add vars pragma

Author: fglock

FEATURE_MATRIX.md

@@ -282,6 +282,7 @@
 - ✔️   **constant** pragma
 - ✔️   **if** pragma
 - ✔️   **lib** pragma
+- ✔️   **vars** pragma
 - 🚧  **utf8** pragma: utf8 is always on. Disabling utf8 might work in a future version.
 - ✔️   **feature** pragma
   - ✔️  Features implemented: `fc`, `say`, `current_sub`, `isa`, `state`, `try`, `bitwise`, `postderef`.

MILESTONES.md

@@ -101,13 +101,14 @@
 - **v1.12.0**: Concurrency and Security Features
   - Planned release date: 2024-12-10
   - Added unmodified core Perl modules `File::Basename`, `File::Find`, `Data::Dumper`, `Term::ANSIColor`, `Time::Local`, `HTTP::Date`, `HTTP::CookieJar`.
-  - Added `Cwd`, `File::Spec`, `File::Spec::Functions` modules.
+  - Added `Cwd`, `File::Spec`, `File::Spec::Functions`, `HTTP::Tiny` modules.
   - "use feature" implemented: `fc`, `say`, `current_sub`, `isa`, `state`, `try`, `bitwise`, `postderef`.
   - Stash can be accessed as a hash like `$namespace::{entry}`.
   - Added stash constants:  `$constant::{_CAN_PCS} = \$const`;
   - Added `exists &sub`, `defined &sub`.
   - Added `builtin` pragma: `true`, `false`, `is_bool`.
   - Added `re` pragma: `is_regexp`.
+  - Added `vars` pragma.
   - Added `SUPER::method` method resolution.
   - Added `AUTOLOAD` default subroutine.
   - Added `stat`, `lstat` operators. Some fields are not available in JVM and return `undef`.
@@ -123,11 +124,10 @@
     - lexical utf8 source code.
     - `truncate`, `seek` operators.
     - preprocessor `# line` directive.
-    - `use subs`, `use vars`.
+    - `use subs`.
     - `Getopt::Long`.
     - subroutine prototypes.
     - `JSON` module.
-    - `HTTP::Tiny` module.
   - Stretch goals
     - Add support for concurrency and parallelism, such as threads and async/await.
     - Enhance security features, including sandboxing and input validation.

src/main/java/org/perlonjava/perlmodule/Vars.java

@@ -0,0 +1,62 @@
+package org.perlonjava.perlmodule;
+
+import org.perlonjava.runtime.*;
+
+/**
+ * The Vars class is responsible for creating variables in the current package.
+ * It mimics the behavior of Perl's vars module, allowing variables to be declared.
+ */
+public class Vars extends PerlModuleBase {
+
+    public Vars() {
+        super("vars");
+    }
+
+    /**
+     * Static initializer to set up the Vars module.
+     */
+    public static void initialize() {
+        Vars vars = new Vars();
+        try {
+            vars.registerMethod("import", "importVars", ";$");
+        } catch (NoSuchMethodException e) {
+            System.err.println("Warning: Missing vars method: " + e.getMessage());
+        }
+    }
+
+    /**
+     * Creates the specified variables in the current package.
+     *
+     * @param args The arguments specifying the variables to create.
+     * @param ctx  The context in which the variables are being created.
+     * @return A RuntimeList representing the result of the variable creation.
+     * @throws PerlCompilerException if there are issues with the variable creation process.
+     */
+    public static RuntimeList importVars(RuntimeArray args, int ctx) {
+        args.shift();
+
+        // Determine the caller's namespace
+        RuntimeList callerList = RuntimeScalar.caller(new RuntimeList(), RuntimeContextType.SCALAR);
+        String caller = callerList.scalar().toString();
+
+        // Create the specified variables in the caller's namespace
+        for (RuntimeScalar variableObj : args.elements) {
+            String variableString = variableObj.toString();
+
+            if (variableString.startsWith("$")) {
+                // Create a scalar variable
+                GlobalVariable.getGlobalVariable(caller + "::" + variableString.substring(1));
+            } else if (variableString.startsWith("@")) {
+                // Create an array variable
+                GlobalVariable.getGlobalArray(caller + "::" + variableString.substring(1));
+            } else if (variableString.startsWith("%")) {
+                // Create a hash variable
+                GlobalVariable.getGlobalHash(caller + "::" + variableString.substring(1));
+            } else {
+                throw new PerlCompilerException("Invalid variable type: " + variableString);
+            }
+        }
+
+        return new RuntimeList();
+    }
+}

src/main/java/org/perlonjava/runtime/GlobalContext.java

@@ -98,6 +98,7 @@ public static void initializeGlobals(ArgumentParser.CompilerOptions compilerOpti
         // Initialize built-in Perl classes
         DiamondIO.initialize(compilerOptions);
         Universal.initialize();
+        Vars.initialize();
         Builtin.initialize();
         Exporter.initialize();
         Base.initialize();