Add yield syntax

Cargo.toml

@@ -3,7 +3,7 @@ name = "dust-lang"
 description = "Data-Oriented Programming Language"
 version = "0.3.5"
 repository = "https://github.com/tree-sitter/tree-sitter-dust"
-edition = "2018"
+edition = "2021"
 license = "MIT"
 
 [[bin]]

tree-sitter-dust/corpus/yield.txt

@@ -0,0 +1,15 @@
+================================================================================
+Simple Yield
+================================================================================
+
+1 -> (output)
+
+--------------------------------------------------------------------------------
+
+================================================================================
+Yield Chain
+================================================================================
+
+x -> (foo) -> (bar) -> (abc)
+
+--------------------------------------------------------------------------------

tree-sitter-dust/grammar.js

@@ -42,6 +42,12 @@ module.exports = grammar({
       optional(';'),
     )),
 
+    yield: $ => prec.left(seq(
+      $.expression,
+      '->',
+      $.function_call,
+    )),
+  
     expression: $ => prec.right(choice(
       $._expression_kind,
       seq('(', $._expression_kind, ')'),
@@ -54,6 +60,7 @@ module.exports = grammar({
       $.logic,
       $.math,
       $.value,
+      $.yield,
     ),
 
     _expression_list: $ => repeat1(prec.right(seq(

tree-sitter-dust/src/grammar.json

@@ -135,6 +135,27 @@
         ]
       }
     },
+    "yield": {
+      "type": "PREC_LEFT",
+      "value": 0,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "SYMBOL",
+            "name": "expression"
+          },
+          {
+            "type": "STRING",
+            "value": "->"
+          },
+          {
+            "type": "SYMBOL",
+            "name": "function_call"
+          }
+        ]
+      }
+    },
     "expression": {
       "type": "PREC_RIGHT",
       "value": 0,
@@ -191,6 +212,10 @@
         {
           "type": "SYMBOL",
           "name": "value"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "yield"
         }
       ]
     },

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

@@ -127,6 +127,10 @@
         {
           "type": "value",
           "named": true
+        },
+        {
+          "type": "yield",
+          "named": true
         }
       ]
     }
@@ -746,6 +750,25 @@
       ]
     }
   },
+  {
+    "type": "yield",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": true,
+      "types": [
+        {
+          "type": "expression",
+          "named": true
+        },
+        {
+          "type": "function_call",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "!=",
     "named": false
@@ -790,6 +813,10 @@
     "type": "-=",
     "named": false
   },
+  {
+    "type": "->",
+    "named": false
+  },
   {
     "type": "..",
     "named": false