Simplify txtdata parsing with a helper class

Packaging/resources/assets/txtdata/items/item_prefixes.tsv

@@ -1,4 +1,4 @@
-name	power.type	power.param1	power.param2	minLevel	itemTypes	alignment	doubleChance	useful	minVal	maxVal	multVal
+name	power.type	power.value1	power.value2	minLevel	itemTypes	alignment	doubleChance	useful	minVal	maxVal	multVal
 Tin	TOHIT_CURSE	6	10	3	Weapon,Bow,Misc	Any	true	false	0	0	-3
 Brass	TOHIT_CURSE	1	5	1	Weapon,Bow,Misc	Any	true	false	0	0	-2
 Bronze	TOHIT	1	5	1	Weapon,Bow,Misc	Any	true	true	100	500	2

Packaging/resources/assets/txtdata/items/item_suffixes.tsv

@@ -1,4 +1,4 @@
-name	power.type	power.param1	power.param2	minLevel	itemTypes	alignment	doubleChance	useful	minVal	maxVal	multVal
+name	power.type	power.value1	power.value2	minLevel	itemTypes	alignment	doubleChance	useful	minVal	maxVal	multVal
 quality	DAMMOD	1	2	2	Weapon,Staff,Bow	Any	false	true	100	200	2
 maiming	DAMMOD	3	5	7	Weapon,Staff,Bow	Any	false	true	1300	1500	3
 slaying	DAMMOD	6	8	15	Weapon	Any	false	true	2600	3000	5

Packaging/resources/assets/txtdata/items/unique_itemdat.tsv

@@ -1,4 +1,4 @@
-name	uniqueBaseItem	minLevel	value	powers[0].type	powers[0].param1	powers[0].param2	powers[1].type	powers[1].param1	powers[1].param2	powers[2].type	powers[2].param1	powers[2].param2	powers[3].type	powers[3].param1	powers[3].param2	powers[4].type	powers[4].param1	powers[4].param2	powers[5].type	powers[5].param1	powers[5].param2
+name	uniqueBaseItem	minLevel	value	power0.type	power0.value1	power0.value2	power1.type	power1.value1	power1.value2	power2.type	power2.value1	power2.value2	power3.type	power3.value1	power3.value2	power4.type	power4.value1	power4.value2	power5.type	power5.value1	power5.value2
 The Butcher's Cleaver	CLEAVER	1	3650	STR	10	10	SETDAM	4	24	SETDUR	10	10									
 The Undead Crown	SKCROWN	1	16650	RNDSTEALLIFE			SETAC	8	8	INVCURS	77										
 Empyrean Band	INFRARING	1	8000	ATTRIBS	2	2	LIGHT	2	2	FASTRECOVER	1	1	ABSHALFTRAP								

Source/.clang-tidy

@@ -53,7 +53,8 @@ Checks: >
   -modernize-avoid-c-arrays,
   -modernize-use-trailing-return-type,
   -modernize-concat-nested-namespaces,
-  -modernize-avoid-bind
+  -modernize-avoid-bind,
+  -modernize-use-constraints
 
 HeaderFilterRegex: "^(Source|test)\\.h$"
 

Source/CMakeLists.txt

@@ -70,6 +70,7 @@ set(libdevilutionx_SRCS
 
   data/file.cpp
   data/parser.cpp
+  data/record_reader.cpp
 
   DiabloUI/button.cpp
   DiabloUI/credits.cpp

Source/data/iterators.hpp

@@ -146,7 +146,7 @@ class DataFileField {
 	}
 
 	template <typename T, typename ParseFn>
-	[[nodiscard]] tl::expected<void, Error> parseEnumList(T &destination, ParseFn &&parseFn)
+	[[nodiscard]] tl::expected<void, std::string> parseEnumList(T &destination, ParseFn &&parseFn)
 	{
 		destination = {};
 		const std::string_view str = value();
@@ -155,7 +155,7 @@ class DataFileField {
 		for (const std::string_view part : SplitByChar(str, ',')) {
 			auto result = parseFn(part);
 			if (!result.has_value())
-				return tl::make_unexpected(Error::InvalidValue);
+				return tl::make_unexpected(std::move(result).error());
 			destination |= result.value();
 		}
 		return {};

