Add array concat operator

editors/tree-sitter-decodal/corpus/basic.txt

@@ -129,3 +129,32 @@ Logical and comparison
         left: (unary_expression
           operand: (identifier))
         right: (literal (boolean))))))
+
+==================
+Array concat
+==================
+{
+  roles = ["read"] ++ ["write", "admin"];
+  ports = [8000 + 80] ++ [9443];
+}
+---
+
+(source_file
+  (object
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (array
+          (literal (string)))
+        right: (array
+          (literal (string))
+          (literal (string)))))
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (array
+          (binary_expression
+            left: (literal (integer))
+            right: (literal (integer))))
+        right: (array
+          (literal (integer)))))))

editors/tree-sitter-decodal/grammar.js

@@ -5,11 +5,12 @@ const PREC = {
   OR: 4,
   LOGICAL_AND: 5,
   COMPARE: 6,
-  ADD: 7,
-  MUL: 8,
-  UNARY: 9,
-  CALL: 10,
-  PATH: 11,
+  CONCAT: 7,
+  ADD: 8,
+  MUL: 9,
+  UNARY: 10,
+  CALL: 11,
+  PATH: 12,
 };
 
 function commaSep(rule) {
@@ -192,6 +193,11 @@ module.exports = grammar({
         field('operator', choice('==', '!=', '>', '>=', '<', '<=')),
         field('right', $._expression),
       )),
+      prec.left(PREC.CONCAT, seq(
+        field('left', $._expression),
+        field('operator', token(prec(2, '++'))),
+        field('right', $._expression),
+      )),
       prec.left(PREC.ADD, seq(
         field('left', $._expression),
         field('operator', choice('+', '-')),

editors/tree-sitter-decodal/queries/highlights.scm

@@ -21,6 +21,7 @@
   "-"
   "*"
   "/"
+  "++"
   "&&"
   "||"
   "!"

editors/tree-sitter-decodal/src/grammar.json

@@ -716,7 +716,7 @@
     },
     "call_expression": {
       "type": "PREC_LEFT",
-      "value": 10,
+      "value": 11,
       "content": {
         "type": "SEQ",
         "members": [
@@ -786,7 +786,7 @@
     },
     "path_expression": {
       "type": "PREC_LEFT",
-      "value": 11,
+      "value": 12,
       "content": {
         "type": "SEQ",
         "members": [
@@ -815,7 +815,7 @@
     },
     "comparison_constraint": {
       "type": "PREC_RIGHT",
-      "value": 10,
+      "value": 11,
       "content": {
         "type": "SEQ",
         "members": [
@@ -857,7 +857,7 @@
     },
     "unary_expression": {
       "type": "PREC",
-      "value": 9,
+      "value": 10,
       "content": {
         "type": "SEQ",
         "members": [
@@ -1033,6 +1033,46 @@
         {
           "type": "PREC_LEFT",
           "value": 7,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "TOKEN",
+                  "content": {
+                    "type": "PREC",
+                    "value": 2,
+                    "content": {
+                      "type": "STRING",
+                      "value": "++"
+                    }
+                  }
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 8,
           "content": {
             "type": "SEQ",
             "members": [
@@ -1074,7 +1114,7 @@
         },
         {
           "type": "PREC_LEFT",
-          "value": 8,
+          "value": 9,
           "content": {
             "type": "SEQ",
             "members": [

editors/tree-sitter-decodal/src/node-types.json

@@ -172,6 +172,10 @@
             "type": "+",
             "named": false
           },
+          {
+            "type": "++",
+            "named": false
+          },
           {
             "type": "-",
             "named": false
@@ -1692,6 +1696,10 @@
     "type": "+",
     "named": false
   },
+  {
+    "type": "++",
+    "named": false
+  },
   {
     "type": ",",
     "named": false