
let src = In_channel.with_open_text path In_channel.input_all in
let cst = Sx_parser.parse_all_cst src in
let roundtrip = Sx_cst.cst_file_to_source cst.nodes cst.trailing_trivia in
if roundtrip = src then begin
incr pass;
Printf.printf "PASS: %s (%d bytes)\n" path (String.length src)
end else begin
incr fail;
(* Find first difference *)
let len = min (String.length src) (String.length roundtrip) in
let diff_pos = ref len in
for i = 0 to len - 1 do
if src.[i] <> roundtrip.[i] && !diff_pos = len then diff_pos := i
done;
Printf.printf "FAIL: %s (diff at byte %d, src=%d rt=%d)\n" path !diff_pos (String.length src) (String.length roundtrip)
end
with e ->
incr fail;
Printf.printf "ERROR: %s — %s\n" path (Printexc.to_string e)
in
let spec_dir = try Sys.getenv "SX_SPEC_DIR" with Not_found -> "spec" in
let project_dir = try Sys.getenv "SX_PROJECT_DIR" with Not_found -> "." in
List.iter test_file [
spec_dir ^ "/evaluator.sx";
spec_dir ^ "/parser.sx";
spec_dir ^ "/primitives.sx";
spec_dir ^ "/render.sx";
project_dir ^ "/lib/tree-tools.sx";
project_dir ^ "/web/engine.sx";
project_dir ^ "/web/io.sx";
];
Printf.printf "\n%d/%d passed\n" !pass (!pass + !fail);
if !fail > 0 then exit 1