Util: Switch from format() to struct Formatter

src/util/format/builder.cpp

@@ -28,7 +28,7 @@ void Builder::putLiteral(std::string_view literal)
 
 void Builder::putF32(float number, size_t precision) const
 {
-	precision = (precision > std::numeric_limits<float>::digits10) ? m_precision : precision;
+	precision = (precision > std::numeric_limits<float>::digits10) ? 6 : precision;
 
 	std::stringstream stream;
 	stream
@@ -41,7 +41,7 @@ void Builder::putF32(float number, size_t precision) const
 
 void Builder::putF64(double number, size_t precision) const
 {
-	precision = (precision > std::numeric_limits<double>::digits10) ? m_precision : precision;
+	precision = (precision > std::numeric_limits<double>::digits10) ? 6 : precision;
 
 	std::stringstream stream;
 	stream
@@ -52,9 +52,4 @@ void Builder::putF64(double number, size_t precision) const
 	m_builder << string;
 }
 
-void Builder::resetSpecifiers()
-{
-	setPrecision();
-}
-
 } // namespace Util::Format

src/util/format/builder.h

@@ -16,8 +16,7 @@ namespace Util::Format {
 class Builder {
 public:
 	explicit Builder(std::stringstream& builder)
-		: m_precision(6)
-		, m_builder(builder)
+		: m_builder(builder)
 	{
 	}
 
@@ -27,20 +26,16 @@ public:
 	void putU32(uint32_t number) const { m_builder << number; } // unsigned int
 	void putI64(int64_t number) const { m_builder << number; }  // long int
 	void putU64(size_t number) const { m_builder << number; }   // long unsigned int
-	void putF32(float number, size_t precision = -1) const;
-	void putF64(double number, size_t precision = -1) const;
+	void putF32(float number, size_t precision = 6) const;
+	void putF64(double number, size_t precision = 6) const;
 	void putCharacter(char character) const { m_builder.write(&character, 1); }
 	void putString(const std::string_view string) const { m_builder.write(string.data(), string.length()); }
 	void putPointer(const void* pointer) const { m_builder << pointer; }
 
-	void resetSpecifiers();
-	void setPrecision(size_t precision = 6) { m_precision = precision; };
-
 	const std::stringstream& builder() const { return m_builder; }
 	std::stringstream& builder() { return m_builder; }
 
 private:
-	size_t m_precision { 6 };
 	std::stringstream& m_builder;
 };
 

src/util/format/format.cpp

@@ -11,27 +11,36 @@
 #include "util/format/builder.h"
 #include "util/format/format.h"
 #include "util/format/parser.h"
+#include "util/meta/assert.h"
 
 namespace Util::Format {
 
 void variadicFormatImpl(Builder& builder, Parser& parser, TypeErasedParameters& parameters)
 {
+	// Consume everything until '{' or EOF
 	const auto literal = parser.consumeLiteral();
 	builder.putLiteral(literal);
 
-	if (!parameters.isEOF()) {
-		std::string_view specifier;
-		if (parser.consumeSpecifier(specifier)) {
-			parser.applySpecifier(builder, specifier);
-		}
+	// Reached end of format string
+	if (parser.isEOF()) {
+		return;
+	}
 
-		auto& parameter = parameters.parameter(parameters.tell());
-		parameter.format(builder, parameter.value);
-		parameters.ignore();
+	// Consume index + ':'
+	auto indexMaybe = parser.consumeIndex();
 
-		builder.resetSpecifiers();
-	}
+	// Get parameter at index, or next
+	size_t index = indexMaybe.has_value() ? indexMaybe.value() : parameters.tell();
+	VERIFY(index < parameters.size(), "argument not found at index '%zu':'%zu'", index, parameters.size());
+	auto& parameter = parameters.parameter(index);
+
+	// Format the parameter
+	parameter.format(builder, parser, parameter.value);
+
+	// Go to next parameter
+	parameters.ignore();
 
+	// Recurse
 	if (!parser.isEOF()) {
 		variadicFormatImpl(builder, parser, parameters);
 	}

src/util/format/format.h

@@ -28,7 +28,8 @@ struct Parameter {
 template<typename T>
 void formatParameterValue(Builder& builder, const void* value)
 {
-	_format(builder, *static_cast<const T*>(value));
+	Formatter<T> formatter;
+	formatter.format(builder, *static_cast<const T*>(value));
 }
 
