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Show HN: Bic – a C interpreter and API explorer

181 points by hexagonal-sun 7y ago

sshb 7y ago
Reminds me of CERN’s ROOT which has C/C++ interpreter https://root.cern.ch/ https://root.cern.ch/
- hexagonal-sun 7y ago
  Huh, I didn't know about that tool. Looking through the docs this looks impressive, especially since it can do C++ too.
- kzrdude 7y ago
  Their new repl is called cling: https://github.com/root-project/cling https://github.com/root-project/cling (They had an old one called C-INT or something like that).
- amirmasoudabdol 7y ago
  One of the biggest problem with these repl for complied languages is that they panic as soon as you rerun a command. `cling` integrates with Jupyter notebook too but as soon as you rerun a declaration of a variable, everything collapse and you have to reset the kernel. Maybe I didn’t dig deep enough and there is a way around this but if not, this is quite painful to deal with and a deal breaker.
  - sigjuice 7y ago
    So repeating something like 'int i = 42;' causes problems?
scandox 7y ago
I often looked for this and failed to find something that I could easily use. So I'm delighted to see this as a on/off C amateur and learner.
- hexagonal-sun 7y ago
  Thanks! It's still a work in progress but should hopefully help people to get to grips with C.
smhenderson 7y ago
This is really cool, nice work. I especially like the bit about putting a REPL statement in a source file to have it drop into bic. Seems like a quick and dirty way to debug without having to fire up gdb and such. Somewhere in between print statements and full on debugging. Thanks for sharing.
agumonkey 7y ago
I love that you have to #include how to exit :)
- airstrike 7y ago
  And people think exiting vim is hard! I suppose you could always quit abruptly, though...
- huhtenberg 7y ago
  Technically, you should be able to just call exit(1) because of the C's support for "implicit function declarations". With no prior exit() declaration, the C compiler would assume that "exit" is "int exit()", spit out the code to push whatever arguments are passed to it down the stack and then just call the damn thing. So, magically, it will all just work. Requires an older compiler though, C89 the latest.
  - jart 7y ago
    Modern GCC and Clang still support implicit functions. They just complain about it by default. (Mostly for reasons that shouldn't be entirely relevant to modern x86.)
emilfihlman 7y ago
Why is fputs returning 1?
- fit2rule 7y ago
  1 is a non-negative number. fputs() return nonnegative numbers on success...
  - emilfihlman 7y ago
    Ah yeah true, looked at the wrong part of a man page.
xvilka 7y ago
It lacks the syntax highlight. They could have used tree-sitter[1] for parsing, then the online highlight would be easier to implement. [1] https://github.com/tree-sitter/tree-sitter https://github.com/tree-sitter/tree-sitter
- israrkhan 7y ago
  perhaps you meant to include https://github.com/tree-sitter/tree-sitter https://github.com/tree-sitter/tree-sitter as reference.
  - xvilka 7y ago
    Oh, yes, clipboard mistake, thanks for the correction!
- hexagonal-sun 7y ago
  Agreed, syntax highlighting would be great. I was thinking about something akin to fish's syntax highlighting and completion with the REPL. I'll take a look at tree-sitter. If I get syntax highlighting for free then I'll take that!
- johnisgood 7y ago
  > Dependency-free so that the runtime library (which is written in pure C) can be embedded in any application What does dependency-free mean? I mean, it does depend on 128 crates. Do we typically not count those? By the way, I did `cargo build` and it failed at `#include "utf8proc.c"`. I have `libutf8proc` installed. Changing `.c` to `.h` solved it. It went past that part, only to get: - error: couldn't read cli/src/../../lib/binding_web/tree-sitter.js: No such file or directory (os error 2) - error: couldn't read cli/src/../../lib/binding_web/tree-sitter.wasm: No such file or directory (os error 2)
  - TkTech 7y ago
    The generator isn't dependency free, the parser it generates is.
israrkhan 7y ago
an integration with jupyter would be nice.
deleted 7y ago
[deleted]
fortran77 7y ago
In the late 80s there was a product called C-Terp, which I loved! Here's a link to a brief description: https://books.google.com/books?id=fHghpJa3va4C&lpg=PA167&ots=Tq9xCXDt76&dq=C-Terp%20c%20interpreter&pg=PA167#v=onepage&q=C-Terp%20c%20interpreter&f=false https://books.google.com/books?id=fHghpJa3va4C&lpg=PA167&ots... And, yes, I paid the $295 for it.
wrp 7y ago
Interactive C environments were popular for a while. I have collected information on several at the Computer History Museum. I actually have even more stuff that I never got around to uploading. You unfortunately need to make an account to see the pages. It was heavily attacked at one time and that was the admin's solution. Interactive C Environments http://www.softwarepreservation.org/projects/interactive_c http://www.softwarepreservation.org/projects/interactive_c
jart 7y ago
One cool trick for C REPLs is to grep the man page directory to automate those pesky #include lines, e.g. https://gist.github.com/jart/5d0934d26b52f38cad36 https://gist.github.com/jart/5d0934d26b52f38cad36 Another trick is to build with STABS and use objdump -g.
forpace 7y ago
One of the biggest problem with these repl for complied languages is that they panic as soon as you rerun a command. `cling` integrates with Jupyter notebook too but as soon as you rerun a declaration of a variable, everything collapse and you have to reset the kernel. Maybe I didn’t dig deep enough and there is a way around this but if not, this is quite painful to deal with and a deal breaker.

