Refactor SQL syntax from # to @ for data source references

.copilot/README.md

@@ -234,7 +234,7 @@ public class MyLibrary : LibraryBase
 
 ### 1. Lexical Analysis
 ```
-"SELECT Name FROM #mydata.source('param')" → Tokens
+"SELECT Name FROM @mydata.source('param')" → Tokens
 ```
 
 ### 2. Parsing
@@ -338,7 +338,7 @@ dotnet test --filter "TestCategory=Integration"
 // Using test infrastructure pattern
 var schemaProvider = new BasicSchemaProvider<MyEntity>(dataSources);
 var compiledQuery = InstanceCreator.CompileForExecution(
-    "SELECT Name, Value FROM #schema.table('param')",
+    "SELECT Name, Value FROM @schema.table('param')",
     Guid.NewGuid().ToString(),
     schemaProvider,
     loggerResolver);
@@ -351,8 +351,8 @@ var results = compiledQuery.Run();
 ```csharp
 var query = @"
     SELECT a.Name, b.Value 
-    FROM #source1.data() a 
-    INNER JOIN #source2.data() b ON a.Id = b.Id
+    FROM @source1.data() a 
+    INNER JOIN @source2.data() b ON a.Id = b.Id
     WHERE a.CreatedAt > '2023-01-01'
     ORDER BY a.Name";
 
@@ -382,7 +382,7 @@ public class MyFeatureTests : BasicEntityTestBase
     public void Should_Parse_Complex_Query()
     {
         // Arrange
-        var query = "SELECT Name FROM #test.data()";
+        var query = "SELECT Name FROM @test.data()";
 
         // Act
         var buildItems = CreateBuildItems<BasicEntity>(query);
@@ -410,7 +410,7 @@ public void Should_Execute_Query_With_Results()
     };
 
     // Act
-    var vm = CreateAndRunVirtualMachine("SELECT Name FROM #basic.entities()", data);
+    var vm = CreateAndRunVirtualMachine("SELECT Name FROM @basic.entities()", data);
     var table = vm.Run();
 
     // Assert

.copilot/api-usage-examples.md

@@ -16,7 +16,7 @@ using Musoq.Evaluator;
 using Musoq.Schema;
 
 // Basic query compilation and execution
-var query = "SELECT Name, Count(*) FROM #schema.source() GROUP BY Name";
+var query = "SELECT Name, Count(*) FROM @schema.source() GROUP BY Name";
 var schemaProvider = new MySchemaProvider();
 var loggerResolver = new LoggerResolver();
 
@@ -349,7 +349,7 @@ public class ParameterizedQueryExample
         // Use parameters to prevent injection and improve reusability
         var query = @"
             SELECT Name, CreatedAt, Status
-            FROM #system.events()
+            FROM @system.events()
             WHERE Name LIKE @userPattern
               AND CreatedAt BETWEEN @fromDate AND @toDate
             ORDER BY CreatedAt DESC";
@@ -418,9 +418,9 @@ var results = engine.ExecuteQuery(@"
         c.CustomerName,
         p.ProductName,
         o.Quantity * p.Price as TotalValue
-    FROM #sales.orders() o
-    INNER JOIN #users.customers() c ON o.CustomerId = c.Id
-    INNER JOIN #inventory.products() p ON o.ProductId = p.Id
+    FROM @sales.orders() o
+    INNER JOIN @users.customers() c ON o.CustomerId = c.Id
+    INNER JOIN @inventory.products() p ON o.ProductId = p.Id
     WHERE o.OrderDate >= '2023-01-01'
     ORDER BY TotalValue DESC");
 ```
@@ -456,7 +456,7 @@ public class StreamingQueryProcessor
 var processor = new StreamingQueryProcessor();
 
 await foreach (var row in processor.ExecuteStreamingQuery(
-    "SELECT * FROM #large.dataset() WHERE Status = 'Active'",
+    "SELECT * FROM @large.dataset() WHERE Status = 'Active'",
     schemaProvider,
     cancellationToken))
 {
@@ -670,7 +670,7 @@ public class ApiUsageTests
 
         var query = @"
             SELECT Department, COUNT(*) as EmployeeCount, AVG(Age) as AverageAge
-            FROM #test.table('employees')
+            FROM @test.table('employees')
             GROUP BY Department
             ORDER BY EmployeeCount DESC";
 

