[asr->python] initial implementation

[khushi-411]

No description provided.

[certik]

We need to add tests for this, we can consider two kinds:

• testing via our reference tests
• testing via CPython

Both would be useful eventually to have. We can start with the first one, and later do the second one.

[certik]

Try this diff:

--- a/src/libasr/codegen/asr_to_python.cpp
+++ b/src/libasr/codegen/asr_to_python.cpp
@@ -252,6 +252,10 @@ public:
         s = r;
     }
 
+    void visit_ExternalSymbol(const ASR::ExternalSymbol_t &x) {
+        visit_symbol(*x.m_external);
+    }
+
     void visit_Print(const ASR::Print_t &x) {
         std::string r;
         r += "print(";

Then a simple program works, the expr2 now gives:

$ lpython --show-python examples/expr2.py
Internal Compiler Error: Unhandled exception
Traceback (most recent call last):
  File "/Users/ondrej/repos/lpython/src/bin/lpython.cpp", line 1845
    return emit_python(arg_file, runtime_library_dir, compiler_options);
  File "/Users/ondrej/repos/lpython/src/bin/lpython.cpp", line 429
    LCompilers::Result<std::string> res = LCompilers::asr_to_lpython(al, *asr, diagnostics, compiler_options, color, indent);
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 338
    v.visit_TranslationUnit(asr);
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 176
    visit_symbol(*item.second);
  File "../libasr/asr.h", line 5060
  File "../libasr/asr.h", line 4774
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 217
    visit_symbol(*item.second);
  File "../libasr/asr.h", line 5060
  File "../libasr/asr.h", line 4778
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 256
    visit_symbol(*x.m_external);
  File "../libasr/asr.h", line 5060
  File "../libasr/asr.h", line 4775
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 205
    visit_body(x, r, true);
  File "/Users/ondrej/repos/lpython/src/libasr/codegen/asr_to_python.cpp", line 120
    visit_stmt(*x.m_body[i]);
  File "../libasr/asr.h", line 5077
  File "../libasr/asr.h", line 4811
  File "../libasr/asr.h", line 5093
LCompilersException: visit_If() not implemented

So just visit_If has to be implemented as well.

[khushi-411]

Hi, @certik! The PR is ready for your review :-)

Here's the output of the generated code:

def test_boolOp():
    a: bool
    b: bool
    a = False
    b = True
    a = a and b
    b = a or True
    a = a or b
    a = a and (b == b)
    a = a and (b != b)
    a = b or b

And here's the original code:

def test_boolOp():
    a: bool
    b: bool
    a = False
    b = True
    a = a and b
    b = a or True
    a = a or b
    a = a and b == b
    a = a and b != b
    a = b or b

I confirmed the generated and original codes are the same for other tests, too.

Thanks!

[khushi-411]

@certik, @Thirumalai-Shaktivel, this PR is ready to be merged. Gentle ping. Thanks!

[Thirumalai-Shaktivel]

We have to specify the datatype of the argument here, right?

Something like:

def f(x: i32):
	pass

[khushi-411]

Yes! I'll work on this in a follow-up PR. I added a TODO remark so that we don't miss it in future.

[Thirumalai-Shaktivel]

Otherwise, Looks great!

[Thirumalai-Shaktivel]

It went unnoticed, expr17.py is not registered in tests.
You can submit a new PR for now.

[khushi-411]

Yay! Thanks for all your informative reviews, @certik & @Thirumalai-Shaktivel!