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Merged
Spartan322 merged 1 commit into from
Oct 16, 2025
Merged

Add fmt::formatter for LineObject #91

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102 changes: 101 additions & 1 deletion include/openvic-dataloader/csv/LineObject.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,9 @@

#include <openvic-dataloader/detail/Constexpr.hpp>

#include <fmt/base.h>
#include <fmt/format.h>

namespace ovdl::csv {
/// LineObject should be able to recognize the differences between:
/// Input -> Indexes == ""
Expand Down Expand Up @@ -168,4 +171,101 @@ namespace ovdl::csv {
}
return stream;
}
}
}

// Supports s<char> for designating a separator, including s{{ and s}} to escape brackets
// Also supports s{} for dynamic separator which supports multi-character separators
template<>
struct fmt::formatter<ovdl::csv::LineObject> : formatter<string_view> {
struct {
arg_id_kind kind = arg_id_kind::none;
detail::arg_ref<char> ref;
std::string value = ";";
} sep_spec {};

constexpr format_parse_context::iterator parse(format_parse_context& ctx) {
auto it = ctx.begin(), end = ctx.end();
if (it == end || *ctx.begin() == '}') {
return it;
}

if (*it == 's') {
++it;

if (*it == '{') {
++it;

if (*it == '{') {
++it;
sep_spec.value = { it, it + 1 };
} else if (*it == '}') {
++it;
sep_spec.ref = ctx.next_arg_id();
sep_spec.kind = arg_id_kind::index;
} else {
it = detail::parse_arg_id(it, end, detail::dynamic_spec_handler<char> { ctx, sep_spec.ref, sep_spec.kind });
}
} else if (*it == '}') {
++it;

if (*it != '}') {
report_error("invalid format string");
return it;
}
} else {
sep_spec.value = { it, it + 1 };
++it;
}
}

return it;
}

struct separator_spec_getter {
template<typename T, FMT_ENABLE_IF(detail::is_std_string_like<T>::value)>
constexpr auto operator()(T value) -> string_view {
return value;
}

constexpr auto operator()(const char* value) -> string_view {
return value;
}

template<typename T, FMT_ENABLE_IF(!detail::is_std_string_like<T>::value)>
constexpr auto operator()(T) -> string_view {
report_error("separator is not string-like");
return {};
}
};

format_context::iterator format(ovdl::csv::LineObject line, format_context& ctx) const {
string_view separator = sep_spec.value;
if (sep_spec.kind != arg_id_kind::none) {
auto arg = sep_spec.kind == arg_id_kind::index ? ctx.arg(sep_spec.ref.index) : ctx.arg(sep_spec.ref.name);
if (!arg) {
report_error("argument not found");
}
separator = arg.visit(separator_spec_getter {});
}

auto out = ctx.out();
ovdl::csv::LineObject::position_type sep_index = 0;
for (const auto& [pos, val] : line) {
while (sep_index < pos) {
out = detail::write<char>(out, separator);
ctx.advance_to(out);
sep_index++;
}
if (std::any_of(val.begin(), val.end(), [&](char c) { return (separator.size() == 1 && c == separator[0]) || std::isspace(c); })) {
out = detail::write<char>(out, '"');
ctx.advance_to(out);
out = formatter<string_view>::format(val, ctx);
out = detail::write<char>(out, '"');
ctx.advance_to(out);
} else {
out = formatter<string_view>::format(val, ctx);
}
}
return out;
}
};
30 changes: 30 additions & 0 deletions tests/src/csv/LineObject.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == ""sv);
}

SECTION("fmt to_string") {
CHECK(fmt::to_string(line) == ""sv);
}
}

SECTION("no prefix") {
Expand All @@ -50,6 +54,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == "a;b;c"sv);
}

SECTION("fmt to_string") {
CHECK(fmt::to_string(line) == "a;b;c"sv);
}
}

SECTION("no suffix") {
Expand Down Expand Up @@ -88,6 +96,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == ";a;b;c"sv);
}

SECTION("fmt to_string") {
CHECK(fmt::to_string(line) == ";a;b;c"sv);
}
}

SECTION("prefix and suffix with spaces") {
Expand All @@ -112,6 +124,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == ";\"a b\";\"c d\";\"e f\""sv);
}

SECTION("fmt to_string") {
CHECK(fmt::to_string(line) == ";\"a b\";\"c d\";\"e f\""sv);
}
}

SECTION("prefix and suffix with separators") {
Expand All @@ -136,6 +152,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == ";\"a;b\";\"c;d\";\"e;f\""sv);
}

SECTION("fmt to_string") {
CHECK(fmt::to_string(line) == ";\"a;b\";\"c;d\";\"e;f\""sv);
}
}

SECTION("prefix and suffix with custom char separator") {
Expand All @@ -151,6 +171,8 @@ TEST_CASE("LineObject", "[line-object]") {
ss << line.use_sep("|") << std::flush;

CHECK(ss.str() == "|a;b|c;d|e;f"sv);

CHECK(fmt::format("{:s|}", line) == "|a;b|c;d|e;f"sv);
}

SECTION("prefix and suffix with custom char separator and containing the separator") {
Expand All @@ -175,6 +197,10 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == "|\"a|b\"|\"c|d\"|\"e|f\""sv);
}

SECTION("fmt format") {
CHECK(fmt::format("{:s|}", line) == "|\"a|b\"|\"c|d\"|\"e|f\""sv);
}
}

SECTION("prefix and suffix with custom string_view separator") {
Expand All @@ -192,5 +218,9 @@ TEST_CASE("LineObject", "[line-object]") {

CHECK(ss.str() == "heya;bheyc;dheye;f"sv);
}

SECTION("fmt format") {
CHECK(fmt::format("{:s{}}", line, "hey") == "heya;bheyc;dheye;f"sv);
}
}
}