Disambiguate parenthesized range expressions from call expressions (#100)

* disambiguate parenthesized range expressions from call expressions

* regenerate parser for 'range_expression'

Co-authored-by: resolritter <[email protected]>

Author: resolritter

corpus/expressions.txt

@@ -125,6 +125,9 @@ Range expressions
 ..;
 1..b;
 a..b;
+1..(1);
+(1)..1;
+(1)..(1);
 
 ---
 
@@ -134,7 +137,16 @@ a..b;
   (range_expression (integer_literal))
   (range_expression)
   (range_expression (integer_literal) (identifier))
-  (range_expression (identifier) (identifier)))
+  (range_expression (identifier) (identifier))
+  (range_expression
+    (integer_literal)
+    (parenthesized_expression (integer_literal)))
+  (range_expression
+    (parenthesized_expression (integer_literal))
+    (integer_literal))
+  (range_expression
+    (parenthesized_expression (integer_literal))
+    (parenthesized_expression (integer_literal))))
 
 ============================================
 Assignment expressions
@@ -802,4 +814,4 @@ let three_ranges = [const { (0..=5).into_inner() }; 3];
                   (integer_literal)))
               field: (field_identifier))
             arguments: (arguments))))
-      length: (integer_literal))))
+      length: (integer_literal))))

grammar.js

@@ -1,4 +1,5 @@
 const PREC = {
+  range: 15,
   call: 14,
   field: 13,
   unary: 11,
@@ -11,7 +12,6 @@ const PREC = {
   comparative: 4,
   and: 3,
   or: 2,
-  range: 1,
   assign: 0,
   closure: -1,
 }
@@ -914,7 +914,10 @@ module.exports = grammar({
     ),
 
     range_expression: $ => prec.left(PREC.range, choice(
-      seq($._expression, choice('..', '...', '..='), $._expression),
+      prec.left(
+        PREC.range + 1,
+        seq($._expression, choice('..', '...', '..='), $._expression)
+      ),
       seq($._expression, '..'),
       seq('..', $._expression),
       '..'

src/grammar.json

@@ -5025,39 +5025,43 @@
     },
     "range_expression": {
       "type": "PREC_LEFT",
-      "value": 1,
+      "value": 15,
       "content": {
         "type": "CHOICE",
         "members": [
           {
-            "type": "SEQ",
-            "members": [
-              {
-                "type": "SYMBOL",
-                "name": "_expression"
-              },
-              {
-                "type": "CHOICE",
-                "members": [
-                  {
-                    "type": "STRING",
-                    "value": ".."
-                  },
-                  {
-                    "type": "STRING",
-                    "value": "..."
-                  },
-                  {
-                    "type": "STRING",
-                    "value": "..="
-                  }
-                ]
-              },
-              {
-                "type": "SYMBOL",
-                "name": "_expression"
-              }
-            ]
+            "type": "PREC_LEFT",
+            "value": 16,
+            "content": {
+              "type": "SEQ",
+              "members": [
+                {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                },
+                {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "STRING",
+                      "value": ".."
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "..."
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "..="
+                    }
+                  ]
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              ]
+            }
           },
           {
             "type": "SEQ",