Merge pull request #322 from fglock/fix/mo-bareword-parsing

Fix ::identifier bareword parsing and jcpan cpan script

Author: fglock

.gitignore

@@ -13,6 +13,8 @@ target/
 .java-version
 build/
 bin/
+# But allow Perl bin scripts
+!src/main/perl/bin/
 gradle/*
 !gradle/libs.versions.toml
 gradlew

dev/design/moo_support.md

@@ -589,11 +589,34 @@ Moo tests run via `jcpan -t Moo`. Recent fixes (Phases 12-13) should improve pas
   - This fixes Sub::Quote's `local @_ = ($value)` inlinification pattern
   - Fixes t/method-generate-accessor.t (46/49 → 49/49)
 
+- [x] Phase 24: Fix ::identifier bareword parsing (2026-03-16)
+  - Root cause: `::foo` without parens was always treated as `main::foo` identifier
+  - In Perl: `::foo` calls main::foo only if sub exists at compile time, else bareword string
+  - Mo uses `$M.$_.::e` to build package names - `::e` should be bareword string
+  - But tests use `::is ::exception { }` where `is` and `exception` are imported subs
+  - **ParsePrimary.java fix**:
+    - Check `GlobalVariable.getGlobalCodeRef(fullSubName).getDefinedBoolean()`
+    - If sub exists OR followed by `(`: function call (main::identifier)
+    - If sub doesn't exist AND no parens: bareword string ('::identifier')
+  - **config.yaml fix**: Added cpan script to sync config for jcpan wrapper
+  - **.gitignore fix**: Allow src/main/perl/bin/ directory in git
+  - Mo tests: 27/28 passing (99.3%)
+
+- [x] Phase 25: Fix self-referential hash assignment (2026-03-16)
+  - Root cause: `%h = (new_stuff, %h)` was clearing hash before evaluating `%h`
+  - Mo uses: `%e = (extends => sub{...}, has => sub{...}, %e)` to merge exports
+  - The hash was cleared before iterating over the RHS list containing `%h`
+  - **RuntimeHash.java fix**:
+    - Materialize entire RHS list into temporary array BEFORE clearing hash
+    - Similar to how tied hashes are already handled
+  - This fixed Mo's BUILD feature which depends on the %e merge pattern
+  - Mo tests: 6/28 failing → 1/28 failing (143/144 subtests pass)
+
 ### Current Status
 
-**Test Results (after Phase 23):**
-- 62/71 test programs passing (87%)
-- ~768/829 subtests passing (93%)
+**Test Results (after Phase 25):**
+- **Moo**: 62/71 test programs passing (87%), 768/829 subtests passing (93%)
+- **Mo**: 27/28 test programs passing (99.3%), 143/144 subtests passing
 
 **Remaining Failures (categorized):**
 1. **accessor-weaken tests** (20 failures) - Expected, weak references not supported in Java GC
@@ -602,6 +625,7 @@ Moo tests run via `jcpan -t Moo`. Recent fixes (Phases 12-13) should improve pas
 4. **moo-utils-_subname-Sub-Name.t** (1 failure) - Expected, we have Sub::Util (no fallback to Sub::Name)
 5. **no-moo.t** (5 failures) - Namespace cleanup requires weak references
 6. **overloaded-coderefs.t** - Expected, B::Deparse not available
+7. **Mo t/strict.t** (1 failure) - Error message format differs from Perl
 
 **Expected failures** (not fixable without fundamental changes):
 - Weak references: accessor-weaken tests (20), no-moo.t cleanup (5)
@@ -621,12 +645,16 @@ Moo tests run via `jcpan -t Moo`. Recent fixes (Phases 12-13) should improve pas
 ### PR Information
 - **Branch**: `feature/moo-support` (PR #319 - merged)
 - **Branch**: `fix/goto-tailcall-import` (PR #320 - open)
+- **Branch**: `fix/mo-bareword-parsing` (PR #322 - open)
 - **Key commits**:
   - `00c124167` - Fix print { func() } filehandle block parsing and JVM codegen
   - `393bedf0f` - Fix quotemeta and Package::SUPER::method resolution
   - `7a76739b8` - Fix goto &sub in use/import TAILCALL handling
   - `053d91a95` - Add Sub::Util, fix Scalar/List::Util VERSION, add Test::Harness
   - `7993ef74d` - Fix version parsing and MM->parse_version for CPAN.pm
+  - `db434f8d3` - Fix ::identifier bareword parsing and add cpan to sync
+  - `ff31163f9` - Fix self-referential hash assignment %h = (stuff, %h)
+  - `a3233cd55` - Improve ::identifier to check sub existence at compile time
 
 ## Related Documents
 

dev/import-perl5/config.yaml

@@ -27,6 +27,10 @@ imports:
   - source: perl5/dist/Carp/lib/Carp/Heavy.pm
     target: src/main/perl/lib/Carp/Heavy.pm
 
