working vm: parser, admission with totality checks, solver and repl

2 files changed, 21 insertions, 0 deletions

diff --git a/lib/front.ml b/lib/front.ml
new file mode 100644
index 0000000..7cacc20
--- /dev/null
+++ b/lib/front.ml
@@ -0,0 +1,14 @@
+let parse_string source =
+  let lexbuf = Lexing.from_string source in
+  match Parser.program Lexer.token lexbuf with
+  | statements -> Ok statements
+  | exception Lexer.Error message ->
+      let position = lexbuf.Lexing.lex_curr_p in
+      Error
+        (Printf.sprintf "lexical error at line %d: %s"
+           position.Lexing.pos_lnum message)
+  | exception Parser.Error ->
+      let position = lexbuf.Lexing.lex_curr_p in
+      Error
+        (Printf.sprintf "syntax error at line %d, before %S"
+           position.Lexing.pos_lnum (Lexing.lexeme lexbuf))
diff --git a/lib/front.mli b/lib/front.mli
new file mode 100644
index 0000000..00fa65f
--- /dev/null
+++ b/lib/front.mli
@@ -0,0 +1,7 @@
+(** Front door: text to statements.
+
+    Wraps the generated lexer and parser so callers see one total
+    function from source text to syntax or a positioned message.
+    The REPL, the file runner, and the tests all enter here. *)
+
+val parse_string : string -> (Ast.statement list, string) result