Raku Land



Data Query Workflows


This Raku (Perl 6) package has grammar and action classes for the parsing and interpretation of natural Domain Specific Language (DSL) commands that specify data queries in the style of Standard Query Language (SQL) or RStudio's library tidyverse.

The interpreters (actions) have as targets different programming languages (and packages in them.)

The currently implemented programming-language-and-package targets are: Julia::DataFrames, Mathematica, Python::pandas, R::base, R::tidyverse, Raku::Reshapers.

There are also interpreters to natural languages: Bulgarian, English, Korean, Russian, Spanish.


Zef ecosystem:

zef install DSL::English::DataQueryWorkflows


zef install https://github.com/antononcube/Raku-DSL-English-DataQueryWorkflows.git

Current state

The following diagram:

Remark: The grammar of this package is extended to parse Bulgarian DSL commands with the package "DSL::Bulgarian", [AAp5].

Workflows considered

The following flow-chart encompasses the data transformations workflows we consider:

Here are some properties of the methodology / flow chart:

In the world of the programming language R the orange blocks represent the so called Split-Transform-Combine pattern; see the article "The Split-Apply-Combine Strategy for Data Analysis" by Hadley Wickham, [HW1].

For more data query workflows design details see the article "Introduction to data wrangling with Raku", [AA1] or its translation (and upgrade) in Bulgarian, [AA2].


Here is example code:

use DSL::English::DataQueryWorkflows;

say ToDataQueryWorkflowCode('select mass & height', 'R-tidyverse');
# dplyr::select(mass, height)

Here is a longer data wrangling command:

my $command = 'use starwars;
select species, mass & height;
group by species;
arrange by the variables species and mass descending';
# use starwars;
# select species, mass & height;
# group by species;
# arrange by the variables species and mass descending

Here we translate that command into executable code for Julia, Mathematica, Python, R, and Raku:

{say $_.key,  ":\n", $_.value, "\n"} for <Julia Mathematica Python R R::tidyverse Raku>.map({ $_ => ToDataQueryWorkflowCode($command, $_ ) });
# Julia:
# obj = starwars
# obj = obj[ : , [:species, :mass, :height]]
# obj = groupby( obj, [:species] )
# obj = sort( obj, [:species, :mass], rev=true )
# Mathematica:
# obj = starwars
# obj = Map[ KeyTake[ #, {"species", "mass", "height"} ]&, obj]
# obj = GroupBy[ obj, #["species"]& ]
# obj = ReverseSortBy[ #, {#["species"], #["mass"]}& ]& /@ obj
# Python:
# obj = starwars.copy()
# obj = obj[["species", "mass", "height"]]
# obj = obj.groupby(["species"])
# obj = obj.sort_values( ["species", "mass"], ascending = False )
# R:
# obj <- starwars ;
# obj <- obj[, c("species", "mass", "height")] ;
# obj <- split( x = obj, f = "species" ) ;
# obj <- obj[ rev(order(obj[ ,c("species", "mass")])), ]
# R::tidyverse:
# starwars %>%
# dplyr::select(species, mass, height) %>%
# dplyr::group_by(species) %>%
# dplyr::arrange(desc(species, mass))
# Raku:
# $obj = starwars ;
# $obj = select-columns($obj, ("species", "mass", "height") ) ;
# $obj = group-by($obj, "species") ;
# $obj = $obj>>.sort({ ($_{"species"}, $_{"mass"}) })>>.reverse

Here we translate to other human languages:

{say $_.key,  ":\n", $_.value, "\n"} for <Bulgarian English Korean Russian Spanish>.map({ $_ => ToDataQueryWorkflowCode($command, $_ ) });
# Bulgarian:
# използвай таблицата: starwars
# избери колоните: "species", "mass", "height"
# групирай с колоните: species
# сортирай в низходящ ред с колоните: "species", "mass"
# English:
# use the data table: starwars
# select the columns: "species", "mass", "height"
# group by the columns: species
# sort in descending order with the columns: "species", "mass"
# Korean:
# 테이블 사용: starwars
# "species", "mass", "height" 열 선택
# 열로 그룹화: species
# 열과 함께 내림차순으로 정렬: "species", "mass"
# Russian:
# использовать таблицу: starwars
# выбрать столбцы: "species", "mass", "height"
# групировать с колонками: species
# сортировать в порядке убывания по столбцам: "species", "mass"
# Spanish:
# utilizar la tabla: starwars
# escoger columnas: "species", "mass", "height"
# agrupar con columnas: "species"
# ordenar en orden descendente con columnas: "species", "mass"

Additional examples can be found in this file: DataQueryWorkflows-examples.raku.

