fix: DOT operator in string concatenation is optional

clients/vscode-hlasmplugin/CHANGELOG.md

@@ -24,6 +24,7 @@
 - Attribute expressions ending with dot are not parsed correctly
 - Improve evaluation and diagnostics of conditional assembler expressions
 - Operands of dynamically generated statements may be incorrectly parsed
+- DOT operator in string concatenation is optional
 
 ## [0.14.0](https://github.com/eclipse/che-che4z-lsp-for-hlasm/compare/0.13.0...0.14.0) (2021-08-18)
 

parser_library/src/parsing/grammar/ca_expr_rules.g4

@@ -328,7 +328,7 @@ ca_string returns [ca_expr_ptr ca_expr]
 	{
 		$ca_expr = std::move($ca_string_b.ca_expr);
 	}
-	| tmp=ca_string dot ca_string_b
+	| tmp=ca_string dot? ca_string_b
 	{
 		auto r = provider.get_range($tmp.ctx->getStart(), $ca_string_b.ctx->getStop());
 		$ca_expr = std::make_unique<ca_basic_binary_operator<ca_conc>>(std::move($tmp.ca_expr), std::move($ca_string_b.ca_expr), r);

parser_library/test/semantics/concatenation_test.cpp

@@ -14,6 +14,7 @@
 
 #include "gmock/gmock.h"
 
+#include "../common_testing.h"
 #include "semantics/concatenation_term.h"
 
 using namespace hlasm_plugin::parser_library::semantics;
@@ -83,4 +84,46 @@ TEST(concatenation, contains_var_sym)
 
         EXPECT_EQ(var, nullptr);
     }
-}
+}
+
+TEST(concatenation, no_dots)
+{
+    std::string input = R"(
+&A SETC ' '
+&A SETC '&A'(1,1)'&A'(1,1)
+)";
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(a.diags().empty());
+    EXPECT_EQ(get_var_value<C_t>(a.hlasm_ctx(), "A"), "  ");
+}
+
+TEST(concatenation, with_dots)
+{
+    std::string input = R"(
+&A SETC ' '
+&A SETC '&A'(1,1).'&A'(1,1)
+)";
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(a.diags().empty());
+    EXPECT_EQ(get_var_value<C_t>(a.hlasm_ctx(), "A"), "  ");
+}
+
+TEST(concatenation, no_dots_without_subscript)
+{
+    std::string input = R"(
+&A SETC ' '
+&A SETC '&A''&A'
+)";
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(a.diags().empty());
+    EXPECT_EQ(get_var_value<C_t>(a.hlasm_ctx(), "A"), " ' ");
+}