camlp4,fix,quot: Properly handle <:patt< $`bool:p$ >>.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@8721 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 40 insertions, 0 deletions

diff --git a/camlp4/examples/lambda_quot_expr.ml b/camlp4/examples/lambda_quot_expr.ml
new file mode 100644
index 000000000..3b51f47f5
--- /dev/null
+++ b/camlp4/examples/lambda_quot_expr.ml
@@ -0,0 +1,40 @@
+(* Please keep me in sync with brion.inria.fr/gallium/index.php/Lambda_calculus_quotations *)
+
+open Camlp4.PreCast;;
+module CamlSyntax = Camlp4OCamlParser.Make(Camlp4OCamlRevisedParser.Make(Syntax));;
+
+let expr_of_string = CamlSyntax.Gram.parse_string CamlSyntax.expr_eoi;;
+
+module LambdaGram = MakeGram(Lexer);;
+
+let term = LambdaGram.Entry.mk "term";;
+let term_eoi = LambdaGram.Entry.mk "lambda term quotation";;
+
+Camlp4_config.antiquotations := true;;
+
+EXTEND LambdaGram
+  GLOBAL: term term_eoi;
+  term:
+    [ "top"
+      [ "fun"; v = var; "->"; t = term -> <:expr< `Lam($v$, $t$) >> ]
+    | "app"
+      [ t1 = SELF; t2 = SELF           -> <:expr< `App($t1$, $t2$) >> ]
+    | "simple"
+      [ `ANTIQUOT((""|"term"), a)      -> expr_of_string _loc a
+      | v = var                        -> <:expr< `Var($v$) >>
+      | "("; t = term; ")"             -> t ]
+    ];
+  var:
+    [[ v = LIDENT               -> <:expr< $str:v$ >>
+     | `ANTIQUOT((""|"var"), a) -> expr_of_string _loc a
+    ]];
+  term_eoi:
+    [[ t = term; `EOI -> t ]];
+END;;
+
+let expand_lambda_quot_expr loc _loc_name_opt quotation_contents =
+  LambdaGram.parse_string term_eoi loc quotation_contents;;
+
+Syntax.Quotation.add "lam" Syntax.Quotation.DynAst.expr_tag expand_lambda_quot_expr;;
+
+Syntax.Quotation.default := "lam";;