JSONValue / Container (#1864)

* #include an absolute path didn't work - because paths were taken to always be relative.

* WIP JSONWriter/JSONParser.

* Checking different Layout styles for JSON.

* Add slang-json-parser.h/.cpp

* WIP JSONValue.

* Added JSONValue::destroy/Recursive.

* Improvement to JSONValue.

* Improve text double conversion precision. Testing.

* Simplify double parsing (just use atof).
JSON comparison
More testing of conversions and start of JSONValue.

* Add <math.h> for isnan, isinf etc.

* Small improvement with object comparison.

* Fix typo in getArgsByName.

* Removed use of isnan and isinf as includes don't work on linux.

* Improve JSON unit test.

* Added asInteger/asFloat/asBool to JSONValue.

* Change comment to trigger CI build.

4 files changed, 1058 insertions, 4 deletions

diff --git a/source/compiler-core/slang-command-line-args.cpp b/source/compiler-core/slang-command-line-args.cpp
index d7a053b00..ec03e3116 100644
--- a/source/compiler-core/slang-command-line-args.cpp
+++ b/source/compiler-core/slang-command-line-args.cpp
@@ -171,14 +171,14 @@ Index DownstreamArgs::_findOrAddName(SourceLoc loc, const UnownedStringSlice& na
     return -1;
 }
 
-CommandLineArgs& DownstreamArgs::getArgsByName(char* name)
+CommandLineArgs& DownstreamArgs::getArgsByName(const char* name)
 {
     const Index index = findName(name);
     SLANG_ASSERT(index >= 0);
     return m_entries[index].args;
 }
 
-const CommandLineArgs& DownstreamArgs::getArgsByName(char* name) const
+const CommandLineArgs& DownstreamArgs::getArgsByName(const char* name) const
 {
     const Index index = findName(name);
     SLANG_ASSERT(index >= 0);
diff --git a/source/compiler-core/slang-command-line-args.h b/source/compiler-core/slang-command-line-args.h
index c18996005..31807cd48 100644
--- a/source/compiler-core/slang-command-line-args.h
+++ b/source/compiler-core/slang-command-line-args.h
@@ -147,8 +147,8 @@ struct DownstreamArgs
         /// Get the args at the nameIndex
     CommandLineArgs& getArgsAt(Index nameIndex) { return m_entries[nameIndex].args; }
         /// Get args by name - will assert if name isn't found
-    CommandLineArgs& getArgsByName(char* name);
-    const CommandLineArgs& getArgsByName(char* name) const;
+    CommandLineArgs& getArgsByName(const char* name);
+    const CommandLineArgs& getArgsByName(const char* name) const;
 
