Add select subexpressions

examples/select.sql

@@ -2,4 +2,8 @@
 SELECT foo, bar, t.col1 AS baz
 FROM table1, table2 AS t
 WHERE foo > t.col1
-GROUP BY lower(foo)
+GROUP BY lower(foo);
+
+-- Example nested select query
+SELECT t.a, (SELECT 1) AS baz, (SELECT 2)
+FROM table1, (SELECT a FROM foo WHERE b > 100) AS t;

grammar.js

@@ -194,6 +194,7 @@ module.exports = grammar({
       prec.left(seq(caseInsensitive("SELECT"), optional($.select_clause_body))),
     from_clause: $ =>
       seq(caseInsensitive("FROM"), commaSep1($._aliasable_expression)),
+    select_subexpression: $ => seq("(", $.select_statement, ")"),
     in_expression: $ =>
       prec.left(
         1,
@@ -341,6 +342,7 @@ module.exports = grammar({
         $.type_cast,
         $.binary_expression,
         $.argument_reference,
+        $.select_subexpression,
       ),
   },
 });

src/grammar.json

@@ -1369,6 +1369,23 @@
         }
       ]
     },
+    "select_subexpression": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "("
+        },
+        {
+          "type": "SYMBOL",
+          "name": "select_statement"
+        },
+        {
+          "type": "STRING",
+          "value": ")"
+        }
+      ]
+    },
     "in_expression": {
       "type": "PREC_LEFT",
       "value": 1,
@@ -2399,6 +2416,10 @@
         {
           "type": "SYMBOL",
           "name": "argument_reference"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "select_subexpression"
         }
       ]
     }

src/node-types.json

@@ -74,6 +74,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -169,6 +173,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -240,6 +248,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -311,6 +323,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -382,6 +398,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -453,6 +473,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -555,6 +579,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -954,6 +982,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1025,6 +1057,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1138,6 +1174,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1236,6 +1276,10 @@
             "type": "number",
             "named": true
           },
+          {
+            "type": "select_subexpression",
+            "named": true
+          },
           {
             "type": "string",
             "named": true
@@ -1333,6 +1377,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1404,6 +1452,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1483,6 +1535,10 @@
           "type": "ordered_expression",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1558,6 +1614,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1732,6 +1792,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1818,6 +1882,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -1989,6 +2057,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -2031,6 +2103,21 @@
       ]
     }
   },
+  {
+    "type": "select_subexpression",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "select_statement",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "setof",
     "named": true,
@@ -2166,6 +2253,10 @@
             "type": "number",
             "named": true
           },
+          {
+            "type": "select_subexpression",
+            "named": true
+          },
           {
             "type": "string",
             "named": true
@@ -2242,6 +2333,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true
@@ -2353,6 +2448,10 @@
           "type": "number",
           "named": true
         },
+        {
+          "type": "select_subexpression",
+          "named": true
+        },
         {
           "type": "string",
           "named": true

test/corpus/statements.txt

@@ -35,6 +35,21 @@ SELECT a, b FROM table1;
         (select_clause (select_clause_body (identifier) (identifier)))
         (from_clause (identifier)))) 
 
+================
+SELECT statement with SELECT subexpression
+================
+
+SELECT (SELECT 1) AS a
+
+---
+
+(source_file
+    (select_statement
+        (select_clause (select_clause_body (alias 
+                (select_subexpression 
+                    (select_statement (select_clause (select_clause_body (number)))))
+                (identifier))))))
+
 ================
 SELECT statement with aliases
 ================

test/highlight/select.sql

@@ -27,6 +27,16 @@ where a = b
 group by a, b
 -- <- keyword
 --    ^ keyword
-order by lower(a), b
+order by lower(a), b;
 -- <- keyword
 --    ^ keyword
+
+SELECT (SELECT 1), a
+-- <- keyword
+--         ^ keyword
+--             ^ number
+FROM (SELECT a FROM table) AS b;
+-- <- keyword
+--     ^ keyword
+--             ^ keyword  
+--                         ^ keyword