X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;ds=sidebyside;f=src%2Fparser.mly;h=7146a999a47ee21ee00874b45f4572201902cdc2;hb=881b2e9b7bad0da8f44418e9e6558710db5ce690;hp=c6f961d2e42285e3add102ed9bc12b0d0c060840;hpb=6afdc65fcdb592dccb751849f65b1f482ef97cd6;p=goals.git

diff --git a/src/parser.mly b/src/parser.mly
index c6f961d..7146a99 100644
--- a/src/parser.mly
+++ b/src/parser.mly
@@ -21,28 +21,67 @@
 open Utils
 open Printf
 
-(* This is initialized with Lexer.read once the program
- * starts.  Doing this avoids a circular dependency caused
- * by include files.
+(* 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
 
@@ -57,32 +96,12 @@ file:
 
 stmts:
     | (* none *) { Ast.Env.empty }
-    | stmts INCLUDE STRING
-    {
-      let env = $1 in
-      let filename = Ast.substitute env $loc $3 in
-      let rec find_on_include_path =
-        function
-        | [] -> filename
-        | inc :: incs ->
-           let path = inc // filename in
-           if Sys.file_exists path then path
-           else find_on_include_path incs
-      in
-      let filename =
-        if Filename.is_implicit filename then
-          find_on_include_path Cmdline.includes
-        else filename in
-      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 reader =
-        match !lexer_read with None -> assert false | Some r -> r in
-      let env' = file reader lexbuf in
-      close_in fp;
-      Ast.Env.merge env env'
-    }
-    | stmts stmt  { let name, expr = $2 in Ast.Env.add name expr $1 }
+    | 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:
@@ -92,16 +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
     {
-      $2, Ast.ETactic ($loc, ($3, $5))
+      $2, Ast.ETacticDefn ($loc, ($3, $5))
     }
     | LET ID EQUALS expr { $2, $4 }
     ;
@@ -115,13 +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, $2) }
+    | TACTIC pattern_params { Ast.PTactic ($loc, $1, $2) }
     ;
 pattern_params:
     | LEFT_PAREN separated_list(COMMA, pattern_param) RIGHT_PAREN { $2 }
@@ -131,15 +159,21 @@ pattern_param:
     ;
 
 expr:
-    | ID params  { Ast.ECallGoal ($loc, $1, $2) }
+    | ID params  { Ast.ECall ($loc, $1, $2) }
     | ID         { Ast.EVar ($loc, $1) }
-    | TACTIC params { Ast.ECallTactic ($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 }