 // Type erasure improves both compile time and binary size significantly

src/util/format/formatter.cpp

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2022 Riyyi
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <cstddef> // size_t
+#include <cstdint> // int32_t, uint32_t, int64_t,
+#include <cstring> // strlen
+#include <string>
+#include <string_view>
+
+#include "util/format/builder.h"
+#include "util/format/formatter.h"
+#include "util/format/parser.h"
+
+namespace Util::Format {
+
+// Integral
+
+template<>
+void Formatter<int32_t>::format(Builder& builder, int32_t value) const
+{
+	builder.putI32(value);
+}
+
+template<>
+void Formatter<uint32_t>::format(Builder& builder, uint32_t value) const
+{
+	builder.putU32(value);
+}
+
+template<>
+void Formatter<int64_t>::format(Builder& builder, int64_t value) const
+{
+	builder.putI64(value);
+}
+
+template<>
+void Formatter<size_t>::format(Builder& builder, size_t value) const
+{
+	builder.putU64(value);
+}
+
+// Floating point
+
+template<>
+void Formatter<float>::format(Builder& builder, float value) const
+{
+	builder.putF32(value);
+}
+
+template<>
+void Formatter<double>::format(Builder& builder, double value) const
+{
+	builder.putF64(value);
+}
+
+// Char
+
+template<>
+void Formatter<char>::format(Builder& builder, char value) const
+{
+	builder.putCharacter(value);
+}
+
+template<>
+void Formatter<bool>::format(Builder& builder, bool value) const
+{
+	builder.putString(value ? "true" : "false");
+}
+
+// String
+
+void Formatter<const char*>::format(Builder& builder, const char* value) const
+{
+	builder.putString(value != nullptr ? std::string_view { value, strlen(value) } : "(nil)");
+}
+
+template<>
+void Formatter<std::string_view>::format(Builder& builder, std::string_view value) const
+{
+	builder.putString(value);
+}
+
+// Pointer
+
+void Formatter<std::nullptr_t>::format(Builder& builder, std::nullptr_t) const
+{
+	Formatter<const void*>::format(builder, 0);
+}
+
+// Containers
+
+} // namespace Util::Format

src/util/format/formatter.h

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2022 Riyyi
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <cstddef> // size_t
+#include <cstdint> // int32_t, uint8_t, uint32_t, int64_t,
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include "util/format/builder.h"
+#include "util/format/parser.h"
+
+namespace Util::Format {
+
+
+template<typename T>
+struct Formatter {
+
+	void format(Builder& builder, T value) const { (void)builder, (void)value; }
+};
+
+// Integral
+
+template<>
+void Formatter<int32_t>::format(Builder& builder, int32_t value) const;
+
+template<>
+void Formatter<uint32_t>::format(Builder& builder, uint32_t value) const;
+
+template<>
+void Formatter<int64_t>::format(Builder& builder, int64_t value) const;
+
+template<>
+void Formatter<size_t>::format(Builder& builder, size_t value) const; // uint64_t
+
+// Floating point
+
+template<>
+void Formatter<float>::format(Builder& builder, float value) const;
+
+template<>
+void Formatter<double>::format(Builder& builder, double value) const;
+
+// Char
+
+template<>
+void Formatter<char>::format(Builder& builder, char value) const;
+
+template<>
+void Formatter<bool>::format(Builder& builder, bool value) const;
+
+// String
+
+template<>
+void Formatter<std::string_view>::format(Builder& builder, std::string_view value) const;
+
+template<>
+struct Formatter<std::string> : Formatter<std::string_view> {
+};
+
+template<>
+struct Formatter<const char*> : Formatter<std::string_view> {
+	void format(Builder& builder, const char* value) const;
+};
+
+template<>
+struct Formatter<char*> : Formatter<const char*> {
+};
+
+template<size_t N>
+struct Formatter<char[N]> : Formatter<const char*> {
+};
+
+// Pointer
+
+template<typename T>
+struct Formatter<T*> {
+	void format(Builder& builder, T* value) const
+	{
+		value == nullptr
+			? builder.putString("0x0")
+			: builder.putPointer(static_cast<const void*>(value));
+	}
+};
+
+template<>
+struct Formatter<std::nullptr_t> : Formatter<const void*> {
+	void format(Builder& builder, std::nullptr_t) const;
+};
+
+// Container
+
+template<typename T>
+struct Formatter<std::vector<T>> : Formatter<T> {
+	void format(Builder& builder, const std::vector<T>& value) const
+	{
+		builder.putString("{\n");
+		for (auto it = value.cbegin(); it != value.cend(); ++it) {
+			builder.putString("    ");
+			Formatter<T>::format(builder, *it);
+
+			// Add comma, except after the last element
+			if (it != std::prev(value.end(), 1)) {
+				builder.putCharacter(',');
+			}
+			builder.putCharacter('\n');
+		}
+		builder.putCharacter('}');
+	}
+};
+
+} // namespace Util::Format

src/util/format/parser.cpp

@@ -6,6 +6,7 @@
 
 #include <algorithm> // replace
 #include <cstddef>   // size_t
+#include <limits>    // numeric_limits
 #include <string>
 #include <string_view>
 
@@ -53,7 +54,9 @@ void Parser::checkFormatParameterConsistency()
 		if (peek0 == '{') {
 			braceOpen++;
 
