Thubi

English is my second language, so expect some grammar errors

Thubi is an esoteric language created by Ihope127, however he didn't implement this language, so I try to implement it.

Its official document is https://esolangs.org/wiki/Thubi.

Building

Requirements:

Make
GCC or Clang (Visual Studio is not tested)

To build Thubi interpretor, just type make in your favorite terminal, then you'll see thubi executable in bin folder.

To run Thubi program: (assume you are in top folder of this repo)

bin/thubi [Thubi program file]

To run Thue program: (assume you are in top folder of this repo)

bin/thubi -thue [Thue program file]

Examples

Example Thubi programs are in examples folders.

Notes

The document didn't say if digits in hexadecimal escape character (\xnn) should be uppercase or lowercase. My implementation accepts both uppercase and lowercase hexadecimal digits.
My implementation has some extensions:
1. output like in Thue
```
:<original string>
~<string to output>
```
  It will work like <original string>::=~<string to output> in Thue, except that you can use defined symbols in both side of the production rule.
2. input like in Thue
```
:<original string>
:::
```
  It will work like <original string>::=::: in Thue, except that you can use defined symbols in original string.
3. comments
  
  You can have comments in rule section of program.
  
  A comment is a line starting with #. However, you cannot have comments in initial program state section because they will be treated as normal initial strings. For example:
```
#This Thubi program outputs hello world
#This is a comment
# This is also a comment
:start
# a comment too
~hello world\n

# however, this is not a comment
start
# because here is initial program state section
```
4. multiline initial string
  
  When there are many lines of initial string, they will be concatenated.
  
  So the above example program has initial string # however, this is not a commentstart# because here is initial program state section

Todo

I think storing program string as flat array is not fast enough, because it has O(n) complexity for string replacing, n is the length of current program string. Maybe I'll switch to better data structure.