IO Reader GENerator

Description

Iorgen is a multi languages code generator to parse a predefined input template. The user writes a YAML describing the input, and Iorgen will generate the code to read this input from stdin, in all supported languages.

The list of currently supported languages is: C, C++, C#, D, Go, Haskell, Java, Javascript, Julia, Kotlin, Lua, Ocaml, Pascal, Perl, PHP, Prolog, Python, Ruby, Rust, Scheme, Zig. A Markdown description of the input in English and French can also be generated.

Installation

You can install iorgen in a virtual environment like this:

git clone git@gitlab.com:prologin/tech/tools/iorgen.git
cd iorgen
python3 -m venv .venv
source .venv/bin/activate
pip3 install poetry
poetry install

You can then run it with the iorgen command.

Testing the languages

You should be able to trust that Iorgen will generate valid files. But if you want to be sure that those files are valid, and want to generate the test suite for instance, you will have to install lots of compilers.

The complete dependencies for Archlinux are:

pacman -S --needed python-yaml fpc gambit-c gcc gdc ghc go jdk-openjdk julia \
    kotlin lua mono nodejs ocaml perl php ruby rust swi-prolog

For Debian based distros (tested on Debian 10, 11, 12 and Ubuntu 18.04, 20.04, 22.04) (see limitations below):

sudo apt install python3-yaml default-jdk-headless fp-compiler g++ gambc gcc \
    gdc ghc golang-go julia kotlin lua5.3 mono-mcs nodejs ocaml-nox perl \
    php-cli ruby rustc swi-prolog-nox

Issues with some Debian/Ubuntu versions:

• There might not be a julia package. You’ll have to install it from their website.
• The kotlin package only exists starting from Debian 12 and Ubuntu 22.04.
• The compilers must not be too old. For instance for Ocaml you need at least version 4.06, which is more recent that the default version in Ubuntu 18.04 and Debian 10.

Usage

Make sure python (version 3.9 and above) and python-yaml are installed on your computer and run python3 -m iorgen gen-stubs input.yaml. This will generate all languages parsers in a skeleton folder, and a input-subject-io-stub.md describing the input (in French by default).

Iorgen functionalities are separated in the following subcommands:

gen-stubs (Stubs generation)

This subcommand allows you to generate languages parsers (skeletons) and a markdown subject stub.

You are able to generate these for a single YAML input file or multiple files at once.

By default, the languages parsers will be generated in the skeleton directory. However, you can change the output directory with the --output_dir option.

You can also chose to generate all files in the parent directory of the YAML input file with the --same_dir flag, by default it will generate the files in the current working directory. Note that the generated markdown stub will be named subject-io-stub.md when using --same_dir flag, otherwise it will be prefixed with the YAML input file name like this: <prefix>-subject-io-stub.md.

Examples

1. Generate problem stubs in the current working directory

iorgen gen-stubs 42.yaml

2. Generate multiple problem stubs at once

iorgen gen-stubs 42/42.iorgen loueur/loueur.yaml

You can also use your shell globs!

iorgen gen-stubs **/*.yaml

3. Generate all stubs next to their YAML input file

iorgen gen-stubs --same_dir **/*.yaml

gen-input (Random input generation)

This subcommand allows you to generate a valid raw input based on your YAML input file.

You can specify a value, the minimum value or the maximum value of a variable for the generated raw input with the --specify option. NAME VALUE will set the value. NAME_max VALUE the maximum value and NAME_min VALUE the minimum value.

You can also treat raw input as in performance mode by using the --perf_mode flag. The performance mode is a mode where the constraints are different, usually the integers are bigger.

Example

iorgen gen-input -s N_max 10 i 42 -- example.yaml

validate (Raw input file validation)

This subcommand allows you to check raw input files against a YAML input file.

You can also check raw inputs made generated for performance tests by using the --perf_mode flag.

1. Validate a single file

iorgen validate 42.iorgen test/01.in

2. Validate multiple files

iorgen validate 42.iorgen test/01.in test/02.in test/03.in

or using globs

iorgen validate 42.iorgen 'test/*.in'

or using shell globs

iorgen validate 42.iorgen test/*.in

run (Parsers check)

This subcommand allows you to check that the parsers generated by iorgen properly parse and print the input they are fed with.

You may want to use the --languages option to specify the list of tested languages if you don't have all of them installed. See this section to know how to test against all languages.

Example

iorgen run 42.iorgen test/test01.in

Input format

Types

Iorgen can use the following types:

• Integer: the default integer type for the language
• Float: a double precision floating-point number, often called "double" in languages; see below for more details about float support
• Char: can be either a byte, or a string depending of the language
• String: a string with a given maximum size
• List: an array, list, vector… of a given size, containing one of the Iorgen supported types
• Struct: a C like struct, or a map which have strings as keys; each field can have any of Iorgen supported types (except the exact same struct)

Float support

Iorgen supports floating-point numbers, but beware they are not as easy to use as integers. Here are the constrains when using floats:

• A maximum of 15 digts can be used to write a float (in decimal notation). This means that, with the minus and dot sign, a float can take up to 17 characters. Here are some example values: 123456789012345, 12345.6789012345, 0.00123456789012, but of course the number can take less digits, like 3.5 or 0.03.
• When writing the floats in the input that will be fed in STDIN, a unique format should be respected, and that is the ".15g" format from C. Concretly, combined with the first constraint, this means that any number that starts with 0.0000 (or -0.0000), should be written in scientific notation instead. For example, 1e-5, 3.924e-07. Also, no trailing dot, no trailing 0, and no unnecessary 0 before the number, except in the exponent if it smaller than 2 digits. Conforming to the ".15g" C format in necessary for Iorgen to be able to test that the parser are working properly (the run command).

