Fix pattern definition (#38) (#39)

Author: stevanmilic

corpus/patterns.txt

@@ -30,6 +30,7 @@ val x = y match {
   case 1 : Int => 2
   case a : B with C => d
   case _: B | _: C => 3
+  case Object.Constant => 3
 }
 
 ---
@@ -47,6 +48,9 @@ val x = y match {
         (alternative_pattern
           (typed_pattern (wildcard) (type_identifier))
           (typed_pattern (wildcard) (type_identifier)))
+        (integer_literal))
+      (case_clause
+        (stable_identifier (identifier) (identifier))
         (integer_literal))))))
 
 ============================
@@ -136,6 +140,7 @@ Capture patterns
 val x = y match {
   case a @ B(1) => a
   case b @ C(d @ (e @ X, _: Y)) => e
+  case req @ (POST | GET) -> Root / "test" => 5
 }
 
 ---
@@ -156,4 +161,11 @@ val x = y match {
                 (tuple_pattern
                   (capture_pattern (identifier) (identifier))
                   (typed_pattern (wildcard) (type_identifier))))))
-          (identifier))))))
+          (identifier))
+        (case_clause
+          (infix_pattern
+            (infix_pattern
+              (capture_pattern (identifier)
+                (tuple_pattern (alternative_pattern (identifier) (identifier))))
+              (operator_identifier) (identifier)) (operator_identifier) (string))
+              (integer_literal))))))

grammar.js

@@ -474,6 +474,7 @@ module.exports = grammar({
 
     _pattern: $ => choice(
       $.identifier,
+      $.stable_identifier,
       $.capture_pattern,
       $.tuple_pattern,
       $.case_class_pattern,
@@ -497,20 +498,20 @@ module.exports = grammar({
       field('right', $._pattern),
     )),
 
-    capture_pattern: $ => prec(PREC.assign, seq(
+    capture_pattern: $ => prec(PREC.field, seq(
       field('name', $.identifier),
       '@',
       field('pattern', $._pattern)
     )),
 
-    typed_pattern: $ => prec(-1, seq(
+    typed_pattern: $ => prec.right(seq(
       field('pattern', $._pattern),
       ':',
       field('type', $._type)
     )),
 
     // TODO: Flatten this.
-    alternative_pattern: $ => prec.left(-2, seq(
+    alternative_pattern: $ => prec.left(-1, seq(
       $._pattern,
       '|',
       $._pattern

src/grammar.json

@@ -2495,6 +2495,10 @@
           "type": "SYMBOL",
           "name": "identifier"
         },
+        {
+          "type": "SYMBOL",
+          "name": "stable_identifier"
+        },
         {
           "type": "SYMBOL",
           "name": "capture_pattern"
@@ -2640,7 +2644,7 @@
     },
     "capture_pattern": {
       "type": "PREC",
-      "value": 2,
+      "value": 6,
       "content": {
         "type": "SEQ",
         "members": [
@@ -2668,8 +2672,8 @@
       }
     },
     "typed_pattern": {
-      "type": "PREC",
-      "value": -1,
+      "type": "PREC_RIGHT",
+      "value": 0,
       "content": {
         "type": "SEQ",
         "members": [
@@ -2698,7 +2702,7 @@
     },
     "alternative_pattern": {
       "type": "PREC_LEFT",
-      "value": -2,
+      "value": -1,
       "content": {
         "type": "SEQ",
         "members": [

src/node-types.json

@@ -101,6 +101,10 @@
         "type": "null_literal",
         "named": true
       },
+      {
+        "type": "stable_identifier",
+        "named": true
+      },
       {
         "type": "string",
         "named": true