.copilot/development-debugging-guide.md

@@ -139,7 +139,7 @@ dotnet run --project Musoq.Benchmarks --configuration Release
 // Debug parser output
 public void DebugParseTree()
 {
-    var lexer = new Lexer("SELECT Name FROM #test.data()");
+    var lexer = new Lexer("SELECT Name FROM @test.data()");
     var parser = new Parser(lexer);
     var rootNode = parser.ComposeAll();
 
@@ -165,7 +165,7 @@ private void PrintAST(Node node, int depth)
 // Inspect generated C# code
 public void DebugCodeGeneration()
 {
-    var query = "SELECT Name, Count(*) FROM #test.data() GROUP BY Name";
+    var query = "SELECT Name, Count(*) FROM @test.data() GROUP BY Name";
     var buildItems = InstanceCreator.CreateForAnalyze(
         query, 
         Guid.NewGuid().ToString(), 
@@ -248,7 +248,7 @@ public class CustomParserTests
     public void Should_Parse_New_Syntax()
     {
         // Arrange
-        var query = "SELECT * FROM #new.syntax('param') WITH OPTIONS";
+        var query = "SELECT * FROM @new.syntax('param') WITH OPTIONS";
         var lexer = new Lexer(query);
         var parser = new Parser(lexer);
 
@@ -300,7 +300,7 @@ public class FullQueryIntegrationTests : BasicEntityTestBase
         var query = @"
             WITH processed AS (
                 SELECT Name, ProcessText(Description) as CleanText
-                FROM #test.data()
+                FROM @test.data()
             )
             SELECT Name, Count(*) as WordCount
             FROM processed

.copilot/plugin-development-guide.md

@@ -558,7 +558,7 @@ public class FileSystemSchemaIntegrationTests : BasicEntityTestBase
     {
         // Arrange
         var schemaProvider = new CustomSchemaProvider();
-        var query = "SELECT Name, Size FROM #fs.files('.', false) WHERE Extension = '.txt'";
+        var query = "SELECT Name, Size FROM @fs.files('.', false) WHERE Extension = '.txt'";
 
         // Act
         var compiledQuery = CreateAndRunVirtualMachine(query, schemaProvider: schemaProvider);

