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[goals.git] / src / parser.mly

diff --git a/src/parser.mly b/src/parser.mly
index f058044..7146a99 100644 (file)
--- a/src/parser.mly
+++ b/src/parser.mly
@@ -18,27 +18,75 @@
  *)
 
 %{
+open Utils
 open Printf
+
+(* There are several circular dependencies between the lexer
+ * (caused by includes) and eval.  These references break
+ * the circular dependencies.  They are initialized when
+ * the program starts, hence are never really None.
+ *)
+let lexer_read = ref None
+let eval_substitute = ref None
+
+let find_on_include_path filename =
+  if not (Filename.is_implicit filename) then filename
+  else (
+    let rec loop = function
+      | [] -> filename
+      | inc :: incs ->
+         let path = inc // filename in
+         if Sys.file_exists path then path else loop incs
+    in
+    loop Cmdline.includes
+  )
+
+let do_include env loc filename optflag file =
+  let eval_substitute =
+    match !eval_substitute with None -> assert false | Some f -> f in
+  let filename = eval_substitute env loc filename in
+  let filename = find_on_include_path filename in
+  if optflag && not (Sys.file_exists filename) then env
+  else (
+    let fp = open_in filename in
+    let lexbuf = Lexing.from_channel fp in
+    lexbuf.lex_curr_p <- { lexbuf.lex_curr_p with pos_fname = filename };
+    let lexer_read =
+      match !lexer_read with None -> assert false | Some r -> r in
+    let env' = file lexer_read lexbuf in
+    close_in fp;
+    Ast.Env.merge env env'
+  )
 %}
 
 (* Tokens. *)
-%token <Ast.substs> CODE
+%token <Ast.code> CODE
 %token COLON
 %token COMMA
 %token EQUALS
 %token EOF
+%token EXPRESSION
+%token FUNCTION
 %token GOAL
 %token <string> ID
+%token INCLUDE
 %token LEFT_ARRAY
 %token LEFT_PAREN
 %token LET
+%token OPTINCLUDE
+%token PURE
+%token RETURNING
 %token RIGHT_ARRAY
 %token RIGHT_PAREN
+%token SEMICOLON
 %token <Ast.substs> STRING
+%token STRING_KEYWORD
+%token STRINGS
 %token <string> TACTIC
+%token TACTIC_KEYWORD
 
 (* Start nonterminals. *)
-%start <Ast.env> file
+%start <Ast.expr Ast.Env.t> file
 %start <Ast.expr> expr
 %%
 
@@ -47,12 +95,15 @@ file:
     ;
 
 stmts:
-    | list(stmt)
-    { List.fold_left (
-        fun env (name, expr) -> Ast.Env.add name expr env
-      ) Ast.Env.empty $1
-    }
+    | (* none *) { Ast.Env.empty }
+    | stmts INCLUDE STRING option(SEMICOLON)
+    { do_include $1 $loc $3 false file }
+    | stmts OPTINCLUDE STRING option(SEMICOLON)
+    { do_include $1 $loc $3 true file }
+    | stmts stmt option(SEMICOLON)
+    { let name, expr = $2 in Ast.Env.add name expr $1 }
     ;
+
 stmt:
     | option(goal_stmt) patterns COLON barelist option(CODE)
     { let name, params =
@@ -60,12 +111,20 @@ stmt:
         | None ->
            sprintf "_goal@%d" $startpos.pos_lnum, []
         | Some x -> x in
-      name, Ast.EGoal ($loc, (params, $2, $4, $5))
+      name, Ast.EGoalDefn ($loc, (params, $2, $4, $5))
     }
     | goal_stmt CODE
     {
       let name, params = $1 in
-      name, Ast.EGoal ($loc, (params, [], [], Some $2))
+      name, Ast.EGoalDefn ($loc, (params, [], [], Some $2))
+    }
+    | option(PURE) FUNCTION ID params_decl return_decl EQUALS CODE
+    {
+      $3, Ast.EFuncDefn ($loc, ($4, $5, $1 <> None, $7))
+    }
+    | TACTIC_KEYWORD TACTIC params_decl EQUALS CODE
+    {
+      $2, Ast.ETacticDefn ($loc, ($3, $5))
     }
     | LET ID EQUALS expr { $2, $4 }
     ;
@@ -79,13 +138,18 @@ params_decl:
     ;
 param_decl:
     | ID         { $1 }
+return_decl:
+    |            { RetExpr }
+    | RETURNING EXPRESSION { RetExpr }
+    | RETURNING STRINGS { RetStrings }
+    | RETURNING STRING_KEYWORD { RetString }
 
 patterns:
     | separated_list(COMMA, pattern) { $1 }
     ;
 pattern:
-    | STRING     { Ast.PTactic ($loc, "file", [$1]) }
-    | ID pattern_params { Ast.PTactic ($loc, $1, $2) }
+    | STRING     { Ast.PTactic ($loc, "*file", [$1]) }
+    | TACTIC pattern_params { Ast.PTactic ($loc, $1, $2) }
     ;
 pattern_params:
     | LEFT_PAREN separated_list(COMMA, pattern_param) RIGHT_PAREN { $2 }
@@ -97,13 +161,19 @@ pattern_param:
 expr:
     | ID params  { Ast.ECall ($loc, $1, $2) }
     | ID         { Ast.EVar ($loc, $1) }
-    | TACTIC params { Ast.ETactic ($loc, $1, $2) }
+    | TACTIC params { Ast.ETacticCtor ($loc, $1, $2) }
     | STRING     { Ast.ESubsts ($loc, $1) }
     | LEFT_ARRAY barelist RIGHT_ARRAY { Ast.EList ($loc, $2) }
     ;
 barelist:
-    | separated_list(COMMA, expr) { $1 }
+    | right_flexible_list(COMMA, expr) { $1 }
     ;
 params:
     | LEFT_PAREN separated_list(COMMA, expr) RIGHT_PAREN { $2 }
     ;
+
+(* http://gallium.inria.fr/blog/lr-lists/ *)
+right_flexible_list(delim, X):
+    | (* nothing *) { [] }
+    | x = X { [x] }
+    | x = X delim xs = right_flexible_list(delim, X) { x :: xs }