Source/data/record_reader.cpp

@@ -0,0 +1,17 @@
+#include "data/record_reader.hpp"
+
+namespace devilution {
+
+void RecordReader::advance()
+{
+	if (needsIncrement_) {
+		++it_;
+	} else {
+		needsIncrement_ = true;
+	}
+	if (it_ == end_) {
+		DataFile::reportFatalError(DataFile::Error::NotEnoughColumns, filename_);
+	}
+}
+
+} // namespace devilution

Source/data/record_reader.hpp

@@ -0,0 +1,123 @@
+#pragma once
+
+#include <string_view>
+#include <type_traits>
+
+#include <expected.hpp>
+#include <function_ref.hpp>
+
+#include "data/file.hpp"
+#include "data/iterators.hpp"
+
+namespace devilution {
+
+/**
+ * @brief A record reader that treats every error as fatal.
+ */
+class RecordReader {
+public:
+	RecordReader(DataFileRecord &record, std::string_view filename)
+	    : it_(record.begin())
+	    , end_(record.end())
+	    , filename_(filename)
+	{
+	}
+
+	template <typename T>
+	typename std::enable_if_t<std::is_integral_v<T>, void>
+	readInt(std::string_view name, T &out)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<void, DataFileField::Error> result = field.parseInt(out); !result.has_value()) {
+			DataFile::reportFatalFieldError(result.error(), filename_, name, field);
+		}
+	}
+
+	template <typename T>
+	typename std::enable_if_t<std::is_integral_v<T>, void>
+	readOptionalInt(std::string_view name, T &out)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (field.value().empty()) return;
+		if (tl::expected<void, DataFileField::Error> result = field.parseInt(out); !result.has_value()) {
+			DataFile::reportFatalFieldError(result.error(), filename_, name, field);
+		}
+	}
+
+	template <typename T, size_t N>
+	void readIntArray(std::string_view name, T (&out)[N])
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<void, DataFileField::Error> result = field.parseIntArray(out); !result.has_value()) {
+			DataFile::reportFatalFieldError(result.error(), filename_, name, field);
+		}
+	}
+
+	template <typename T>
+	typename std::enable_if_t<std::is_integral_v<T>, void>
+	readFixed6(std::string_view name, T &out)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<void, DataFileField::Error> result = field.parseFixed6(out); !result.has_value()) {
+			DataFile::reportFatalFieldError(result.error(), filename_, name, field);
+		}
+	}
+
+	void readBool(std::string_view name, bool &out)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<void, DataFileField::Error> result = field.parseBool(out); !result.has_value()) {
+			DataFile::reportFatalFieldError(result.error(), filename_, name, field);
+		}
+	}
+
+	void readString(std::string_view name, std::string &out)
+	{
+		advance();
+		out = (*it_).value();
+	}
+
+	template <typename T, typename F>
+	void read(std::string_view name, T &out, F &&parseFn)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<T, std::string> result = parseFn(field.value()); result.has_value()) {
+			out = *std::move(result);
+		} else {
+			DataFile::reportFatalFieldError(DataFileField::Error::InvalidValue, filename_, name, field, result.error());
+		}
+	}
+
+	template <typename T, typename F>
+	void readEnumList(std::string_view name, T &out, F &&parseFn)
+	{
+		advance();
+		DataFileField field = *it_;
+		if (tl::expected<void, std::string> result = field.parseEnumList(out, std::forward<F>(parseFn)); !result.has_value()) {
+			DataFile::reportFatalFieldError(DataFileField::Error::InvalidValue, filename_, name, field, result.error());
+		}
+	}
+
+	std::string_view value()
+	{
+		advance();
+		needsIncrement_ = false;
+		return (*it_).value();
+	}
+
+	void advance();
+
+private:
+	FieldIterator it_;
+	const FieldIterator end_;
+	std::string_view filename_;
+	bool needsIncrement_ = false;
+};
+
+} // namespace devilution