zir is a command line tool that realizes to write macros in any scripts into any languages.
See an example. (The macro is written in Ruby)

#include<stdio.h>

int main(){
  <-@macro puts "double a = #{Math::PI};" ->
  printf("PI is %f!\n", a);
  return 0;
}

This file will be expanded by zir like

#include<stdio.h>

int main(){
  double a = 3.141592653589793;
  printf("PI is %f!\n", a);
  return 0;
}

The result is PI is 3.141593!. 😄 You can find other samples at here.

zir is written in Crystal. So you need the environment. After that, clone this project and build by

shards build

Now you can find an executable binary at zir/bin/zir

1. Search zir files (such as sample.c.z)
2. Collect macros from the files
3. Create temporary files to be executed
4. Execute the scripts
5. Embed the result into the files (such as sample.c)

zir.yaml is a configuration file to execute zir. You must put it on a root of your project. zir.yaml is consists of 3 parts.

Specify files to be expanded in targets. The files must end with .z. .z will be removed from the name of expanded files. So sample.c.z will be sample.c.

targets: # An example
  - sample.c.z

Tell me how to execute the macros in ids. It need identifier and command line sample. @file will be replaced to a temporary executable.

# 'macro' is an identifier and `ruby some_temporary_executable` will be executed
ids:
  macro: ruby @file

What to execute at finally?

finally:
  gcc -o a.out sample.c

Here is a fully example.

targets:
  - sample.c.z
  
ids:
  macro: ruby @file

finally:
  gcc -o a.out sample.c  

The structure of macros is here.

<-@id your_code_here ->

All macros are sandwiched by <- ->. In the above example, @ is called mark and it can be % as well. id is an identifier which is defined in zir.yaml. Puts your code at your_code_here.

There are 2 types of macros and each of them has their mark.

First one is print macro that will be embeded into a source code. The mark of the print macro is @. Print macro shouldn't contain any logics but just print out variables. Here is an example of it.

<-@id puts "a" ->

Second one is logic macro that contains logics only. So This will print out nothing. Logic macros affect to the print macros which have same id with it.

<-%id0 a = 10 ->
<-%id1 a += 1 ->
<-@id0 puts a ->

So the result of this will be 10. See sample projects to know how to write these macros.

Basically, you just run zir run at root of your project. If you want to clean all temporary files, you can do it by zir clean. If you need a sample of zir.yaml, you can get it by zir init.

-c DEPTH or --cealn=DEPTH options help you to debug. You can specify which files to keep or to delete. DEPTH can be 0 to 2. If you specify 0, zir will keep all temporary files. Intermediate executable scripts are in .zir directory. 1 is default value that delete .zir directory but keep expanded files. So when you expand sample.c.z, expanded sample.c will remain. 2 will delete all files created by zir. (Delete sample.c in the previous case.)

zir -h will show you more options.

1. Fork it ( https://github.com/tbrand/zir/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

• tbrand Taichiro Suzuki - creator, maintainer