Console pretty printer for tabulated data

Pretty is a very lightweight cross-platform C++20 library for pretty formatting and pretty printing tabular data to the standard output of the program.

Tags: C++ pretty table, print table in C++, table formatting, tabulated output, console output, pretty formatting.

How to use

Visual Studio, projects and solutions

The library was tested with Visual C++/Visual Studio Version 17.5.1:

Copy unicode.ixx, pretty-impl.ixx, pretty.ixx to your project, include them as Existing Items.
Compile the files as module interface files. In Visual Studio, go to file Properties, Property Pages > C/C++ > Advanced, set Compile As to Compile as C++ Module Code (/interface ) for all the three files.
Go to project Properties, Property Pages > General, set C++ Language Standard to Standard ISO C++20 Standard (/std:c++20).
Go to project Properties, Property Pages > C/C++ > Command Line. In Additional Options, add
```
/utf-8
```
You are ready to use the API.

Clang

The library was tested with clang version 15.0.7:

Copy unicode.ixx, pretty-impl.ixx, pretty.ixx to your project directory.
Go to your project directory:
```
cd <your_project_dir>
```

The following command prebuilds the library modules:

clang++-15 -std=c++20 -Wall -O3 -fprebuilt-module-path=. -xc++-module unicode.ixx pretty-impl.ixx pretty.ixx --precompile

The following command builds a console test program for the library:
```
clang++-15 -std=c++20 -Wall -O3 -s -fprebuilt-module-path=. main.cpp unicode.pcm pretty-impl.pcm pretty.pcm
```
main.cpp in the command above is taken from the library and contains tests.
You are ready to use the API.

GCC

GCC C++ versions 11,12,13 were all tried. Versions 12 and 13 were unable to build the project due to internal compiler errors. Version 11 required to introduce some weird changes to the source code and to stop using some unsupported features like module:private, after which GCC managed to build an executable. The executable crashed with a segmentation fault at startup, without printing anything. This section will be updated when GCC catches up.

CMake

CMake support for C++20 modules is very experimental and is not ready for production.

The library provides a temporary CMake-compatible solution without C++20 modules, pretty.cpp and pretty.h. The support for these files will be dropped in the future in favor of modules.

pretty/Impl/CMakeLists.txt builds the library as an object file.

pretty/tests/CMakeLists.txt builds tests.

Successfully tested with

Clang 15.0.7, Linux x64
GCC 12.2.1, Linux x64
Visual Studio 17.5.3, Windows 10 x64

If you want to use CMake with Visual Studio, use the built-in Visual Studio support for CMake

On Linux, an easy way to use CMake is via Visual Studio Code with C/C++ Extension Pack and CMake Tools extensions. A C++ compiler and ninja need to be installed separately in a way specific to your Linux distribution.

API

All the detailed examples from this section can be found in main.cpp.

Import module pretty:

import pretty;

and you are ready to use the API.

How to populate tables with data

Instantiate pretty::Table and call its functions. pretty::Table can grow at runtime by appending new rows and/or columns in any order. It is possible to add some rows first, then some columns to the rows, then again rows:

const auto table = pretty::Table()
			.addRow("r1")
			.addRow("r2")
			.addCol({ "c1", "c2" })
			.addRow("r3", "r3");

The code above produces the following table:

┌────┬────┐
│ r1 │ c1 │
│ r2 │ c2 │
│ r3 │ r3 │
└────┴────┘

pretty::Table supports only regular tables - the number of columns is the same in each row.

When adding new rows, it is important to make sure that the number of columns in appended row[s] matches the current number of columns in the table.

When adding new columns, it is important to make sure that the number of rows in appended column[s] matches the current number of rows in the table.

addRow(…) is overloaded and accepts either std::vector<std::string> or a variadic pack of arguments convertible to std::string.

addCol(…) accepts only std::vector<std::string>.

addColumns(ColN numCols) and addRows(RowN numRows) allow to add the given number of empty columns and rows, respectively. The added cells are empty and need to be populated programmatically by calling setText(RowN row, ColN col, std::convertible_to<std::string> auto&& text):

auto table = pretty::Table()
			.addColumns(3)
			.addRows(2);

auto format = [](pretty::RowN r, pretty::ColN c)
{
	return std::to_string(r.val()) + "," + std::to_string(c.val());
};

pretty::RowN r{};
for (; r < table.numRows(); ++r)
	for (pretty::ColN c{}; c < table.numColumns(); ++c)
		table.setText(r, c, format(r, c));

The above code produces:

┌─────┬─────┬─────┐
│ 0,0 │ 0,1 │ 0,2 │
│ 1,0 │ 1,1 │ 1,2 │
└─────┴─────┴─────┘

Now let's add 3 additional rows to the previous table:

table.addRows(3);
for (;r < table.numRows(); ++r)
    for (pretty::ColN c{};c < table.numColumns(); ++c)
        table.setText(r, c, format(r, c));

which produces:

┌─────┬─────┬─────┐
│ 0,0 │ 0,1 │ 0,2 │
│ 1,0 │ 1,1 │ 1,2 │
│ 2,0 │ 2,1 │ 2,2 │
│ 3,0 │ 3,1 │ 3,2 │
│ 4,0 │ 4,1 │ 4,2 │
└─────┴─────┴─────┘

How to format and print tables

Instantiate pretty::Printer and configure it as required:

pretty::Printer print;

Frame styles

Basic

print.frame(pretty::FrameStyle::Basic);