+  # CPAN client script - required by jcpan wrapper
+  - source: perl5/cpan/CPAN/scripts/cpan
+    target: src/main/perl/bin/cpan
+
   - source: perl5/lib/Benchmark.pm
     target: src/main/perl/lib/Benchmark.pm
 

src/main/java/org/perlonjava/frontend/parser/ParsePrimary.java

@@ -269,15 +269,42 @@ static Node parseOperator(Parser parser, LexerToken token, String operator) {
                 return StringParser.parseRawString(parser, token.text);
 
             case "::":
-                // Leading :: means main:: (e.g., ::foo is main::foo)
-                // This allows accessing global variables even when a lexical exists
+                // Leading :: can mean either:
+                // 1. Function call: ::foo() -> main::foo()
+                // 2. Bareword reference: ::foo without parens -> calls main::foo if it exists
+                // 3. Bareword string: ::foo when no such sub exists -> '::foo'
+                //
+                // In Perl, ::foo without parens calls main::foo if the sub exists at compile time.
+                // If no such sub exists, it becomes a bareword string '::foo'.
                 LexerToken nextToken2 = peek(parser);
                 if (nextToken2.type == LexerTokenType.IDENTIFIER) {
-                    // Insert "main" before the :: to create main::identifier
-                    parser.tokens.add(parser.tokenIndex - 1, new LexerToken(LexerTokenType.IDENTIFIER, "main"));
-                    parser.tokenIndex--; // Go back to process "main"
-                    return parseIdentifier(parser, parser.tokenIndex,
-                            new LexerToken(LexerTokenType.IDENTIFIER, "main"), "main");
+                    String identifierName = nextToken2.text;
+                    // Look ahead to see if this is a function call with parens
+                    int lookAhead = parser.tokenIndex + 1;
+                    // Skip whitespace
+                    while (lookAhead < parser.tokens.size() && 
+                           parser.tokens.get(lookAhead).type == LexerTokenType.WHITESPACE) {
+                        lookAhead++;
+                    }
+                    String afterIdentifier = lookAhead < parser.tokens.size() ? 
+                                            parser.tokens.get(lookAhead).text : "";
+                    
+                    // Check if the sub exists at compile time
+                    String fullSubName = "main::" + identifierName;
+                    boolean subExists = GlobalVariable.getGlobalCodeRef(fullSubName).getDefinedBoolean();
+                    
+                    if (afterIdentifier.equals("(") || subExists) {
+                        // Function call: ::foo() or ::foo (when sub exists)
+                        // Insert "main" before the :: to create main::identifier
+                        parser.tokens.add(parser.tokenIndex - 1, new LexerToken(LexerTokenType.IDENTIFIER, "main"));
+                        parser.tokenIndex--; // Go back to process "main"
+                        return parseIdentifier(parser, parser.tokenIndex,
+                                new LexerToken(LexerTokenType.IDENTIFIER, "main"), "main");
+                    } else {
+                        // Bareword: ::foo -> '::foo' (no such sub exists)
+                        parser.tokenIndex++; // Consume the identifier
+                        return new StringNode("::" + identifierName, parser.tokenIndex);
+                    }
                 }
                 throw new PerlCompilerException(parser.tokenIndex, "syntax error", parser.ctx.errorUtil);
 

src/main/java/org/perlonjava/runtime/runtimetypes/RuntimeHash.java

@@ -189,23 +189,18 @@ public RuntimeScalar addToScalar(RuntimeScalar scalar) {
     public RuntimeArray setFromList(RuntimeList value) {
         return switch (type) {
             case PLAIN_HASH -> {
-                // Store the original list size for scalar context
-                int originalSize = 0;
-                for (RuntimeBase elem : value.elements) {
-                    if (elem instanceof RuntimeArray) {
-                        originalSize += ((RuntimeArray) elem).elements.size();
-                    } else if (elem instanceof RuntimeScalar) {
-                        originalSize++;
-                    } else {
-                        // Count elements by iterating
-                        Iterator<RuntimeScalar> it = elem.iterator();
-                        while (it.hasNext()) {
-                            it.next();
-                            originalSize++;
-                        }
-                    }
+                // First, fully materialize the right-hand side list BEFORE clearing
+                // This is critical for self-referential assignments like: %h = (new_stuff, %h)
+                // We must capture the current hash contents before clearing.
+                RuntimeArray materializedList = new RuntimeArray();
+                Iterator<RuntimeScalar> iterator = value.iterator();
+                while (iterator.hasNext()) {
+                    materializedList.push(new RuntimeScalar(iterator.next()));
                 }
 
+                // Store the original list size for scalar context
+                int originalSize = materializedList.elements.size();
+
                 // Warn about odd elements (Perl does not warn about references in hash assignment)
                 if (originalSize % 2 != 0) {
                     WarnDie.warn(
@@ -216,13 +211,12 @@ public RuntimeArray setFromList(RuntimeList value) {
                 // Clear existing elements but keep the same Map instance to preserve capacity
                 this.elements.clear();
 
-                // Populate the hash from the provided list
-                // This reuses the existing StableHashMap and its capacity
-                Iterator<RuntimeScalar> iter = value.iterator();
-                while (iter.hasNext()) {
-                    String key = iter.next().toString();
+                // Populate the hash from the materialized list
+                iterator = materializedList.iterator();
+                while (iterator.hasNext()) {
+                    String key = iterator.next().toString();
                     // Create a new RuntimeScalar to properly handle aliasing and avoid read-only issues
-                    RuntimeScalar val = iter.hasNext() ? new RuntimeScalar(iter.next()) : new RuntimeScalar();
+                    RuntimeScalar val = iterator.hasNext() ? new RuntimeScalar(iterator.next()) : new RuntimeScalar();
                     this.elements.put(key, val);
                 }