.github/copilot-instructions.md

@@ -109,7 +109,7 @@ Each module has corresponding test projects (*.Tests) with comprehensive coverag
 - **Common usage pattern**:
   ```csharp
   var compiledQuery = InstanceCreator.CompileForExecution(
-      "SELECT Name, Count(*) FROM #test.data() GROUP BY Name",
+      "SELECT Name, Count(*) FROM @test.data() GROUP BY Name",
       Guid.NewGuid().ToString(),
       schemaProvider,
       loggerResolver);

ARCHITECTURE.md

@@ -261,15 +261,15 @@ Query Engine ←→ Schema Interface ←→ Data Source Plugin ←→ External D
 ### 1. **Library Integration**
 ```csharp
 // Direct API usage
-var query = "SELECT * FROM #os.files('/path') WHERE Extension = '.txt'";
+var query = "SELECT * FROM @os.files('/path') WHERE Extension = '.txt'";
 var compiledQuery = MusoqQueryCompiler.Compile(query);
 var results = compiledQuery.Run();
 ```
 
 ### 2. **CLI Integration**
 ```bash
 # Command-line usage
-musoq "SELECT COUNT(*) FROM #git.commits('/repo')"
+musoq "SELECT COUNT(*) FROM @git.commits('/repo')"
 ```
 
 ### 3. **Plugin Development**

Musoq.Benchmarks/Components/ExecutionBenchmark.cs

@@ -53,25 +53,25 @@ public void Cleanup()
 
     private CompiledQuery CreateCompiledQueryWithOptions(CompilationOptions compilationOptions)
     {
-        var script = "select City, Country, Population from #A.Entities() where Population > 500000";
+        var script = "select City, Country, Population from @A.Entities() where Population > 500000";
         var contentPath = Path.Combine(AppContext.BaseDirectory, "Data", "countries.json");
         var data = DataHelpers.ParseCountryData(contentPath);
         var sources = new Dictionary<string, IEnumerable<CountryEntity>>
         {
-            {"#A", data}
+            {"@A", data}
         };
 
         return CreateForCountryWithOptions(script, sources, compilationOptions);
     }
 
     private CompiledQuery ComputeProfilesWithOptions(CompilationOptions compilationOptions)
     {
-        const string script = "select FirstName, LastName, Email, Gender, IpAddress, Date, Image, Animal, Avatar from #A.Entities() where Email like '%.co.uk'";
+        const string script = "select FirstName, LastName, Email, Gender, IpAddress, Date, Image, Animal, Avatar from @A.Entities() where Email like '%.co.uk'";
         var contentPath = Path.Combine(AppContext.BaseDirectory, "Data", "profiles.csv");
         var data = DataHelpers.ReadProfiles(contentPath);
         var sources = new Dictionary<string, IEnumerable<ProfileEntity>>
         {
-            {"#A", data}
+            {"@A", data}
         };
 
         return CreateForProfilesWithOptions(script, sources, compilationOptions);

Musoq.Converter.Tests/BuildTests.cs

@@ -13,7 +13,7 @@ public class BuildTests
     [TestMethod]
     public void CompileForStoreTest()
     {
-        var query = "select 1 from #system.dual()";
+        var query = "select 1 from @system.dual()";
 
         var (dllFile, pdbFile) = CreateForStore(query);
 
@@ -27,7 +27,7 @@ public void CompileForStoreTest()
     [TestMethod]
     public async Task CompileForStoreAsyncTest()
     {
-        var query = "select 1 from #system.dual()";
+        var query = "select 1 from @system.dual()";
 
         var arrays = await InstanceCreator.CompileForStoreAsync(query, Guid.NewGuid().ToString(), new SystemSchemaProvider(), new TestsLoggerResolver());
 

Musoq.Evaluator.Tests/AliasGeneratorQueryTests.cs

@@ -10,7 +10,7 @@ public class AliasGeneratorQueryTests : BasicEntityTestBase
     [TestMethod]
     public void WhenBuildMultipleTimes_AliasesShouldStayTheSame()
     {
-        const string query = "select 1 from #A.entities()";
+        const string query = "select 1 from @A.entities()";
 
         var firstBuild = CreateBuildItems<BasicEntity>(query);
         var secondBuild = CreateBuildItems<BasicEntity>(query);

Musoq.Evaluator.Tests/AliasTests.cs

@@ -12,7 +12,7 @@ public class AliasTests : MultiSchemaTestBase
     public void WhenUniqueColumnAcrossJoinedDataSetOccurred_ShouldNotNeedToUseAlias()
     {
         //ZeroItem doesn't need an alias as it is unique column within those two data sources
-        const string query = "select ZeroItem from #schema.first() first inner join #schema.second() second on 1 = 1";
+        const string query = "select ZeroItem from @schema.first() first inner join @schema.second() second on 1 = 1";
 
         var vm = CreateAndRunVirtualMachine(query, [
             new()
@@ -30,7 +30,7 @@ public void WhenUniqueColumnAcrossJoinedDataSetOccurred_ShouldNotNeedToUseAlias(
     [TestMethod]
     public void WhenNonExistingAliasUsed_ShouldThrow()
     {
-        const string query = "select b.ZeroItem from #schema.first() a";
+        const string query = "select b.ZeroItem from @schema.first() a";
 
         Assert.ThrowsException<UnknownColumnOrAliasException>(() => CreateAndRunVirtualMachine(query, [
             new()
@@ -43,7 +43,7 @@ public void WhenNonExistingAliasUsed_ShouldThrow()