+----------------+-----------+
| Country        | UN Region |
+----------------+-----------+
| World          | -         |
| United States  | Americas  |
| China          | Asia      |
| Japan          | Asia      |
| Germany        | Europe    |
| India          | Asia      |
| United Kingdom | Europe    |
| France         | Europe    |
+----------------+-----------+

Line

print.frame(pretty::FrameStyle::Line);

┌────────────────┬───────────┐
│ Country        │ UN Region │
├────────────────┼───────────┤
│ World          │ -         │
│ United States  │ Americas  │
│ China          │ Asia      │
│ Japan          │ Asia      │
│ Germany        │ Europe    │
│ India          │ Asia      │
│ United Kingdom │ Europe    │
│ France         │ Europe    │
└────────────────┴───────────┘

LineRounded

print.frame(pretty::FrameStyle::LineRounded);

╭────────────────┬───────────╮
│ Country        │ UN Region │
├────────────────┼───────────┤
│ World          │ -         │
│ United States  │ Americas  │
│ China          │ Asia      │
│ Japan          │ Asia      │
│ Germany        │ Europe    │
│ India          │ Asia      │
│ United Kingdom │ Europe    │
│ France         │ Europe    │
╰────────────────┴───────────╯

ThickLine

print.frame(pretty::FrameStyle::ThickLine);

┏━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┓
┃ Country        ┃ UN Region ┃
┣━━━━━━━━━━━━━━━━╋━━━━━━━━━━━┫
┃ World          ┃ -         ┃
┃ United States  ┃ Americas  ┃
┃ China          ┃ Asia      ┃
┃ Japan          ┃ Asia      ┃
┃ Germany        ┃ Europe    ┃
┃ India          ┃ Asia      ┃
┃ United Kingdom ┃ Europe    ┃
┃ France         ┃ Europe    ┃
┗━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┛

DoubleLine

print.frame(pretty::FrameStyle::DoubleLine);

╔════════════════╦═══════════╗
║ Country        ║ UN Region ║
╠════════════════╬═══════════╣
║ World          ║ -         ║
║ United States  ║ Americas  ║
║ China          ║ Asia      ║
║ Japan          ║ Asia      ║
║ Germany        ║ Europe    ║
║ India          ║ Asia      ║
║ United Kingdom ║ Europe    ║
║ France         ║ Europe    ║
╚════════════════╩═══════════╝

Minimal

print.frame(pretty::FrameStyle::Minimal);

  Country          UN Region
 ---------------- -----------
  World            -
  United States    Americas
  China            Asia
  Japan            Asia
  Germany          Europe
  India            Asia
  United Kingdom   Europe
  France           Europe

Padding

padding(n) allows to set the horizontal distance from the text to the cell border:

print.padding(0);

┌──────────────┬─────────┐
│Country       │UN Region│
├──────────────┼─────────┤
│World         │-        │
│United States │Americas │
│China         │Asia     │
│Japan         │Asia     │
│Germany       │Europe   │
│India         │Asia     │
│United Kingdom│Europe   │
│France        │Europe   │
└──────────────┴─────────┘

Header separator

headerSeparator(bool show) shows or hides horizontal separator line for the first row ("header"). Otherwise, the header row does not differ from other rows:

print.headerSeparator(false);

┌──────────────┬─────────┐
│Country       │UN Region│
│World         │-        │
│United States │Americas │
│China         │Asia     │
│Japan         │Asia     │
│Germany       │Europe   │
│India         │Asia     │
│United Kingdom│Europe   │
│France        │Europe   │
└──────────────┴─────────┘

Printer output

Once pretty::Printer is configured, call [[nodiscard]]std::string toString(const Table& t) const to obtain a string with a pretty-formatted table.

If you need to print to the standard output, the operator<< is overloaded for pretty::Printer:

pretty::Printer print;
print.frame(pretty::FrameStyle::Basic);
cout << print(table);

pretty::Printer also overloads the operator() to allow the concise syntax for data loading like in the code above.

On Windows, printing to the standard output requires enabling UTF8 for the console, which is done by the overloaded operator<<. Otherwise, you may just use toString(...) and then manually print the obtained string to whatever stream/file you need.

Unicode

The library is fully Unicode-aware. The data in all cells is of type std::string which is expected to be encoded in UTF8. When formatting the table, pretty::Printer takes into account the visible/display/column width of cell text, so tables are correctly formatted even with hieroglyphs and emojis:

For correct Unicode rendering it is important that:

The used OS and terminal application support Unicode
The selected terminal font supports Unicode and all the codepoints that you need to print

On Linux, hieroglyphic and emoji codepoints are rendered much better.

On Windows, using Windows Terminal is highly recommended, as cmd.exe does not support rendering some codepoints even after enabling UTF8 and selecting a Unicode font, see https://stackoverflow.com/a/67510140. Windows Terminal renders many emojis correctly

, but not all:

Report issues at Windows Terminal

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

readme.md

readme.md

Console pretty printer for tabulated data

How to use

Visual Studio, projects and solutions

Clang

GCC

CMake

API

How to populate tables with data

How to format and print tables

Frame styles

Padding

Header separator

Printer output

Unicode

Files

readme.md

Latest commit

History

readme.md

File metadata and controls

Console pretty printer for tabulated data

How to use

Visual Studio, projects and solutions

Clang

GCC

CMake

API

How to populate tables with data

How to format and print tables

Frame styles

Padding

Header separator

Printer output

Unicode