         /// Looks for '-X' expressions, removing them from ioArgs and putting in appropriate args 
     SlangResult stripDownstreamArgs(CommandLineArgs& ioArgs, Flags flags, DiagnosticSink* sink);
diff --git a/source/compiler-core/slang-json-value.cpp b/source/compiler-core/slang-json-value.cpp
new file mode 100644
index 000000000..3b74c00dd
--- /dev/null
+++ b/source/compiler-core/slang-json-value.cpp
@@ -0,0 +1,811 @@
+// slang-json-value.cpp
+#include "slang-json-value.h"
+
+#include "../core/slang-string-escape-util.h"
+#include "../core/slang-string-util.h"
+
+namespace Slang {
+
+/* static */const JSONValue::Kind JSONValue::g_typeToKind[] =
+{
+    JSONValue::Kind::Invalid,           // Invalid
+
+    JSONValue::Kind::Bool,              // True,
+    JSONValue::Kind::Bool,              // False
+    JSONValue::Kind::Null,              // Null,
+
+    JSONValue::Kind::String,            // StringLexeme,
+    JSONValue::Kind::Integer,           // IntegerLexeme,
+    JSONValue::Kind::Float,             // FloatLexeme,
+
+    JSONValue::Kind::Integer,           // IntegerValue,
+    JSONValue::Kind::Float,             // FloatValue,
+    JSONValue::Kind::String,            // StringValue,
+
+    JSONValue::Kind::Array,             // Array,
+    JSONValue::Kind::Object,            // Object,
+};
+
+static JSONKeyValue _makeInvalidKeyValue()
+{
+    JSONKeyValue keyValue;
+    keyValue.key = JSONKey(0);
+    keyValue.value.type = JSONValue::Type::Invalid;
+    return keyValue;
+}
+
+/* static */JSONKeyValue g_invalid = _makeInvalidKeyValue();
+
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+                             JSONValue
+
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
+
+bool JSONValue::asBool() const
+{
+    switch (type)
+    {
+        case JSONValue::Type::True:             return true;
+        case JSONValue::Type::False:
+        case JSONValue::Type::Null:
+        {
+            return false;
+        }
+        case JSONValue::Type::IntegerValue:     return intValue != 0;
+        case JSONValue::Type::FloatValue:       return floatValue != 0;
+        default: break;
+    }
+
+    if (isLexeme(type))
+    {
+        SLANG_ASSERT(!"Lexeme values can only be accessed through container");
+    }
+    else
+    {
+        SLANG_ASSERT(!"Not bool convertable");
+    }
+   
+    return false;
+}
+
+int64_t JSONValue::asInteger() const
+{
+    switch (type)
+    {
+        case JSONValue::Type::True:             return 1;
+        case JSONValue::Type::False:
+        case JSONValue::Type::Null:
+        {
+            return 0;
+        }
+        case JSONValue::Type::IntegerValue:     return intValue;
+        case JSONValue::Type::FloatValue:       return int64_t(floatValue);
+        break;
+    }
+
+    if (isLexeme(type))
+    {
+        SLANG_ASSERT(!"Lexeme values can only be accessed through container");
+    }
+    else
+    {
+        SLANG_ASSERT(!"Not int convertable");
+    }
+
+    return 0;
+}
+
+double JSONValue::asFloat() const
+{
+    switch (type)
+    {
+        case JSONValue::Type::True:             return 1.0;
+        case JSONValue::Type::False:
+        case JSONValue::Type::Null:
+        {
+            return 0.0;
+        }
+        case JSONValue::Type::IntegerValue:     return double(intValue);
+        case JSONValue::Type::FloatValue:       return floatValue;
+        default: break;
+    }
+
+    if (isLexeme(type))
+    {
+        SLANG_ASSERT(!"Lexeme values can only be accessed through container");
+    }
+    else
+    {
+        SLANG_ASSERT(!"Not float convertable");
+    }
+  
+    return 0;
+}
+
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+                             JSONContainer
+
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
+
+JSONContainer::JSONContainer(SourceManager* sourceManager):
+    m_slicePool(StringSlicePool::Style::Default),
+    m_sourceManager(sourceManager)
+{
+    // Index 0 is the empty array or object
+    _addRange(Range::Type::None, 0, 0);
+}
+
+/* static */bool JSONContainer::areKeysUnique(const JSONKeyValue* keyValues, Index keyValueCount)
+{
+    for (Index i = 1; i < keyValueCount; ++i)
+    {
+        const JSONKey key = keyValues[i].key;
+
+        for (Int j = 0; j < i - 1; j++)
+        {
+            if (keyValues[j].key == key)
+            {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+Index JSONContainer::_addRange(Range::Type type, Index startIndex, Index count)
+{
+    if (m_freeRangeIndices.getCount() > 0)
+    {
+        const Index rangeIndex = m_freeRangeIndices.getLast();
+        m_freeRangeIndices.removeLast();
+
+        auto& range = m_ranges[rangeIndex];
