More.

grammar.js

@@ -21,50 +21,65 @@ module.exports = grammar({
         $.bool,
         $.word,
         $.binexp,
-        $.callexp,
-        $.parexp,
-        $.block,
+        $.eqexp,
         $.vardef,
-        $.lambda,
+        $.callexp,
         $.funcdef,
+        $.lambda,
+        $.seqexp,
         $.ifexp,
+        $.tern_ifexp,
+        $.block,
+        $.parexp,
       ),
 
     num: (_) => /\d+/,
-    bool: (_) => choice("TRUE", "T", "FALSE", "F"),
+
+    bool: (_) => choice("T", "F"),
+
     word: (_) => /[a-zA-Z_]\w*/,
 
-    binexp: ($) =>
+    seqexp: ($) =>
       prec.left(
-        1,
-        seq(
-          field("left", $._exp),
-          field("op", choice("+", "-", "*", "/", "eq")),
-          field("right", $._exp),
+        -1, // lowest
+        seq(field("first", $._exp), repeat1(seq(";", field("rest", $._exp)))),
+      ),
+
+    vardef: ($) =>
+      prec.right(1, seq(field("name", $.word), "=", field("value", $._exp))),
+
+    eqexp: ($) =>
+      prec.left(2, seq(field("left", $._exp), "==", field("right", $._exp))),
+
+    binexp: ($) =>
+      choice(
+        prec.left(
+          3,
+          seq(
+            field("left", $._exp),
+            field("op", choice("+", "-")),
+            field("right", $._exp),
+          ),
+        ),
+        prec.left(
+          4,
+          seq(
+            field("left", $._exp),
+            field("op", choice("*", "/")),
+            field("right", $._exp),
+          ),
         ),
       ),
 
     callexp: ($) =>
       prec.left(
-        1, // lower than funcdef
+        5,
         seq(field("fn", $.word), "(", optional(commaSep($._exp)), ")"),
       ),
 
-    parexp: ($) => seq("(", $._exp, ")"),
-    block: ($) => seq("{", repeat($._exp), "}"),
-
-    vardef: ($) =>
-      prec.right(1, seq(field("name", $.word), "=", field("value", $._exp))),
-
-    lambda: ($) =>
-      prec.right(
-        2,
-        seq("\\", field("params", $.params), field("body", $._exp)),
-      ),
-
     funcdef: ($) =>
       prec.right(
-        3, // higher precedence than call
+        6,
         seq(
           field("name", $.word),
           field("params", $.params),
@@ -72,33 +87,36 @@ module.exports = grammar({
         ),
       ),
 
+    lambda: ($) =>
+      prec.right(
+        6,
+        seq("\\", field("params", $.params), field("body", $._exp)),
+      ),
+
+    parexp: ($) => seq("(", $._exp, ")"),
+
+    block: ($) => seq("{", repeat($._exp), "}"),
+
     params: ($) => seq("(", optional(commaSep($.word)), ")"),
 
     ifexp: ($) =>
-      choice(
-        seq(
-          "_if",
-          "(",
-          field("cond", $._exp),
-          ",",
-          field("then", $._exp),
-          ",",
-          field("else", $._exp),
-          ")",
-        ),
+      prec.right(
         seq(
           "if",
           field("cond", $._exp),
           field("then", $._exp),
-          choice(seq("else", field("else", $._exp)), field("else", $._exp)),
-        ),
-        seq(
-          "?",
-          field("cond", $._exp),
-          field("then", $._exp),
+          optional("else"),
           field("else", $._exp),
         ),
       ),
+
+    tern_ifexp: ($) =>
+      seq(
+        "?",
+        field("cond", $._exp),
+        field("then", $._exp),
+        field("else", $._exp),
+      ),
   },
 });