fix: remove remaining anonymous namespaces for unity build compat

AGENTS.md

@@ -98,6 +98,30 @@ serialization/deserialization libraries. See:
 What you need to know right now is that `gen/cpp` is where our MusicXML types are coming from. Run
 `make gen-cpp` to regenerate the C++ types.
 
+## C++ coding rules
+
+Do not use anonymous namespaces (`namespace { }`) anywhere in the codebase. All symbols must be in
+a named namespace. Anonymous namespaces give internal linkage, which is correct for a normal
+one-TU-per-file build but causes redefinition errors in unity builds (where multiple `.cpp` files
+are compiled as a single translation unit). Use a named helper function or per-type name instead:
+
+- For file-local helper functions: name them after the type or file, e.g. `tokenIsNameChar`,
+  `clampedTenths`.
+- For file-local constants (arrays, string_views): use a per-type prefix, e.g. `kYesNoWire`,
+  `kSmuflAccidentalGlyphNamePrefix`.
+- In code generator templates (`gen/cpp/templates/`): use `{{ident}}` to make names unique, e.g.
+  `k{{ident}}Wire`, `isNameChar{{ident}}`.
+
+Unity builds can be tested with CMake's built-in support — no changes to `CMakeLists.txt` are
+needed by contributors. To verify, configure with:
+
+```
+cmake -S . -B build/unity -DCMAKE_UNITY_BUILD=ON -DCMAKE_UNITY_BUILD_BATCH_SIZE=0
+cmake --build build/unity --target mx
+```
+
+`BATCH_SIZE=0` puts all files in a target into one translation unit, which is the strictest test.
+
 ## Quality gates
 
 Run `make fmt` to format. `make check` is the clang-format gate **only** — it builds and tests nothing.

gen/cpp/templates/nmtoken_string.cpp.tmpl

@@ -7,18 +7,13 @@
 namespace {{vars.namespace}}
 {
 
-namespace
-{
-
 // The ASCII subset of XML name characters (matches the schema's \c).
-bool isNameChar(char c) noexcept
+bool isNameChar{{ident}}(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' ||
            c == '.' || c == ':' || c == '_';
 }
 
-} // namespace
-
 {{ident}}::{{ident}}()
 {
     repair();
@@ -41,7 +36,7 @@ void {{ident}}::repair()
     cleaned.reserve(m_value.size());
     for (const char c : m_value)
     {
-        if (isNameChar(c))
+        if (isNameChar{{ident}}(c))
         {
             cleaned.push_back(c);
         }
@@ -61,7 +56,7 @@ bool {{ident}}::tryParse(std::string_view text, {{ident}} &out)
     }
     for (const char c : text)
     {
-        if (!isNameChar(c))
+        if (!isNameChar{{ident}}(c))
         {
             return false;
         }

gen/cpp/templates/smufl_wavy.cpp.tmpl

@@ -7,22 +7,17 @@
 namespace {{vars.namespace}}
 {
 
-namespace
-{
-
 constexpr std::string_view kWiggle = "wiggle";
 constexpr std::string_view kGuitar = "guitar";
 constexpr std::string_view kVibratoStroke = "VibratoStroke";
 
 // The ASCII subset of XML name characters the schema's \c denotes.
-bool isNameChar(char c) noexcept
+bool isNameChar{{ident}}(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' ||
            c == '.' || c == ':' || c == '_';
 }
 
-} // namespace
-
 {{ident}}::{{ident}}()
 {
     repair();
@@ -55,7 +50,7 @@ void {{ident}}::repair()
     cleaned.reserve(m_part.size());
     for (const char c : m_part)
     {
-        if (isNameChar(c))
+        if (isNameChar{{ident}}(c))
         {
             cleaned.push_back(c);
         }
@@ -86,7 +81,7 @@ bool {{ident}}::tryParse(std::string_view text, {{ident}} &out)
     const auto allNameChars = [](std::string_view s) {
         for (const char c : s)
         {
-            if (!isNameChar(c))
+            if (!isNameChar{{ident}}(c))
             {
                 return false;
             }

src/private/mx/core/NameToken.cpp

@@ -9,17 +9,12 @@
 namespace mx::core
 {
 
-namespace
-{
-
-bool isNameChar(char c) noexcept
+bool nameTokenIsNameChar(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' || c == '.' ||
            c == ':' || c == '_';
 }
 