+        range.type = type;
+        range.startIndex = startIndex;
+        range.count = count;
+        range.capacity = count;
+
+        return rangeIndex;
+    }
+    else
+    {
+        Range range;
+        range.type = type;
+        range.startIndex = startIndex;
+        range.count = count;
+        range.capacity = count;
+
+        m_ranges.add(range);
+        return m_ranges.getCount() - 1;
+    }
+}
+
+JSONValue JSONContainer::createArray(const JSONValue* values, Index valuesCount, SourceLoc loc)
+{
+    if (valuesCount <= 0)
+    {
+        return JSONValue::makeEmptyArray(loc);
+    }
+
+    JSONValue value;
+    value.type = JSONValue::Type::Array;
+    value.loc = loc;
+    value.rangeIndex = _addRange(Range::Type::Array, m_objectValues.getCount(), valuesCount);
+
+    m_arrayValues.addRange(values, valuesCount);
+    return value;
+}
+
+JSONValue JSONContainer::createObject(const JSONKeyValue* keyValues, Index keyValueCount, SourceLoc loc)
+{
+    if (keyValueCount <= 0)
+    {
+        return JSONValue::makeEmptyObject(loc);
+    }
+
+    JSONValue value;
+    value.type = JSONValue::Type::Object;
+    value.loc = loc;
+    value.rangeIndex = _addRange(Range::Type::Object, m_objectValues.getCount(), keyValueCount);
+
+    m_objectValues.addRange(keyValues, keyValueCount);
+    return value;
+}
+
+JSONValue JSONContainer::createString(const UnownedStringSlice& slice, SourceLoc loc)
+{
+    JSONValue value;
+    value.type = JSONValue::Type::StringValue;
+    value.loc = loc;
+    value.stringKey = getKey(slice);
+    return value;
+}
+
+JSONKey JSONContainer::getKey(const UnownedStringSlice& slice)
+{
+    return JSONKey(m_slicePool.add(slice));
+}
+
+ConstArrayView<JSONValue> JSONContainer::getArray(const JSONValue& in) const
+{
+    SLANG_ASSERT(in.type == JSONValue::Type::Array);
+    if (in.type != JSONValue::Type::Array || in.rangeIndex == 0)
+    {
+        return ConstArrayView<JSONValue>((const JSONValue*)nullptr, 0);
+    }
+    const Range& range = m_ranges[in.rangeIndex];
+    return ConstArrayView<JSONValue>(m_arrayValues.getBuffer() + range.startIndex, range.count);
+}
+
+ConstArrayView<JSONKeyValue> JSONContainer::getObject(const JSONValue& in) const
+{
+    SLANG_ASSERT(in.type == JSONValue::Type::Array);
+    if (in.type != JSONValue::Type::Array || in.rangeIndex == 0)
+    {
+        return ConstArrayView<JSONKeyValue>((const JSONKeyValue*)nullptr, 0);
+    }
+
+    const Range& range = m_ranges[in.rangeIndex];
+    return ConstArrayView<JSONKeyValue>(m_objectValues.getBuffer() + range.startIndex, range.count);
+}
+
+ArrayView<JSONValue> JSONContainer::getArray(const JSONValue& in)
+{
+    SLANG_ASSERT(in.type == JSONValue::Type::Array);
+    if (in.type != JSONValue::Type::Array || in.rangeIndex == 0)
+    {
+        return ArrayView<JSONValue>((JSONValue*)nullptr, 0);
+    }
+    const Range& range = m_ranges[in.rangeIndex];
+    return ArrayView<JSONValue>(m_arrayValues.getBuffer() + range.startIndex, range.count);
+}
+
+ArrayView<JSONKeyValue> JSONContainer::getObject(const JSONValue& in)
+{
+    SLANG_ASSERT(in.type == JSONValue::Type::Object);
+    if (in.type != JSONValue::Type::Object || in.rangeIndex == 0)
+    {
+        return ArrayView<JSONKeyValue>((JSONKeyValue*)nullptr, 0);
+    }
+
+    const Range& range = m_ranges[in.rangeIndex];
+    return ArrayView<JSONKeyValue>(m_objectValues.getBuffer() + range.startIndex, range.count);
+}
+
+UnownedStringSlice JSONContainer::getLexeme(const JSONValue& in)
+{
+    SLANG_ASSERT(JSONValue::isLexeme(in.type));
+    if (!JSONValue::isLexeme(in.type))
+    {
+        return UnownedStringSlice();
+    }
+
+    if (!(m_currentView && m_currentView->getRange().contains(in.loc)))
+    {
+        m_currentView = m_sourceManager->findSourceView(in.loc);
+        if (!m_currentView)
+        {
+            return UnownedStringSlice();
+        }
+    }
+
+    const auto offset = m_currentView->getRange().getOffset(in.loc);
+    SourceFile* sourceFile = m_currentView->getSourceFile();
+
+    return UnownedStringSlice(sourceFile->getContent().begin() + offset, in.length);
+}
+
+UnownedStringSlice JSONContainer::getString(const JSONValue& in)
+{
+    switch (in.type)
+    {
+        case JSONValue::Type::StringValue:  return getStringFromKey(in.stringKey);
+        case JSONValue::Type::StringLexeme:
+        {
+            StringEscapeHandler* handler = StringEscapeUtil::getHandler(StringEscapeUtil::Style::JSON);
+
+            UnownedStringSlice lexeme = getLexeme(in);
+            UnownedStringSlice unquoted = StringEscapeUtil::unquote(handler, lexeme);
+
+            if (handler->isUnescapingNeeeded(unquoted))
