Why does ddlog -i tutorial.dl generate 78 files / 27k sloc?

[infogulch]

Hi! I've never used ddlog before but it looks pretty neat based on the readme. I wanted to browse the rust code that is generated based on a .dl schema, but it seems that's not kept checked-in to this repo so I had to download and generate it myself. I guess I understand why...

➜ ddlog -i tutorial.dl    # note: the --no-staticlib option seemed to make no difference

➜ cloc tutorial_ddlog/
      81 text files.
      80 unique files.                              
       4 files ignored.

github.com/AlDanial/cloc v 1.82  T=0.07 s (1142.5 files/s, 485689.4 lines/s)
-------------------------------------------------------------------------------
Language                     files          blank        comment           code
-------------------------------------------------------------------------------
Rust                            59           2380           2220          26305
TOML                            17             70             12            488
C/C++ Header                     1            139           1233            263
C                                1              5              6             37
-------------------------------------------------------------------------------
SUM:                            78           2594           3471          27093
-------------------------------------------------------------------------------

➜ find tutorial_ddlog/ -type d
tutorial_ddlog/
tutorial_ddlog/src
tutorial_ddlog/types
tutorial_ddlog/types/ddlog_std
tutorial_ddlog/types/inspect_log
tutorial_ddlog/types/internment
tutorial_ddlog/types/ddlog_log
tutorial_ddlog/types/vec
tutorial_ddlog/types/ddlog_rt
tutorial_ddlog/types/debug
tutorial_ddlog/types/ddlog_bigint
tutorial_ddlog/types/group
tutorial_ddlog/ovsdb
tutorial_ddlog/differential_datalog
tutorial_ddlog/differential_datalog/src
tutorial_ddlog/differential_datalog/src/render
tutorial_ddlog/differential_datalog/src/flatbuf
tutorial_ddlog/differential_datalog/src/dataflow
tutorial_ddlog/differential_datalog/src/record
tutorial_ddlog/differential_datalog/src/api
tutorial_ddlog/differential_datalog/src/program
tutorial_ddlog/differential_datalog/src/ddval
tutorial_ddlog/cmd_parser
tutorial_ddlog/.cargo
tutorial_ddlog/ddlog_derive
tutorial_ddlog/ddlog_derive/src
tutorial_ddlog/differential_datalog_test

It seems all the relevant code is in ./src/lib.rs and ./types/tutorial.rs which are a few thousand loc each, totally expected for code generated from such a comprehensive tutorial (over 750 lines by itself!).

What confuses me is that none of these other libraries seem to be directly related to the tutorial.dl file, but instead look like recursively vendored dependencies for the generated code. Why are dependencies vendored as part of the output?

[ryzhyk]

You're right. All this code that is not auto-generated should live either on crates.io or in the DDlog installation directory. This is on my todo list :)

[infogulch]

Ok, cool, thanks for responding. 😄

Have you considered trying to generate code on-the-fly during compilation by reading the .dl file in build.rs? E.g. build script examples. That would be Pretty Neat (tm) if the ddlog code is intended to be integrated as a library into a bigger project.

[ryzhyk]

We tend to write shell scripts or use cargo make, but build.rs might work too.