Format

The input is described in YAML, and must have the following format:

• A "function_name" field, containing the name of the generated function
• A "subject" field, containing a string (can be several paragraphs) describing what the input is about (will no be used in generated code)
• An "ouput" field, containing a string (can be several paragraphs) describing what the end user have to do with the parsed input
• An "input" field, containing a list of variables. Each variable is a map with the following fields:
  • A "type" field, containing a string (see the type syntax below)
  • A "name" field, containing a string: the variable’s name
  • A "comment" field, containing a string: a description of the variable
  • An optional "min" field, if the variable is a integer, a float, or a list (or list or list, or list of list of list, etc) of integers or floats. This will be the minimal value possible for this variable. This is used in the Markdown generator to show the constraints, and in some langages generators to check if the size of a list or a string is garantied to be not null. The "min" field can either be an integer, a float (if the variable is of type float), or a variable name.
  • An optional "max" field (similar to the "min" one).
  • An optional "min_perf" field: like the "min" one, but only used in the case of performance cases, often meaning that the variable will have a very big value.
  • An optional "max_perf" field (similar to the "min_perf" one).
  • An optional "choices" field, if the variable is an integer, a float or a char, or a list (or list of list, etc) of integers, floats or chars (for this definition a string is considered as a list of chars). "choices" is a list of values possible for this integer, float or char. If this list is not empty, then the "min" fields and similar fields will be ignored.
  • An optional "format" field, containing a string; see the manual formatting section to know more.
• An optional "structs" field, if your input uses structs, a list of structs. Each struct is a map with the following fields:
  • A "name" field, containing a string: the struct’s name
  • A "comment" field, containing a string: a description of the struct
  • A "fields" field, containing a list of the struct’s fields (same syntax as "input")

Syntax

Any "name" field (or "function_name") can hold any alphanumic character or spaces, but must start with a letter, and can not have trailing whitespaces. You do not have to worry about the name beeing a language’s keyword: it will automatically be modified if that is the case, usually by adding a trailing underscore.

A "comment" field can hold any character other than a newline. For now, strings that end comments in some languages, such as */ should be avoided. A protection against this will be added in a later version.

A "type" field must have one of the following format int, float, char, str(size), List[type](size), @structname. You must replace size, type and structname following this guidelines:

• size can be either a number, or a variable name. If it is a variable name, it must be a toplevel one (i.e. in the "input" list), and must have been declared before use. One exception: you can use a struct with two fields: one integer, and a other a type whose size is the first field. For strings, the given size, in the maximum size the string will have, but it could be less.
• type can be any valid type, even an other list
• structname is the name of a struct, as declared in the "name" field of "structs"

Manual formatting

Iorgen is supposed to choose how the input should be. For instance, each integer variable stands on its own line. Lists of integers however put them all on the same line. There are reasons for this: one variable per line is easier to parse on most languages; putting integers on the same line keeps inputs shorter. Anyway, even if you don't agree with those choices, you should not really care and just go with how Iorgen does things.

If you have the choice, don't try to change the defaults, just go with the flow: it is how Iorgen was meant to work and it is well tested with those defaults. However if your input is already set is stone and you can not change it, Iorgen provides a few options to tweak the input layout.

• You can have several integers variables on the same line. All variables must be integers, and follow each other in the input list. For every of the variables but the last one put the "format": no_endline field.
• You can have a list of integers with one entry per line, instead of having all the integers on the same line. This currently works for a simple List[int], not for any nested type. Use the "format": force_newlines field.

Example

function_name: example
subject: This input is an example for Iorgen's README
structs:
    - name: a struct
      comment: A struct for the example
      fields:
          - type: int
            name: integer
            comment: an integer
            choices: [-4, 42, 1337]
          - type: char
            name: character
            comment: a char
            choices: [a, b, c]
input:
    - type: int
      name: N
      comment: a number, used as a size
      min: 1
      max: 10
      max_perf: 10000
    - type: List[@a struct](N)
      name: list
      comment: a list of structs
output: In a real life scenario, you will describe here what you want the end
    user to do with this generated code

If you want to generate the C code for parsing this kind of input, run python3 -m iorgen gen-stubs -l c example.yaml, and you will get the following skeleton/example.c:

#include <stdio.h>
#include <stdlib.h>

/// A struct for the example
struct a_struct {
    int integer; ///< an integer
    char character; ///< a char
};

/// \param n a number, used as a size
/// \param list a list of structs
void example(int n, struct a_struct* list) {
    /* TODO In a real life scenario, you will describe here what you want the
    end user to do with this generated code */
}

int main() {
    int n;
    scanf("%d", &n);
    struct a_struct* list = (struct a_struct*)malloc(n * sizeof(struct a_struct));
    for (int i = 0; i < n; ++i) {
        scanf("%d %c", &list[i].integer, &list[i].character);
    }
    example(n, list);

    return 0;
}

You can see every other thing that Iorgen can generate in the test samples; you can find parsers for lots of languages, and also a generated description of the input in Markdown.