+            {
+                m_buf.Clear();
+                handler->appendUnescaped(unquoted, m_buf);
+                return m_buf.getUnownedSlice();
+            }
+            else
+            {
+                return unquoted;
+            }
+        }
+    }
+
+    SLANG_ASSERT(!"Not a string type");
+    return UnownedStringSlice();
+}
+
+JSONKey JSONContainer::getStringKey(const JSONValue& in)
+{
+    return (in.type == JSONValue::Type::StringValue) ? in.stringKey : getKey(getString(in));
+}
+ 
+bool JSONContainer::asBool(const JSONValue& value)
+{
+    switch (value.type)
+    {
+        case JSONValue::Type::IntegerLexeme:    return asInteger(value) != 0;
+        case JSONValue::Type::FloatLexeme:      return asFloat(value) != 0.0;
+        default:                                return value.asBool();
+    }
+}
+
+int64_t JSONContainer::asInteger(const JSONValue& value)
+{
+    switch (value.type)
+    {
+        case JSONValue::Type::IntegerLexeme:
+        {
+            UnownedStringSlice slice = getLexeme(value);
+            int64_t intValue;
+            if (SLANG_SUCCEEDED(StringUtil::parseInt64(slice, intValue)) && slice.getLength() == 0)
+            {
+                return intValue;
+            }
+            SLANG_ASSERT(!"Couldn't convert int");
+            return 0;
+        }
+        case JSONValue::Type::FloatLexeme:      return int64_t(asFloat(value));
+        default:                                return value.asInteger();
+    }
+}
+
+double JSONContainer::asFloat(const JSONValue& value)
+{
+    switch (value.type)
+    {
+        case JSONValue::Type::IntegerLexeme:    return double(asInteger(value));
+        case JSONValue::Type::FloatLexeme:  
+        {
+            UnownedStringSlice slice = getLexeme(value);
+            double floatValue;
+            if (SLANG_SUCCEEDED(StringUtil::parseDouble(slice, floatValue)) && slice.getLength() == 0)
+            {
+                return floatValue;
+            }
+            SLANG_ASSERT(!"Couldn't convert double");
+            return 0.0;
+        }
+        default:                                return value.asFloat();
+    }
+}
+
+JSONValue& JSONContainer::getAt(const JSONValue& array, Index index)
+{
+    SLANG_ASSERT(array.type == JSONValue::Type::Array);
+    const Range& range = m_ranges[array.rangeIndex];
+
+    SLANG_ASSERT(index >= 0 && index < range.count);
+    return m_arrayValues[range.startIndex + index];
+}
+
+void JSONContainer::addToArray(JSONValue& array, const JSONValue& value)
+{
+    SLANG_ASSERT(array.type == JSONValue::Type::Array);
+    if (array.type == JSONValue::Type::Array)
+    {
+        // If it's empty
+        if (array.rangeIndex == 0)
+        {
+            // We can just add to the end
+            array.rangeIndex = _addRange(Range::Type::Array, m_arrayValues.getCount(), 1);
+            m_arrayValues.add(value);
+            
+        }
+        else
+        {
+            _add(m_ranges[array.rangeIndex], m_arrayValues, value);
+        }
+    }
+}
+
+Index JSONContainer::findKeyGlobalIndex(const JSONValue& obj, JSONKey key)
+{
+    SLANG_ASSERT(obj.type == JSONValue::Type::Object);
+    if (obj.type != JSONValue::Type::Object)
+    {
+        return -1;
+    }
+
+    auto buf = m_objectValues.getBuffer();
+
+    const Range& range = m_ranges[obj.rangeIndex];
+    for (Index i = range.startIndex; i < range.startIndex + range.count; ++i)
+    {
+        if (buf[i].key == key)
+        {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+Index JSONContainer::findKeyGlobalIndex(const JSONValue& obj, const UnownedStringSlice& slice)
+{
+    Index keyIndex = m_slicePool.findIndex(slice);
+    if (keyIndex < 0)
+    {
+        return -1;
+    }
+
+    return findKeyGlobalIndex(obj, JSONKey(keyIndex));
+}
+
+void JSONContainer::_removeKey(JSONValue& obj, Index globalIndex)
+{
+    Range& range = m_ranges[obj.rangeIndex];
+    const auto localIndex = globalIndex + range.startIndex;
+
+    if (localIndex < range.count - 1)
+    {
+        auto localBuf = m_objectValues.getBuffer() + range.startIndex;
+        ::memmove(localBuf + localIndex, localBuf + localIndex + 1, sizeof(*localBuf) * (range.count - (localIndex + 1)));
+    }
+
+    --range.count;
+}
+
+bool JSONContainer::removeKey(JSONValue& obj, JSONKey key)
+{
+    const Index globalIndex = findKeyGlobalIndex(obj, key);
+    if (globalIndex >= 0)
+    {
+        _removeKey(obj, globalIndex);
+        return true;
+    }
+    return false;
+}
+
+bool JSONContainer::removeKey(JSONValue& obj, const UnownedStringSlice& slice)
+{
+    const Index globalIndex = findKeyGlobalIndex(obj, slice);
