2 files changed, 207 insertions, 0 deletions
diff --git a/source/compiler-core/slang-pretty-writer.cpp b/source/compiler-core/slang-pretty-writer.cpp
new file mode 100644
index 000000000..682b02c1e
--- /dev/null
+++ b/source/compiler-core/slang-pretty-writer.cpp
@@ -0,0 +1,85 @@
+#include "slang-pretty-writer.h"
+
+#include "../core/slang-string-escape-util.h"
+
+namespace Slang
+{
+
+void PrettyWriter::writeRaw(char const* begin, char const* end)
+{
+    SLANG_ASSERT(end >= begin);
+    writeRaw(UnownedStringSlice(begin, end));
+}
+
+void PrettyWriter::adjust()
+{
+    // Only indent if at start of a line
+    if (m_startOfLine)
+    {
+        // Output current indentation
+        m_builder.appendRepeatedChar(' ', m_indent * 4);
+        m_startOfLine = false;
+    }
+}
+
+void PrettyWriter::dedent()
+{
+    SLANG_ASSERT(m_indent > 0);
+    m_indent--;
+}
+
+void PrettyWriter::write(const UnownedStringSlice& slice)
+{
+    const auto end = slice.end();
+    auto start = slice.begin();
+
+    while (start < end)
+    {
+        const char* cur = start;
+
+        // Search for \n if there is one
+        while (cur < end && *cur != '\n')
+            cur++;
+
+        // If there were some chars, adjust and write
+        if (cur > start)
+        {
+            adjust();
+            writeRaw(UnownedStringSlice(start, cur));
+        }
+
+        if (cur < end && *cur == '\n')
+        {
+            writeRawChar('\n');
+            // Skip the CR
+            cur++;
+            // Mark we are at the start of a line
+            m_startOfLine = true;
+        }
+
+        start = cur;
+    }
+}
+
+void PrettyWriter::writeEscapedString(const UnownedStringSlice& slice)
+{
+    adjust();
+    auto handler = StringEscapeUtil::getHandler(StringEscapeUtil::Style::Cpp);
+    StringEscapeUtil::appendQuoted(handler, slice, m_builder);
+}
+
+void PrettyWriter::maybeComma()
+{
+    if (auto state = m_commaState)
+    {
+        if (!state->needComma)
+        {
+            state->needComma = true;
+            return;
+        }
+    }
+
+    write(toSlice(",\n"));
+}
+
+} // namespace Slang
diff --git a/source/compiler-core/slang-pretty-writer.h b/source/compiler-core/slang-pretty-writer.h
new file mode 100644
index 000000000..6817047a2
--- /dev/null
+++ b/source/compiler-core/slang-pretty-writer.h
@@ -0,0 +1,122 @@
+#ifndef SLANG_CORE_PRETTY_WRITER_H
+#define SLANG_CORE_PRETTY_WRITER_H
+
+
+#include "../core/slang-char-util.h"
+#include "../core/slang-string-util.h"
+#include "../core/slang-string.h"
+
+namespace Slang
+{
+
+struct PrettyWriter
+{
+    typedef PrettyWriter ThisType;
+
+    friend struct CommaTrackerRAII;
+
+    struct CommaState
+    {
+        bool needComma = false;
+    };
+
+    void writeRaw(const UnownedStringSlice& slice) { m_builder.append(slice); }
+    void writeRaw(char const* begin, char const* end);
+    void writeRaw(char const* begin) { writeRaw(UnownedStringSlice(begin)); }
+
+    void writeRawChar(int c) { m_builder.appendChar(char(c)); }
+
+    void writeHexChar(int c) { writeRawChar(CharUtil::getHexChar(Index(c))); }
+
+    /// Adjusts indentation if at start of a line
+    void adjust();
+
+    /// Increase indentation
+    void indent() { m_indent++; }
+    /// Decreate indentation
+    void dedent();
+
+    /// Write taking into account any CR that might be in a slice
+    void write(const UnownedStringSlice& slice);
+    void write(char const* text) { write(UnownedStringSlice(text)); }
+    void write(char const* text, size_t length) { write(UnownedStringSlice(text, length)); }
+
+    /// Write the slice as an escaped string
+    void writeEscapedString(const UnownedStringSlice& slice);
+
+    /// Call before items in a comma-separated JSON list to emit the comma if/when needed
+    void maybeComma();
+
+    /// Get the builder the result is being constructed in
+    StringBuilder& getBuilder() { return m_builder; }
+
+    ThisType& operator<<(const UnownedStringSlice& slice)
+    {
+        write(slice);
+        return *this;
+    }
+    ThisType& operator<<(const char* text)
+    {
+        write(text);
+        return *this;
+    }
+    ThisType& operator<<(uint64_t val)
+    {
+        adjust();
+        m_builder << val;
+        return *this;
+    }
+    ThisType& operator<<(int64_t val)
+    {
+        adjust();
+        m_builder << val;
+        return *this;
+    }
+    ThisType& operator<<(int32_t val)
+    {
+        adjust();
+        m_builder << val;
+        return *this;
+    }
+    ThisType& operator<<(uint32_t val)
+    {
+        adjust();
+        m_builder << val;
+        return *this;
+    }
+    ThisType& operator<<(float val)
+    {
+        adjust();
+        // We want to use a specific format, so we use the StringUtil to specify format, and not
+        // just use <<
+        StringUtil::appendFormat(m_builder, "%f", val);
+        return *this;
+    }
+
+    bool m_startOfLine = true;
+    int m_indent = 0;
+    CommaState* m_commaState = nullptr;
+    StringBuilder m_builder;
+};
+
+/// Type for tracking whether a comma is needed in a comma-separated JSON list
+struct CommaTrackerRAII
+{
+    CommaTrackerRAII(PrettyWriter& writer)
+        : m_writer(&writer), m_previousState(writer.m_commaState)
+    {
+        writer.m_commaState = &m_state;
+    }
+
+    ~CommaTrackerRAII() { m_writer->m_commaState = m_previousState; }
+
+private:
+    PrettyWriter::CommaState m_state;
+    PrettyWriter* m_writer;
+    PrettyWriter::CommaState* m_previousState;
+};
+
+} // namespace Slang
+
+
+#endif