Improve function call syntax

tree-sitter-dust/corpus/built_in_function.txt

@@ -20,7 +20,6 @@ Nested Function Call
 ================================================================================
 
 (assert_equal (random_integer) 4)
-assert_equal random_integer 4
 
 --------------------------------------------------------------------------------
 
@@ -34,14 +33,4 @@ assert_equal random_integer 4
               (built_in_function)))
           (expression
             (value
-              (integer)))))))
-  (statement
-    (expression
-      (function_call
-        (built_in_function
-          (expression
-            (function_call
-              (built_in_function
-                (expression
-                  (value
-                    (integer)))))))))))
+              (integer))))))))

tree-sitter-dust/corpus/for.txt

@@ -3,7 +3,7 @@ Simple For Loop
 ================================================================================
 
 for i in [1, 2, 3] {
-  output(i)
+  (output i)
 }
 
 --------------------------------------------------------------------------------
@@ -38,7 +38,7 @@ Nested For Loop
 
 for list in list_of_lists {
   for item in list {
-    output(item)
+    (output item)
   }
 }
 

tree-sitter-dust/corpus/index.txt

@@ -108,7 +108,8 @@ x:(y):0
             (expression
               (identifier))
             (expression
-              (function_call))))
+              (function_call
+                (identifier)))))
         (expression
           (value
             (integer)))))))

tree-sitter-dust/grammar.js

@@ -46,14 +46,14 @@ module.exports = grammar({
       seq('(', $._expression_kind, ')'),
     )),
 
-    _expression_kind: $ => prec(1, choice(
+    _expression_kind: $ => choice(
       $.function_call,
       $.identifier,
       $.index,
       $.logic,
       $.math,
       $.value,
-    )),
+    ),
 
     _expression_list: $ => repeat1(prec.right(seq(
       $.expression,
@@ -292,14 +292,16 @@ module.exports = grammar({
       field('body', $.block),
     ),
 
-    function_call: $ => prec.right(choice(
+    function_call: $ => prec.right(seq(
       '(',
-      $.built_in_function,
-      $._context_defined_function,
+      choice(
+        $.built_in_function,
+        $._context_defined_function,
+      ),
       ')',
     )),
 
-    _context_defined_function: $ => prec.right(seq(
+    _context_defined_function: $ => prec.right(1, seq(
       $.identifier,
       optional($._expression_list),
     )),

tree-sitter-dust/src/grammar.json

@@ -162,37 +162,33 @@
       }
     },
     "_expression_kind": {
-      "type": "PREC",
-      "value": 1,
-      "content": {
-        "type": "CHOICE",
-        "members": [
-          {
-            "type": "SYMBOL",
-            "name": "function_call"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "identifier"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "index"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "logic"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "math"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "value"
-          }
-        ]
-      }
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "function_call"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "identifier"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "index"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "logic"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "math"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "value"
+        }
+      ]
     },
     "_expression_list": {
       "type": "REPEAT1",
@@ -1236,19 +1232,24 @@
       "type": "PREC_RIGHT",
       "value": 0,
       "content": {
-        "type": "CHOICE",
+        "type": "SEQ",
         "members": [
           {
             "type": "STRING",
             "value": "("
           },
           {
-            "type": "SYMBOL",
-            "name": "built_in_function"
-          },
-          {
-            "type": "SYMBOL",
-            "name": "_context_defined_function"
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "SYMBOL",
+                "name": "built_in_function"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "_context_defined_function"
+              }
+            ]
           },
           {
             "type": "STRING",
@@ -1259,7 +1260,7 @@
     },
     "_context_defined_function": {
       "type": "PREC_RIGHT",
-      "value": 0,
+      "value": 1,
       "content": {
         "type": "SEQ",
         "members": [

tree-sitter-dust/src/node-types.json

@@ -255,7 +255,7 @@
     "fields": {},
     "children": {
       "multiple": true,
-      "required": false,
+      "required": true,
       "types": [
         {
           "type": "built_in_function",