+    if (globalIndex >= 0)
+    {
+        _removeKey(obj, globalIndex);
+        return true;
+    }
+    return false;
+}
+
+template <typename T>
+/* static */void JSONContainer::_add(Range& ioRange, List<T>& ioList, const T& value)
+{
+    // If we have capacity, we can add to the end
+    if (ioRange.count < ioRange.capacity)
+    {
+        ioList[ioRange.startIndex + ioRange.count++] = value;
+        return;
+    }
+
+    // If we are at the end, we can just add
+    if (ioRange.startIndex + ioRange.capacity == ioList.getCount())
+    {
+        ioList.add(value);
+        ioRange.capacity++;
+        ioRange.count++;
+        return;
+    }
+
+    // Okay we have no choice but to make new space at the end
+    // So there's no place to add. We want to move to the end with an extra space.
+
+    const Index newStartIndex = ioList.getCount();
+    ioList.growToCount(newStartIndex + ioRange.count + 1);
+
+    auto buffer = ioList.getBuffer();
+    ::memmove(buffer + newStartIndex, buffer + ioRange.startIndex, sizeof(*buffer) * ioRange.count);
+
+    buffer[newStartIndex + ioRange.count] = value;
+
+    ioRange.startIndex = newStartIndex;
+    ioRange.count++;
+    ioRange.capacity++;
+}
+
+
+void JSONContainer::setKeyValue(JSONValue& obj, JSONKey key, const JSONValue& value, SourceLoc loc)
+{
+    SLANG_ASSERT(obj.type == JSONValue::Type::Object);
+    if (obj.type != JSONValue::Type::Object)
+    {
+        return;
+    }
+
+    const JSONKeyValue keyValue{key, loc, value};
+    if (obj.rangeIndex == 0)
+    {
+        // We need a new range and add to the end
+        obj.rangeIndex = _addRange(Range::Type::Object, m_objectValues.getCount(), 1);
+        m_objectValues.add(keyValue);
+        return;
+    }
+
+    const Index globalIndex = findKeyGlobalIndex(obj, key);
+    if (globalIndex >= 0)
+    {
+        auto& dst = m_objectValues[globalIndex];
+        SLANG_ASSERT(dst.key == key);
+        dst = keyValue;
+        return;
+    }
+
+    Range& range = m_ranges[obj.rangeIndex];
+    _add(range, m_objectValues, keyValue);
+}
+
+void JSONContainer::_destroyRange(Index rangeIndex)
+{
+    auto& range = m_ranges[rangeIndex];
+
+    // If the range is at the end, shrink it
+    switch (range.type)
+    {
+        case Range::Type::Array:
+        {
+            if (range.startIndex + range.capacity == m_arrayValues.getCount())
+            {
+                m_arrayValues.setCount(range.startIndex);
+            }
+            break;
+        }
+        case Range::Type::Object:
+        {
+            if (range.startIndex + range.capacity == m_objectValues.getCount())
+            {
+                m_objectValues.setCount(range.startIndex);
+            }
+            break;
+        }
+        default: break;
+    }
+
+    range.type = Range::Type::Destroyed;
+    m_freeRangeIndices.add(rangeIndex);
+}
+
+void JSONContainer::destroy(JSONValue& value)
+{
+    if (value.needsDestroy())
+    {
+        _destroyRange(value.rangeIndex);
+    }
+    value.type = JSONValue::Type::Invalid;
+}
+
+void JSONContainer::destroyRecursively(JSONValue& inValue)
+{    
+    if (!(inValue.needsDestroy() && m_ranges[inValue.rangeIndex].isActive()))
+    {
+        inValue.type = JSONValue::Type::Invalid;
+        return;
+    }
+
+    inValue.type = JSONValue::Type::Invalid;
+
+    List<Range> activeRanges;
+
+    activeRanges.add(m_ranges[inValue.rangeIndex]);
+    _destroyRange(inValue.rangeIndex);
+
+    while (activeRanges.getCount())
+    {
+        const Range range = activeRanges.getLast();
+        activeRanges.removeLast();
+
+        auto type = range.type;
+        const Index count = range.count;
+
+        if (type == Range::Type::Array)
+        {
+            auto* buf = m_arrayValues.getBuffer() + range.startIndex;
+
+            for (Index i = 0; i < count; ++i)
+            {
+                auto& value = buf[i];
+                // If we have an active range, add to work list, and destroy 
+                if (value.needsDestroy() && m_ranges[value.rangeIndex].isActive())
+                {
+                    activeRanges.add(m_ranges[value.rangeIndex]);
+                    _destroyRange(value.rangeIndex);
+                }
+                value.type = JSONValue::Type::Invalid;
+            }
+        }
+        else 
+        {
+            SLANG_ASSERT(type == Range::Type::Object);
+
+            auto* buf = m_objectValues.getBuffer() + range.startIndex;
+
+            for (Index i = 0; i < count; ++i)
+            {
+                auto& keyValue = buf[i];
+                auto& value = keyValue.value;
+                // We want to mark that it's in the list so that if we have a badly formed tree we don't read
