From c194a34efb8fd72b0177792b2c7c7eef45590bf1 Mon Sep 17 00:00:00 2001
From: Konstantin Nazarov <mail@knazarov.com>
Date: Wed, 4 Sep 2024 23:24:12 +0100
Subject: [PATCH] Add self-evaluating symbols that start with ":"

---
 src/compiler.cpp     | 17 +++++++++++++++++
 test/collections.vli |  4 ++++
 2 files changed, 21 insertions(+)

diff --git a/src/compiler.cpp b/src/compiler.cpp
index 57b0ac1..836e69b 100644
--- a/src/compiler.cpp
+++ b/src/compiler.cpp
@@ -897,6 +897,23 @@ Result<Expression> Compiler::compile_symbol(Context& context,
                                             const Value& value) {
   Expression ex = TRY(Expression::create());
 
+  // Symbol may be self-evaluating (e.g. :foo), in which case we just use it as
+  // its own value
+
+  if (value.is<Symbol>()) {
+    Symbol& sym = *value.to<Symbol>();
+
+    if (sym.size() > 0 && TRY(sym[0]) == ':') {
+      int64_t c = TRY(context.add_const(value));
+
+      uint64_t reg = context.alloc_reg();
+      TRY(ex.add_opcode(Oc::Mov, {0, (int64_t)reg}, {1, (int64_t)c}));
+
+      ex.reg = reg;
+      return std::move(ex);
+    }
+  }
+
   auto maybe_reg = context.get_var(TRY(value.copy()));
 
   if (!maybe_reg.has_error()) {
diff --git a/test/collections.vli b/test/collections.vli
index c4c290b..0f85575 100644
--- a/test/collections.vli
+++ b/test/collections.vli
@@ -9,3 +9,7 @@
 
 (assert (= (get {1 2 3 4} 3)
            4))
+
+;; Accessing collections by symbol
+(assert (= (get {:foo 1 :bar 2} :bar)
+           2))