irc/parser: fix list parsing and function application

Fixes bug where `concat [1 2 3] [4 5 6]` tried to apply integer 1
as a function.

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I6f373dd83bcac9e59286b0448472200b6a6a6964

src/irc/parser.cpp

@@ -636,8 +636,9 @@ private:
 
   void tokenize_ident() {
     size_t start = pos;
-    while (pos < input.size() && (isalnum(input[pos]) || input[pos] == '_' || input[pos] == '-' ||
+    // Note: Don't include '.' here - it's used for selection (a.b.c)
-                                  input[pos] == '+' || input[pos] == '.'))
+    // URIs are handled separately by checking for '://' pattern
+    while (pos < input.size() && (isalnum(input[pos]) || input[pos] == '_' || input[pos] == '-'))
       pos++;
     std::string ident = input.substr(start, pos - start);
 
@@ -927,16 +928,25 @@ public:
     std::shared_ptr<Node> left = parse_expr3();
 
     while (true) {
-      if (current().type == Token::LBRACKET) {
+      if (current().type == Token::STRING) {
-        advance();
-        auto arg = parse_expr();
-        expect(Token::RBRACKET);
-        left = std::make_shared<Node>(AppNode(left, arg));
-      } else if (current().type == Token::STRING) {
         Token s = current();
         advance();
         auto arg = std::make_shared<Node>(ConstStringNode(s.value));
         left = std::make_shared<Node>(AppNode(left, arg));
+      } else if (current().type == Token::LPAREN) {
+        // Function application with parenthesized argument: func (expr)
+        advance();
+        auto arg = parse_expr();
+        expect(Token::RPAREN);
+        left = std::make_shared<Node>(AppNode(left, arg));
+      } else if (current().type == Token::IDENT || current().type == Token::INT ||
+                 current().type == Token::FLOAT || current().type == Token::BOOL ||
+                 current().type == Token::PATH || current().type == Token::LOOKUP_PATH ||
+                 current().type == Token::URI || current().type == Token::LBRACKET) {
+        // Juxtaposition application: f x
+        // Parse the argument as a primary expression (which handles lists, etc.)
+        auto arg = parse_expr3();
+        left = std::make_shared<Node>(AppNode(left, arg));
       } else {
         break;
       }
@@ -969,6 +979,16 @@ public:
       return expr;
     }
 
+    // Handle rec { ... } syntax
+    if (consume(Token::REC)) {
+      expect(Token::LBRACE);
+      auto attrs = parse_attrs();
+      if (auto* attrset = attrs->get_if<AttrsetNode>()) {
+        attrset->recursive = true;
+      }
+      return attrs;
+    }
+
     if (consume(Token::LBRACE)) {
       return parse_attrs();
     }
@@ -1151,6 +1171,35 @@ public:
     return std::make_shared<Node>(std::move(attrs));
   }
 
+  // Parse a list element: supports selections but NOT juxtaposition application
+  // This prevents [1 2 3] from being parsed as ((1 2) 3)
+  std::shared_ptr<Node> parse_list_element() {
+    auto left = parse_expr3();
+
+    // Handle selections (a.b.c)
+    while (current().type == Token::DOT) {
+      advance();
+      Token name = current();
+      if (name.type == Token::IDENT) {
+        advance();
+        auto attr = std::make_shared<Node>(ConstStringNode(name.value));
+        left = std::make_shared<Node>(SelectNode(left, attr));
+        continue;
+      }
+      break;
+    }
+
+    // Check for 'or' default value
+    if (left->get_if<SelectNode>() && current().type == Token::IDENT && current().value == "or") {
+      advance();
+      auto default_expr = parse_expr3();
+      auto* select = left->get_if<SelectNode>();
+      select->default_expr = default_expr;
+    }
+
+    return left;
+  }
+
   std::shared_ptr<Node> parse_list() {
     std::vector<std::shared_ptr<Node>> elements;
 
@@ -1158,18 +1207,14 @@ public:
       return std::make_shared<Node>(ListNode(elements));
     }
 
-    while (current().type != Token::RBRACKET) {
+    while (current().type != Token::RBRACKET && current().type != Token::EOF_) {
-      elements.push_back(parse_expr());
+      elements.push_back(parse_list_element());
-      if (!consume(Token::RBRACKET)) {
+      if (current().type == Token::RBRACKET) {
-        // Elements are whitespace-separated in Nix, no comma required
+        break;
-        // But we'll continue parsing until we hit ]
-      } else {
-        // Found closing bracket
-        return std::make_shared<Node>(ListNode(elements));
       }
     }
 
-    // Unreachable, but for safety
+    expect(Token::RBRACKET);
     return std::make_shared<Node>(ListNode(elements));
   }