+                if (value.needsDestroy() && m_ranges[value.rangeIndex].isActive())
+                {
+                    activeRanges.add(m_ranges[value.rangeIndex]);
+                    _destroyRange(value.rangeIndex);
+                }
+                value.type = JSONValue::Type::Invalid;
+            }
+        }
+    }
+}
+
+bool JSONContainer::areEqual(const JSONValue* a, const JSONValue* b, Index count)
+{
+    for (Index i = 0; i < count; ++i)
+    {
+        if (!areEqual(a[i], b[i]))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+
+/* static */bool JSONContainer::_sameKeyOrder(const JSONKeyValue* a, const JSONKeyValue* b, Index count)
+{
+    for (Index i = 0; i < count; ++i)
+    {
+        if (a[i].key != b[i].key)
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool JSONContainer::_areEqualOrderedKeys(const JSONKeyValue* a, const JSONKeyValue* b, Index count)
+{
+    for (Index i = 0; i < count; ++i)
+    {
+        const auto& curA = a[i];
+        const auto& curB = b[i];
+
+        if (curA.key != curB.key ||
+            !areEqual(curA.value, curB.value))
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool JSONContainer::_areEqualValues(const JSONKeyValue* a, const JSONKeyValue* b, Index count)
+{
+    for (Index i = 0; i < count; ++i)
+    {
+        if (!areEqual(a[i].value, b[i].value))
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool JSONContainer::areEqual(const JSONKeyValue* a, const JSONKeyValue* b, Index count)
+{
+    if (count == 0)
+    {
+        return true;
+    }
+
+    if (count == 1)
+    {
+        return _areEqualOrderedKeys(a, b, count);
+    }
+    else if (_sameKeyOrder(a, b, count))
+    {
+        return _areEqualValues(a, b, count);
+    }
+    else
+    {
+            // We need to compare with keys in the same order
+        List<JSONKeyValue> sortedAs;
+        sortedAs.addRange(a, count);
+
+        List<JSONKeyValue> sortedBs;
+        sortedBs.addRange(b, count);
+
+        sortedAs.sort([](const JSONKeyValue&a, const JSONKeyValue& b) -> bool { return a.key < b.key; });
+        sortedBs.sort([](const JSONKeyValue&a, const JSONKeyValue& b) -> bool { return a.key < b.key; });
+
+        return _areEqualOrderedKeys(sortedAs.getBuffer(), sortedBs.getBuffer(), count);
+    }
+}
+
+bool JSONContainer::areEqual(const JSONValue& a, const JSONValue& b)
+{
+    if (&a == &b)
+    {
+        return true;
+    }
+
+    if (a.type == b.type)
+    {
+        switch (a.type)
+        {
+            default:
+            // Invalid are never equal
+            case JSONValue::Type::Invalid:      return false;
+            case JSONValue::Type::True:         
+            case JSONValue::Type::False:        
+            case JSONValue::Type::Null:
+            {
+                return true;
+            }
+            case JSONValue::Type::IntegerLexeme:return asInteger(a) == asInteger(b); 
+            case JSONValue::Type::FloatLexeme:  return asFloat(a) == asFloat(b);
+            case JSONValue::Type::StringLexeme:
+            {
+                // If the lexemes are equal they are equal
+                UnownedStringSlice lexemeA = getLexeme(a);
+                UnownedStringSlice lexemeB = getLexeme(b);
+                // Else we want to decode the string to be sure if they are equal.
+                return lexemeA == lexemeB || getStringKey(a) == getStringKey(b);
+            }
+            case JSONValue::Type::IntegerValue: return a.intValue == b.intValue;
+            case JSONValue::Type::FloatValue:   return a.floatValue == b.floatValue;
+            case JSONValue::Type::StringValue:  return a.stringKey == b.stringKey;
+
+            case JSONValue::Type::Array:
+            {
+                if (a.rangeIndex == b.rangeIndex)
+                {
+                    return true;
+                }
+                auto arrayA = getArray(a);
+                auto arrayB = getArray(b);
+
+                const Index count = arrayA.getCount();
+                return (count == arrayB.getCount()) && areEqual(arrayA.getBuffer(), arrayB.getBuffer(), count);
+            }
+            case JSONValue::Type::Object:
+            {
+                if (a.rangeIndex == b.rangeIndex)
+                {
+                    return true;
+                }
+                const auto aValues = getObject(a);
+                const auto bValues = getObject(b);
+
+                const Index count = aValues.getCount();
+                return (count == bValues.getCount()) && areEqual(aValues.getBuffer(), bValues.getBuffer(), count);
+            }
+        }
+    }
+