181 points by hexagonal-sun 7y ago

sshb 7y ago

Reminds me of CERN’s ROOT which has C/C++ interpreter https://root.cern.ch/ https://root.cern.ch/

hexagonal-sun 7y ago
Huh, I didn't know about that tool. Looking through the docs this looks impressive, especially since it can do C++ too.
kzrdude 7y ago
Their new repl is called cling: https://github.com/root-project/cling https://github.com/root-project/cling (They had an old one called C-INT or something like that).
amirmasoudabdol 7y ago
One of the biggest problem with these repl for complied languages is that they panic as soon as you rerun a command. `cling` integrates with Jupyter notebook too but as soon as you rerun a declaration of a variable, everything collapse and you have to reset the kernel. Maybe I didn’t dig deep enough and there is a way around this but if not, this is quite painful to deal with and a deal breaker.
- sigjuice 7y ago
  So repeating something like 'int i = 42;' causes problems?

scandox 7y ago

I often looked for this and failed to find something that I could easily use. So I'm delighted to see this as a on/off C amateur and learner.

hexagonal-sun 7y ago
Thanks! It's still a work in progress but should hopefully help people to get to grips with C.

smhenderson 7y ago

This is really cool, nice work. I especially like the bit about putting a REPL statement in a source file to have it drop into bic. Seems like a quick and dirty way to debug without having to fire up gdb and such. Somewhere in between print statements and full on debugging. Thanks for sharing.

agumonkey 7y ago

I love that you have to #include how to exit :)

airstrike 7y ago
And people think exiting vim is hard! I suppose you could always quit abruptly, though...
huhtenberg 7y ago
Technically, you should be able to just call exit(1) because of the C's support for "implicit function declarations". With no prior exit() declaration, the C compiler would assume that "exit" is "int exit()", spit out the code to push whatever arguments are passed to it down the stack and then just call the damn thing. So, magically, it will all just work. Requires an older compiler though, C89 the latest.
- jart 7y ago
  Modern GCC and Clang still support implicit functions. They just complain about it by default. (Mostly for reasons that shouldn't be entirely relevant to modern x86.)

emilfihlman 7y ago

Why is fputs returning 1?

fit2rule 7y ago
1 is a non-negative number. fputs() return nonnegative numbers on success...
- emilfihlman 7y ago
  Ah yeah true, looked at the wrong part of a man page.

xvilka 7y ago

It lacks the syntax highlight. They could have used tree-sitter[1] for parsing, then the online highlight would be easier to implement. [1] https://github.com/tree-sitter/tree-sitter https://github.com/tree-sitter/tree-sitter

israrkhan 7y ago
perhaps you meant to include https://github.com/tree-sitter/tree-sitter https://github.com/tree-sitter/tree-sitter as reference.
- xvilka 7y ago
  Oh, yes, clipboard mistake, thanks for the correction!
hexagonal-sun 7y ago
Agreed, syntax highlighting would be great. I was thinking about something akin to fish's syntax highlighting and completion with the REPL. I'll take a look at tree-sitter. If I get syntax highlighting for free then I'll take that!
johnisgood 7y ago
> Dependency-free so that the runtime library (which is written in pure C) can be embedded in any application What does dependency-free mean? I mean, it does depend on 128 crates. Do we typically not count those? By the way, I did `cargo build` and it failed at `#include "utf8proc.c"`. I have `libutf8proc` installed. Changing `.c` to `.h` solved it. It went past that part, only to get: - error: couldn't read cli/src/../../lib/binding_web/tree-sitter.js: No such file or directory (os error 2) - error: couldn't read cli/src/../../lib/binding_web/tree-sitter.wasm: No such file or directory (os error 2)
- TkTech 7y ago
  The generator isn't dependency free, the parser it generates is.

israrkhan 7y ago

an integration with jupyter would be nice.

deleted 7y ago

[deleted]

fortran77 7y ago

In the late 80s there was a product called C-Terp, which I loved! Here's a link to a brief description: https://books.google.com/books?id=fHghpJa3va4C&lpg=PA167&ots=Tq9xCXDt76&dq=C-Terp%20c%20interpreter&pg=PA167#v=onepage&q=C-Terp%20c%20interpreter&f=false https://books.google.com/books?id=fHghpJa3va4C&lpg=PA167&ots... And, yes, I paid the $295 for it.

wrp 7y ago

Interactive C environments were popular for a while. I have collected information on several at the Computer History Museum. I actually have even more stuff that I never got around to uploading. You unfortunately need to make an account to see the pages. It was heavily attacked at one time and that was the admin's solution. Interactive C Environments http://www.softwarepreservation.org/projects/interactive_c http://www.softwarepreservation.org/projects/interactive_c

jart 7y ago

One cool trick for C REPLs is to grep the man page directory to automate those pesky #include lines, e.g. https://gist.github.com/jart/5d0934d26b52f38cad36 https://gist.github.com/jart/5d0934d26b52f38cad36 Another trick is to build with STABS and use objdump -g.

forpace 7y ago

One of the biggest problem with these repl for complied languages is that they panic as soon as you rerun a command. `cling` integrates with Jupyter notebook too but as soon as you rerun a declaration of a variable, everything collapse and you have to reset the kernel. Maybe I didn’t dig deep enough and there is a way around this but if not, this is quite painful to deal with and a deal breaker.