Added value expression parsing flag EXPR_PARSE_SINGLE, which means to read

only a single expression and then quit immediately.  Useful for parsing
expressions that begin with a left parenthesis and are known to end at the
right parenthesis.

3 files changed, 11 insertions, 9 deletions

diff --git a/src/format.cc b/src/format.cc
index 3b3c562a..121cdf63 100644
--- a/src/format.cc
+++ b/src/format.cc
@@ -212,7 +212,7 @@ format_t::element_t * format_t::parse_elements(const string& fmt)
     case '[': {
       std::istringstream str(p);
       current->type = element_t::EXPR;
-      current->expr.parse(str, EXPR_PARSE_PARTIAL);
+      current->expr.parse(str, EXPR_PARSE_SINGLE);
       istream_pos_type pos = str.tellg();
       current->expr.set_text(string(p, p + long(pos)));
       p += long(pos) - 1;
diff --git a/src/parser.cc b/src/parser.cc
index 922e3453..eabcb845 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -64,7 +64,7 @@ expr_t::parser_t::parse_value_term(std::istream& in,
 
       ptr_op_t call_node(new op_t(op_t::O_CALL));
       call_node->set_left(node);
-      call_node->set_right(parse_value_expr(in, tflags | EXPR_PARSE_PARTIAL));
+      call_node->set_right(parse_value_expr(in, tflags | EXPR_PARSE_SINGLE));
 
       tok = next_token(in, tflags);
       if (tok.kind != token_t::RPAREN)
@@ -85,7 +85,7 @@ expr_t::parser_t::parse_value_term(std::istream& in,
   }
 
   case token_t::LPAREN:
-    node = parse_value_expr(in, tflags | EXPR_PARSE_PARTIAL);
+    node = parse_value_expr(in, tflags | EXPR_PARSE_SINGLE);
     if (! node)
       throw_(parse_error, tok.symbol << " operator not followed by expression");
 
@@ -355,7 +355,7 @@ expr_t::parser_t::parse_value_expr(std::istream& in,
 {
   ptr_op_t node(parse_querycolon_expr(in, tflags));
 
-  if (node) {
+  if (node && ! (tflags & EXPR_PARSE_SINGLE)) {
     token_t& tok = next_token(in, tflags);
 
     if (tok.kind == token_t::COMMA) {
@@ -376,7 +376,8 @@ expr_t::parser_t::parse_value_expr(std::istream& in,
 	tok.unexpected();
     }
   }
-  else if (! (tflags & EXPR_PARSE_PARTIAL)) {
+  else if (! (tflags & (EXPR_PARSE_PARTIAL |
+			EXPR_PARSE_SINGLE))) {
     throw_(parse_error, "Failed to parse value expression");
   }
 
diff --git a/src/parser.h b/src/parser.h
index 294d28ff..a9828c05 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -41,10 +41,11 @@ class expr_t::parser_t : public noncopyable
 {
 #define EXPR_PARSE_NORMAL     0x00
 #define EXPR_PARSE_PARTIAL    0x01
-#define EXPR_PARSE_NO_MIGRATE 0x02
-#define EXPR_PARSE_NO_REDUCE  0x04
-#define EXPR_PARSE_NO_ASSIGN  0x08
-#define EXPR_PARSE_NO_DATES   0x10
+#define EXPR_PARSE_SINGLE     0x02
+#define EXPR_PARSE_NO_MIGRATE 0x04
+#define EXPR_PARSE_NO_REDUCE  0x08
+#define EXPR_PARSE_NO_ASSIGN  0x10
+#define EXPR_PARSE_NO_DATES   0x20
 
 public:
   typedef uint_least8_t flags_t;