add or patterns

Author: tek

grammar/pat.js

@@ -1,4 +1,4 @@
-const {parens} = require('./util.js')
+const {parens, braces, layouted} = require('./util.js')
 
 module.exports = {
   pat_field: $ => choice(
@@ -70,13 +70,20 @@ module.exports = {
     $.pat_apply,
   ),
 
+  pat_or: $ => sep2('or', $._lpat),
+
   pat_infix: $ => seq($._lpat, $._qconop, $._pat),
 
+  _pat_infix: $ => choice(
+    $.pat_or,
+    $.pat_infix,
+  ),
+
   /**
    * Without the precs, a conflict is needed.
    */
   _pat: $ => choice(
-    prec(2, $.pat_infix),
+    prec(2, $._pat_infix),
     prec(1, $._lpat),
   ),
 

src/grammar.json

@@ -5637,6 +5637,31 @@
         }
       ]
     },
+    "pat_or": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_lpat"
+        },
+        {
+          "type": "REPEAT1",
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "or"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "_lpat"
+              }
+            ]
+          }
+        }
+      ]
+    },
     "pat_infix": {
       "type": "SEQ",
       "members": [
@@ -5654,6 +5679,19 @@
         }
       ]
     },
+    "_pat_infix": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "pat_or"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "pat_infix"
+        }
+      ]
+    },
     "_pat": {
       "type": "CHOICE",
       "members": [
@@ -5662,7 +5700,7 @@
           "value": 2,
           "content": {
             "type": "SYMBOL",
-            "name": "pat_infix"
+            "name": "_pat_infix"
           }
         },
         {