-			VERIFY(peek1 == '}' || peek1 == ':', "invalid parameter reference");
+			if (peek1 >= '0' && peek1 <= '9') {
+				m_mode = ArgumentIndexingMode::Manual;
+			}
 		}
 		if (peek0 == '}') {
 			braceClose++;
@@ -63,13 +66,13 @@ void Parser::checkFormatParameterConsistency()
 	}
 	m_index = 0;
 
-	VERIFY(!(braceOpen < braceClose), "extra open braces in format string");
+	// VERIFY(!(braceOpen < braceClose), "extra open braces in format string");
 
-	VERIFY(!(braceOpen > braceClose), "extra closing braces in format string");
+	// VERIFY(!(braceOpen > braceClose), "extra closing braces in format string");
 
-	VERIFY(!(braceOpen < m_parameterCount), "format string does not reference all passed parameters");
+	// VERIFY(!(braceOpen < m_parameterCount), "format string does not reference all passed parameters");
 
-	VERIFY(!(braceOpen > m_parameterCount), "format string references nonexistent parameter");
+	// VERIFY(!(braceOpen > m_parameterCount), "format string references nonexistent parameter");
 }
 
 std::string_view Parser::consumeLiteral()
@@ -101,44 +104,63 @@ std::string_view Parser::consumeLiteral()
 	return m_input.substr(begin);
 }
 
-bool Parser::consumeSpecifier(std::string_view& specifier)
+std::optional<size_t> Parser::consumeIndex()
 {
 	if (!consumeSpecific('{')) {
-		return false;
+		VERIFY_NOT_REACHED();
+		return {};
 	}
 
-	if (!consumeSpecific(':')) {
-		VERIFY(consumeSpecific('}'), "invalid parameter reference");
-		specifier = "";
+	switch (m_mode) {
+	case ArgumentIndexingMode::Automatic: {
+		VERIFY(consumeSpecific('}') || consumeSpecific(':'), "expecting '}' or ':', not '%c'", peek());
+		return {};
 	}
-	else {
+	case ArgumentIndexingMode::Manual: {
 		const auto begin = tell();
 
-		// Go until AFTER the closing brace
-		while (peek(-1) != '}') {
-			consume();
+		while (!isEOF()) {
+			char peek0 = peek();
+			if (peek0 == '}' || peek0 == ':') {
+				break;
+			}
+
+			VERIFY(peek0 >= '0' && peek0 <= '9', "expecting number, not '%c'", peek0);
+
+			ignore();
+		}
+
+		size_t result = stringToNumber(m_input.substr(begin, tell() - begin));
+
+		if (peek() == ':') {
+			ignore();
 		}
 
-		specifier = m_input.substr(begin, tell() - begin - 1);
+		return result;
 	}
+	};
 
-	return true;
+	VERIFY_NOT_REACHED();
 }
 
-void Parser::applySpecifier(Builder& builder, std::string_view specifier)
+size_t Parser::stringToNumber(std::string_view value)
 {
-	if (specifier[0] == '.') {
-		size_t value = 0;
+	size_t result = 0;
+
+	for (size_t i = 1; i < value.length(); ++i) {
+		if (value[i] < '0' || value[i] > '9') {
+			VERIFY_NOT_REACHED();
+		}
+		result *= 10;
+		result += value[i] - '0'; // Subtract ASCII 48 to get the number
+	}
+
+	return result;
+}
 
-		for (size_t i = 1; i < specifier.length(); ++i) {
-			if (specifier[i] < '0' || specifier[i] > '9') {
-				return;
 			}
-			value *= 10;
-			value += specifier[i] - '0'; // Subtract ASCII 48 to get the number
 		}
 
-		builder.setPrecision(value);
 	}
 }
 

src/util/format/parser.h

@@ -6,7 +6,8 @@
 
 #pragma once
 
-#include <cstddef>   // size_t
+#include <cstddef> // size_t
+#include <optional>
 #include <string_view>
 
 #include "util/genericlexer.h"
@@ -17,17 +18,24 @@ class Builder;
 
 class Parser final : public GenericLexer {
 public:
+	enum class ArgumentIndexingMode {
+		Automatic, // {} ,{}
+		Manual,    // {0},{1}
+	};
+
 	Parser(std::string_view format, size_t parameterCount);
 	virtual ~Parser();
 
 	void checkFormatParameterConsistency();
 
 	std::string_view consumeLiteral();
-	bool consumeSpecifier(std::string_view& specifier);
+	std::optional<size_t> consumeIndex();
+
+	size_t stringToNumber(std::string_view value);
 
-	void applySpecifier(Builder& builder, std::string_view specifier);
 
 private:
+	ArgumentIndexingMode m_mode { ArgumentIndexingMode::Automatic };
 	size_t m_parameterCount { 0 };
 };