Command line interface

The package provides the Command Line Interface (CLI) program ToDataQueryWorkflowCode. Here is its usage message:

> ToDataQueryWorkflowCode --help
  ToDataQueryWorkflowCode [-l|--language=<Str>] [-f|--format=<Str>] [--cmd|--clipboard-command=<Str>] [-c|--copy-to-clipboard] <target> <command> -- Easier target specification.
  ToDataQueryWorkflowCode [-t|--target=<Str>] [-l|--language=<Str>] [-f|--format=<Str>] [-c|--copy-to-clipboard] [--cmd|--clipboard-command=<Str>] <command> -- Translates natural language commands into data transformations programming code. If --clipboard-command is an empty string then the environment variables CLIPBOARDCOMMAND and CLIPBOARD_COMMAND are attempted. If those variables are not defined then 'pbcopy' is used on macOS, 'clip.exe' on Windows, and 'xclip -selection clipboard' on Linux.
    <target>                           Programming language.
    <command>                          A string with one or many commands (separated by ';').
    -l|--language=<Str>                The natural language to translate from. [default: 'English']
    -f|--format=<Str>                  The format of the output, one of 'automatic', 'code', 'hash', or 'raku'. [default: 'automatic']
    --cmd|--clipboard-command=<Str>    Clipboard command to use (if --copy-to-clipboard.) [default: '']
    -c|--copy-to-clipboard             Should the result be copied to the clipboard or not? [default: True]
    -t|--target=<Str>                  Target (programming language with optional library spec.) [default: 'R-tidyverse']

Here is an example invocation:

> ToDataQueryWorkflowCode Python "use the dataset dfTitanic; group by passengerSex; show counts"
obj = dfTitanic.copy()
obj = obj.groupby(["passengerSex"])

Remark: Note that by default an attempt is made to copy the result to the clipboard. If "--clipboard-command" is an empty string then the environment variables CLIPBOARD_COPY_COMMAND and CB_CP_CMD are attempted. If those environment variables are not defined then pbcopy is used on macOS, clip.exe on Windows, and xclip -selection clipboard on Linux.


There are three types of unit tests for:

  1. Parsing abilities; see example

  2. Interpretation into correct expected code; see example

  3. Data transformation correctness; see tests in:

The unit tests R-package [AAp2] can be used to test both R and Python translations and equivalence between them.

There is a similar WL package, [AAp3]. (The WL unit tests package can have unit tests for Julia, Python, R -- not implemented yet.)

On naming of translation packages

WL has a System context where usually the built-in functions reside. WL adepts know this, but others do not. (Every WL package provides a context for its functions.)

My naming convention for the translation files so far is <programming language>::<package name>. And I do not want to break that invariant.

Knowing the package is not essential when invoking the functions. For example ToDataQueryWorkflowCode[_,"R"] produces same results as ToDataQueryWorkflowCode[_,"R-base"], etc.


The original version of this Raku package was developed/hosted at [ AAp1 ].

A dedicated GitHub repository was made in order to make the installation with Raku's zef more direct. (As shown above.)




[AA1] Anton Antonov, "Introduction to data wrangling with Raku", (2021), RakuForPrediction at WordPress.

[AA2] Anton Antonov, "Увод в обработката на данни с Raku", (2022), RakuForPrediction at WordPress.

[HW1] Hadley Wickham, "The Split-Apply-Combine Strategy for Data Analysis", (2011), Journal of Statistical Software.


[AAp1] Anton Antonov, Data Query Workflows Raku Package , (2020), ConversationalAgents at GitHub/antononcube.

[AAp2] Anton Antonov, Data Query Workflows Tests, (2020), R-packages at GitHub/antononcube.

[AAp3] Anton Antonov, Data Query Workflows Mathematica Unit Tests, (2020), ConversationalAgents at GitHub/antononcube.

[AAp4] Anton Antonov, Data Query Workflows Python Unit Tests, (2020), ConversationalAgents at GitHub/antononcube.

[AAp5] Anton Antonov, DSL::Bulgarian Raku package, (2022), GitHub/antononcube.


[AAv1] Anton Antonov, "Multi-language Data-Wrangling Conversational Agent", (2020), Wolfram Technology Conference 2020, YouTube/Wolfram.

[AAv2] Anton Antonov, "Raku for Prediction", (2021), The Raku Conference 2021.

[AAv3] Anton Antonov, "Doing it like a Cro (Raku data wrangling Shortcuts demo)", (2021), Anton Antonov's channel at YouTube.

[AAv4] Anton Antonov, "FOSDEM2022 Multi language Data Wrangling and Acquisition Conversational Agents (in Raku)", (2022), Anton Antonov's channel at YouTube.

[AAv5] Anton Antonov, "Implementing Machine Learning algorithms in Raku" at TRC-2022 (2022), The Raku Conference 2022.