implemented break for while-loop case

ast.ml - added break and cont statements
item.ml - added break and cont statements
lexer.mll - added break and cont statements
token.ml - added break and cont statements
trans.ml - implemented the break statement for the while-loop case
         - replaced hash table accesses with get_stmt_depth where needed
type.ml = added break and cont statements
typestate.ml - implemented the break statement for the while-loop case
             - added shorthand filter_live_block_slots
walk.ml - added break and cont statements
while-with-break.rs - code for testing while loops

4 files changed, 20 insertions, 1 deletions

diff --git a/src/boot/fe/ast.ml b/src/boot/fe/ast.ml
index 54c48f7d090..46a87dfe01b 100644
--- a/src/boot/fe/ast.ml
+++ b/src/boot/fe/ast.ml
@@ -207,6 +207,8 @@ and stmt' =
   | STMT_put_each of (lval * (atom array))
   | STMT_ret of (atom option)
   | STMT_be of (lval * (atom array))
+  | STMT_break
+  | STMT_cont
   | STMT_alt_tag of stmt_alt_tag
   | STMT_alt_type of stmt_alt_type
   | STMT_alt_port of stmt_alt_port
@@ -1228,6 +1230,10 @@ and fmt_stmt_body (ff:Format.formatter) (s:stmt) : unit =
           fmt_atoms ff az;
           fmt ff ";";
 
+      | STMT_break -> fmt ff "break;";
+
+      | STMT_cont -> fmt ff "cont;";
+
       | STMT_block b -> fmt_block ff b.node
 
       | STMT_copy (lv, ex) ->
diff --git a/src/boot/fe/item.ml b/src/boot/fe/item.ml
index 3d3bf84fc17..c1746cc2f99 100644
--- a/src/boot/fe/item.ml
+++ b/src/boot/fe/item.ml
@@ -188,7 +188,14 @@ and parse_stmts_including_none (ps:pstate) : Ast.stmt array =
           let (stmts, atom) = ctxt "stmts: log value" parse_expr_atom ps in
             expect ps SEMI;
             spans ps stmts apos (Ast.STMT_log atom)
-
+      | BREAK ->
+          bump ps;
+          expect ps SEMI;
+          [| span ps apos (lexpos ps) Ast.STMT_break |]
+      | CONT ->
+          bump ps;
+          expect ps SEMI;
+          [| span ps apos (lexpos ps) Ast.STMT_cont |]
       | CHECK ->
           bump ps;
           begin
diff --git a/src/boot/fe/lexer.mll b/src/boot/fe/lexer.mll
index 763b50c91d9..151af827657 100644
--- a/src/boot/fe/lexer.mll
+++ b/src/boot/fe/lexer.mll
@@ -113,6 +113,8 @@
                 ("const", CONST);
 
                 ("log", LOG);
+                ("break", BREAK);
+                ("cont", CONT);
                 ("spawn", SPAWN);
                 ("thread", THREAD);
                 ("yield", YIELD);
diff --git a/src/boot/fe/token.ml b/src/boot/fe/token.ml
index 85dd2a13f2d..cd41ec2fec5 100644
--- a/src/boot/fe/token.ml
+++ b/src/boot/fe/token.ml
@@ -71,6 +71,8 @@ type token =
   | PUT
   | RET
   | BE
+  | BREAK
+  | CONT
 
   (* Type and type-state keywords *)
   | TYPE
@@ -226,6 +228,8 @@ let rec string_of_tok t =
     | PUT        -> "put"
     | RET        -> "ret"
     | BE         -> "be"
+    | BREAK      -> "break"
+    | CONT       -> "cont"
 
     (* Type and type-state keywords *)
     | TYPE       -> "type"