+    // If they are the same kind, and float/int/string we can convert to compare
+    const JSONValue::Kind kind = a.getKind();
+    if (kind == b.getKind())
+    {
+        switch (kind)
+        {
+            case JSONValue::Kind::String:   return getStringKey(a) == getStringKey(b); 
+            case JSONValue::Kind::Integer:  return asInteger(a) == asInteger(b);
+            case JSONValue::Kind::Float:    return asFloat(a) == asFloat(b);
+            default: break;
+        }
+    }
+
+    return false;
+}
+
+} // namespace Slang
diff --git a/source/compiler-core/slang-json-value.h b/source/compiler-core/slang-json-value.h
new file mode 100644
index 000000000..48cde5750
--- /dev/null
+++ b/source/compiler-core/slang-json-value.h
@@ -0,0 +1,243 @@
+// slang-json-value.h
+#ifndef SLANG_JSON_VALUE_H
+#define SLANG_JSON_VALUE_H
+
+#include "../core/slang-basic.h"
+
+#include "slang-source-loc.h"
+#include "slang-diagnostic-sink.h"
+
+namespace Slang {
+
+typedef uint32_t JSONKey;
+
+struct JSONValue
+{
+    enum class Kind
+    {
+        Invalid,
+
+        Null,
+
+        Bool,
+        String,
+        Integer,
+        Float,
+
+        Array,
+        Object,
+
+        CountOf, 
+    };
+
+    enum class Type
+    {
+        Invalid,
+
+        True,
+        False,
+        Null,
+
+        StringLexeme,
+        IntegerLexeme,
+        FloatLexeme,
+
+        IntegerValue,
+        FloatValue,
+        StringValue,
+
+        Array,
+        Object,
+
+        CountOf,
+    };
+
+    static bool isLexeme(Type type) { return Index(type) >= Index(Type::StringLexeme) && Index(type) <= Index(Type::FloatLexeme); }
+
+    static JSONValue makeInt(int64_t inValue, SourceLoc loc = SourceLoc()) { JSONValue value; value.type = Type::IntegerValue; value.loc = loc; value.intValue = inValue; return value; }
+    static JSONValue makeFloat(double inValue, SourceLoc loc = SourceLoc()) { JSONValue value; value.type = Type::FloatValue; value.loc = loc; value.floatValue = inValue; return value; }
+    static JSONValue makeNull(SourceLoc loc = SourceLoc()) { JSONValue value; value.type = Type::Null; value.loc = loc; return value; }
+    static JSONValue makeBool(bool inValue, SourceLoc loc = SourceLoc()) { JSONValue value; value.type = (inValue ? Type::True : Type::False); value.loc = loc; return value; }
+
+    static JSONValue makeLexeme(Type type, SourceLoc loc,  Index length) { SLANG_ASSERT(isLexeme(type)); JSONValue value; value.type = type; value.loc = loc; value.length = length; return value; }
+
+    static JSONValue makeEmptyArray(SourceLoc loc = SourceLoc()) { JSONValue value; value.type = Type::Array; value.loc = loc; value.rangeIndex = 0; return value; }
+    static JSONValue makeEmptyObject(SourceLoc loc = SourceLoc()) { JSONValue value; value.type = Type::Object; value.loc = loc; value.rangeIndex = 0; return value; }
+
+    // The following functions only work if the value is stored directly NOT as a lexeme. Use the methods on the container
+    // to access values if it is potentially stored as a lexeme
+
+        /// As a boolean value 
+    bool asBool() const;
+        /// As an integer value
+    int64_t asInteger() const;
+        /// As a float value
+    double asFloat() const;
+
+        /// True if this is a object like (array or object)
+    bool isObjectLike() const { return Index(type) >= Index(Type::Array); }
+
+        /// True if this appears to be a valid value
+    bool isValid() const { return type != JSONValue::Type::Invalid; }
+
+        /// True if needs destroy
+    bool needsDestroy() const { return isObjectLike() && rangeIndex != 0; }
+
+        /// Get the kind
+    SLANG_FORCE_INLINE Kind getKind() const { return getKindForType(type); }
+
+        /// Given a type return the associated kind
+    static Kind getKindForType(Type type) { return g_typeToKind[Index(type)]; }
+
+    Type type;                  ///< The type of value
+    SourceLoc loc;              ///< The (optional) location in source of this value.
+
+    union 
+    {
+        Index rangeIndex;           ///< Used for Array/Object
+        Index length;               ///< Length in bytes if it is a 'Lexeme'
+        double floatValue;          ///< Float value
+        int64_t intValue;           ///< Integer value
+        JSONKey stringKey;          ///< The pool key if it's a string
+    };
+
+    static const Kind g_typeToKind[Index(Type::CountOf)];
+};
+
+struct JSONKeyValue
+{
+        /// True if it's valid
+    bool isValid() const { return value.type != JSONValue::Type::Invalid; }
+
+    JSONKey key;
+    SourceLoc keyLoc;
+    JSONValue value;
+
+    static JSONKeyValue g_invalid;
+};
+