-} // namespace
-
 NameToken::NameToken()
 {
     repair();
@@ -42,7 +37,7 @@ void NameToken::repair()
     cleaned.reserve(m_value.size());
     for (const char c : m_value)
     {
-        if (isNameChar(c))
+        if (nameTokenIsNameChar(c))
         {
             cleaned.push_back(c);
         }
@@ -62,7 +57,7 @@ bool NameToken::tryParse(std::string_view text, NameToken &out)
     }
     for (const char c : text)
     {
-        if (!isNameChar(c))
+        if (!nameTokenIsNameChar(c))
         {
             return false;
         }

src/private/mx/core/Token.cpp

@@ -9,24 +9,19 @@
 namespace mx::core
 {
 
-namespace
-{
-
 // The ASCII subset of the XML NCName character classes (the schema's
 // vocabularies are ASCII; the strict parse is the only consumer, so the
 // approximation can only under-accept).
-bool isNameStart(char c) noexcept
+bool tokenIsNameStart(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_';
 }
 
-bool isNameChar(char c) noexcept
+bool tokenIsNameChar(char c) noexcept
 {
-    return isNameStart(c) || (c >= '0' && c <= '9') || c == '-' || c == '.';
+    return tokenIsNameStart(c) || (c >= '0' && c <= '9') || c == '-' || c == '.';
 }
 
-} // namespace
-
 Token::Token()
 {
     repair();
@@ -49,14 +44,14 @@ void Token::repair()
     cleaned.reserve(m_value.size());
     for (const char c : m_value)
     {
-        if (isNameChar(c))
+        if (tokenIsNameChar(c))
         {
             cleaned.push_back(c);
         }
     }
     // An NCName cannot begin with a digit, '-', or '.'.
     std::size_t start = 0;
-    while (start < cleaned.size() && !isNameStart(cleaned[start]))
+    while (start < cleaned.size() && !tokenIsNameStart(cleaned[start]))
     {
         ++start;
     }
@@ -70,13 +65,13 @@ void Token::repair()
 
 bool Token::tryParse(std::string_view text, Token &out)
 {
-    if (text.empty() || !isNameStart(text.front()))
+    if (text.empty() || !tokenIsNameStart(text.front()))
     {
         return false;
     }
     for (const char c : text)
     {
-        if (!isNameChar(c))
+        if (!tokenIsNameChar(c))
         {
             return false;
         }

src/private/mx/core/generated/SmuflGlyphName.cpp

@@ -7,18 +7,13 @@
 namespace mx::core
 {
 
-namespace
-{
-
 // The ASCII subset of XML name characters (matches the schema's \c).
-bool isNameChar(char c) noexcept
+bool isNameCharSmuflGlyphName(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' || c == '.' ||
            c == ':' || c == '_';
 }
 
-} // namespace
-
 SmuflGlyphName::SmuflGlyphName()
 {
     repair();
@@ -41,7 +36,7 @@ void SmuflGlyphName::repair()
     cleaned.reserve(m_value.size());
     for (const char c : m_value)
     {
-        if (isNameChar(c))
+        if (isNameCharSmuflGlyphName(c))
         {
             cleaned.push_back(c);
         }
@@ -61,7 +56,7 @@ bool SmuflGlyphName::tryParse(std::string_view text, SmuflGlyphName &out)
     }
     for (const char c : text)
     {
-        if (!isNameChar(c))
+        if (!isNameCharSmuflGlyphName(c))
         {
             return false;
         }

src/private/mx/core/generated/SmuflWavyLineGlyphName.cpp

@@ -7,22 +7,17 @@
 namespace mx::core
 {
 
-namespace
-{
-
 constexpr std::string_view kWiggle = "wiggle";
 constexpr std::string_view kGuitar = "guitar";
 constexpr std::string_view kVibratoStroke = "VibratoStroke";
 
 // The ASCII subset of XML name characters the schema's \c denotes.
-bool isNameChar(char c) noexcept
+bool isNameCharSmuflWavyLineGlyphName(char c) noexcept
 {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' || c == '.' ||
            c == ':' || c == '_';
 }
 
-} // namespace
-
 SmuflWavyLineGlyphName::SmuflWavyLineGlyphName()
 {
     repair();
@@ -55,7 +50,7 @@ void SmuflWavyLineGlyphName::repair()
     cleaned.reserve(m_part.size());
     for (const char c : m_part)
     {
-        if (isNameChar(c))
+        if (isNameCharSmuflWavyLineGlyphName(c))
         {
             cleaned.push_back(c);
         }
@@ -86,7 +81,7 @@ bool SmuflWavyLineGlyphName::tryParse(std::string_view text, SmuflWavyLineGlyphN
     const auto allNameChars = [](std::string_view s) {
         for (const char c : s)
         {
-            if (!isNameChar(c))
+            if (!isNameCharSmuflWavyLineGlyphName(c))
             {
                 return false;
             }