     public void WhenAmbiguousColumnAcrossJoinedDataSetOccurred_ShouldNeedToUseAlias()
     {
         //FirstItem needs an alias as it is ambiguous column within those two data sources
-        const string query = "select first.FirstItem, second.FirstItem from #schema.first() first inner join #schema.second() second on 1 = 1";
+        const string query = "select first.FirstItem, second.FirstItem from @schema.first() first inner join @schema.second() second on 1 = 1";
 
         var vm = CreateAndRunVirtualMachine(query, [
             new()
@@ -68,8 +68,8 @@ with p as (
     select 
         first.FirstItem, 
         second.FirstItem 
-    from #schema.first() first 
-    inner join #schema.second() second on 1 = 1
+    from @schema.first() first 
+    inner join @schema.second() second on 1 = 1
 )
 select [first.FirstItem], [second.FirstItem] from p";
 
@@ -97,8 +97,8 @@ with p as (
         first.FirstItem, 
         second.FirstItem
     }
-    from #schema.first() first
-    inner join #schema.second() second on 1 = 1
+    from @schema.first() first
+    inner join @schema.second() second on 1 = 1
 )
 select p.[first.FirstItem], p.[second.FirstItem] from p";
 
@@ -125,8 +125,8 @@ with p as (
     select 
         first.FirstItem, 
         second.FirstItem
-    from #schema.first() first
-    inner join #schema.second() second on 1 = 1
+    from @schema.first() first
+    inner join @schema.second() second on 1 = 1
 ), q as (
     select p.[first.FirstItem] as FirstItem, p.[second.FirstItem] as SecondItem from p
 )
@@ -156,8 +156,8 @@ with p as (
         first.FirstItem, 
         second.FirstItem
     }
-    from #schema.first() first
-    inner join #schema.second() second on 1 = 1
+    from @schema.first() first
+    inner join @schema.second() second on 1 = 1
 ), q as (
     select p.[first.FirstItem], p.[second.FirstItem] from p
 )
@@ -184,12 +184,12 @@ public void WhenAliasUsedWithinCte_AndSameUsedWithinOuterQuery_AliasesShouldNotC
 with p as (
     select 
         1 
-    from #schema.first() first
+    from @schema.first() first
     cross apply first.Split('') b
 )
 select 
     1 
-from p inner join #schema.first() first on 1 = 1
+from p inner join @schema.first() first on 1 = 1
 cross apply first.Split('') b";
 
         var vm = CreateAndRunVirtualMachine(query, [
@@ -208,7 +208,7 @@ cross apply first.Split('') b
     [TestMethod]
     public void WhenSameAliasUsedInFromAndJoin_ShouldThrow()
     {
-        const string query = "select a.FirstItem from #schema.first() a inner join #schema.second() a on a.FirstItem = a.FirstItem";
+        const string query = "select a.FirstItem from @schema.first() a inner join @schema.second() a on a.FirstItem = a.FirstItem";
 
         Assert.ThrowsException<AliasAlreadyUsedException>(() => CreateAndRunVirtualMachine(query, [
             new(),
@@ -224,9 +224,9 @@ public void WhenSameAliasUsedInMultipleJoins_ShouldThrow()
     {
         const string query = @"
             select src.FirstItem 
-            from #schema.first() src 
-            inner join #schema.second() b on src.FirstItem = b.FirstItem
-            inner join #schema.third() b on b.FirstItem = src.FirstItem";
+            from @schema.first() src 
+            inner join @schema.second() b on src.FirstItem = b.FirstItem
+            inner join @schema.third() b on b.FirstItem = src.FirstItem";
 
         Assert.ThrowsException<AliasAlreadyUsedException>(() => CreateAndRunVirtualMachine(query, [
             new(),
@@ -244,10 +244,10 @@ public void WhenSameAliasUsedInCTEAndMainQuery_ShouldThrow()
     {
         const string query = @"
             with src as (
-                select FirstItem from #schema.first()
+                select FirstItem from @schema.first()
             )
             select src.FirstItem 
-            from #schema.second() src
+            from @schema.second() src
             inner join src on src.FirstItem = src.FirstItem";
 
         Assert.ThrowsException<AliasAlreadyUsedException>(() => CreateAndRunVirtualMachine(query, [
@@ -264,8 +264,8 @@ public void WhenSameAliasUsedInCrossApply_ShouldThrow()
     {
         const string query = @"
             select a.FirstItem 
-            from #schema.first() a 
-            cross apply #schema.second() a";
+            from @schema.first() a 
+            cross apply @schema.second() a";
 
         Assert.ThrowsException<AliasAlreadyUsedException>(() => CreateAndRunVirtualMachine(query, [
             new(),
@@ -281,8 +281,8 @@ public void WhenSameAliasUsedInOuterApply_ShouldThrow()
     {
         const string query = @"
             select a.FirstItem 
-            from #schema.first() a 
-            outer apply #schema.second() a";
+            from @schema.first() a 
+            outer apply @schema.second() a";
 
         Assert.ThrowsException<AliasAlreadyUsedException>(() => CreateAndRunVirtualMachine(query, [
             new(),