+class JSONContainer : public RefObject
+{
+public:
+
+        /// Make a new array
+    JSONValue createArray(const JSONValue* values, Index valuesCount, SourceLoc loc = SourceLoc());
+        /// Make a new object
+    JSONValue createObject(const JSONKeyValue* keyValues, Index keyValueCount, SourceLoc loc = SourceLoc());
+        /// Make a string
+    JSONValue createString(const UnownedStringSlice& slice, SourceLoc loc = SourceLoc()); 
+
+    ConstArrayView<JSONValue> getArray(const JSONValue& in) const;
+    ConstArrayView<JSONKeyValue> getObject(const JSONValue& in) const;
+
+    ArrayView<JSONValue> getArray(const JSONValue& in);
+    ArrayView<JSONKeyValue> getObject(const JSONValue& in);
+
+        /// Add value to array.
+    void addToArray(JSONValue& array, const JSONValue& value);
+
+        /// Get the value at the index in the array
+    JSONValue& getAt(const JSONValue& array, Index index);
+
+        /// Returns the index 
+    Index findKeyGlobalIndex(const JSONValue& obj, JSONKey key);
+    Index findKeyGlobalIndex(const JSONValue& obj, const UnownedStringSlice& slice);
+
+        /// Set a key value for the obj
+    void setKeyValue(JSONValue& obj, JSONKey key, const JSONValue& value, SourceLoc loc = SourceLoc());
+
+        /// Returns true if found
+    bool removeKey(JSONValue& obj, JSONKey key);
+    bool removeKey(JSONValue& obj, const UnownedStringSlice& slice);
+
+        /// As a boolean value
+    bool asBool(const JSONValue& value);
+        /// As an integer value
+    int64_t asInteger(const JSONValue& value);
+        /// As a float value
+    double asFloat(const JSONValue& value);
+
+        /// Returns string as a key
+    JSONKey getStringKey(const JSONValue& in);
+
+        /// Get as a string. 
+    UnownedStringSlice getString(const JSONValue& in);
+
+        /// Gets the lexeme
+    UnownedStringSlice getLexeme(const JSONValue& in);
+
+        /// Get a key for a name
+    JSONKey getKey(const UnownedStringSlice& slice);
+        /// Get the string from the key
+    UnownedStringSlice getStringFromKey(JSONKey key) const { return m_slicePool.getSlice(StringSlicePool::Handle(key)); }
+
+        /// True if they are the same value
+        /// If object like type comparison is performed recursively.
+        /// NOTE! That Float and Integer values do not compare & source locations are ignored.
+    bool areEqual(const JSONValue& a, const JSONValue& b);
+    bool areEqual(const JSONValue* a, const JSONValue* b, Index count);
+    bool areEqual(const JSONKeyValue* a, const JSONKeyValue* b, Index count);
+
+        /// Destroy value
+    void destroy(JSONValue& value);
+        /// Destroy recursively from value
+    void destroyRecursively(JSONValue& value);
+
+        //
+    JSONContainer(SourceManager* sourceManger);
+
+        /// Returns true if all the keys are unique
+    static bool areKeysUnique(const JSONKeyValue* keyValues, Index keyValueCount);
+
+protected:
+    struct Range
+    {
+        // We want to record the underlying range, because we don't track JSONValue, and so we need to know what the range
+        // applies to if we want to reorder, flatten etc.
+        enum class Type
+        {
+            None,
+            Destroyed,
+            Object,
+            Array,
+        };
+
+            /// Is active if it consuming some part of a value list (even if zero count)
+        SLANG_FORCE_INLINE bool isActive() const { return Index(type) >= Index(Type::Object); }
+
+        Type type;
+        Index startIndex;
+        Index count;
+        Index capacity;
+    };
+
+    template <typename T>
+    static void _add(Range& range, List<T>& list, const T& value);
+
+    Index _addRange(Range::Type type, Index startIndex, Index count);
+    void _removeKey(JSONValue& obj, Index globalIndex);
+        /// Note does not destroy values in range.
+    void _destroyRange(Index rangeIndex);
+
+    static bool _sameKeyOrder(const JSONKeyValue* a, const JSONKeyValue* b, Index count);
+        /// True if the values are equal
+    bool _areEqualValues(const JSONKeyValue* a, const JSONKeyValue* b, Index count);
+        /// True if the key and value are equal
+    bool _areEqualOrderedKeys(const JSONKeyValue* a, const JSONKeyValue* b, Index count);
+
+    StringBuilder m_buf;                        ///< A temporary buffer used to hold unescaped strings
+
+    SourceView* m_currentView = nullptr;
+    SourceManager* m_sourceManager;
+
+    StringSlicePool m_slicePool;
+    List<Range> m_ranges;
+    List<Index> m_freeRangeIndices;
+    List<JSONValue> m_arrayValues;
+    List<JSONKeyValue> m_objectValues;
+
+};
+
+} // namespace Slang
+
+#endif