Add support for dict methods with Const (#2567)

* Implement attributes for `Const dict`

* Remove duplicate changes

* Improve checking for `Const` types

* Simplify type checking for `Const dict`.

* Add tests

* Update test

* Update fetching attribute name logic

Co-authored-by: Thirumalai Shaktivel <74826228+Thirumalai-Shaktivel@users.noreply.github.com>

* Update test references

* Update fetching `dict_type`

Co-authored-by: Thirumalai Shaktivel <74826228+Thirumalai-Shaktivel@users.noreply.github.com>

* Formatting changes

* Update test references

* Update error test references

* Tests: Update test references

* Tests: Add runtime tests and update test references

* Remove checks on the absent `Const` node

* Remove call to `get_contained_type()`

* Tests: Add tests and update references

* Style changes

* Tests: Update tests and add to CMakeLists

* Delete tests/reference/asr-test_const_dict-151acad.json

* Delete tests/reference/asr-test_const_dict-151acad.stdout

* Delete tests/reference/asr-test_const_dict-59445d7.json

* Delete tests/reference/asr-test_dict_const-69479e2.json

* Delete tests/reference/asr-test_dict_const-69479e2.stderr

* Delete tests/reference/asr-test_dict_const-69479e2.stdout

* Delete tests/reference/runtime-test_dict_const-62054df.json

* Delete tests/reference/runtime-test_dict_const-62054df.stderr

* Delete tests/reference/asr-test_const_dict-59445d7.stderr

* Tests: Update error references

* Undo formatting changes

* Remove extra newline

---------

Co-authored-by: Thirumalai Shaktivel <74826228+Thirumalai-Shaktivel@users.noreply.github.com>

Author: kmr-srbh

integration_tests/CMakeLists.txt

@@ -562,6 +562,7 @@ RUN(NAME test_tuple_03       LABELS cpython llvm llvm_jit c)
 RUN(NAME test_tuple_04       LABELS cpython llvm llvm_jit c)
 RUN(NAME test_tuple_concat   LABELS cpython llvm llvm_jit)
 RUN(NAME test_tuple_nested   LABELS cpython llvm llvm_jit)
+RUN(NAME test_const_dict     LABELS cpython llvm llvm_jit)
 RUN(NAME test_dict_01        LABELS cpython llvm llvm_jit c)
 RUN(NAME test_dict_02        LABELS cpython llvm llvm_jit c NOFAST)
 RUN(NAME test_dict_03        LABELS cpython llvm llvm_jit NOFAST)

integration_tests/test_const_dict.py

@@ -0,0 +1,24 @@
+from lpython import i32, f64, Const
+
+CONST_DICTIONARY_INTEGR: Const[dict[str, i32]] = {"a": 1, "b": 2, "c": 3}
+
+print(CONST_DICTIONARY_INTEGR.get("a"))
+assert CONST_DICTIONARY_INTEGR.get("a") == 1
+
+print(CONST_DICTIONARY_INTEGR.keys())
+assert len(CONST_DICTIONARY_INTEGR.keys()) == 3
+
+print(CONST_DICTIONARY_INTEGR.values())
+assert len(CONST_DICTIONARY_INTEGR.values()) == 3
+
+CONST_DICTIONARY_FLOAT: Const[dict[str, f64]] = {"a": 1.0, "b": 2.0, "c": 3.0}
+
+print(CONST_DICTIONARY_FLOAT.get("a"))
+assert CONST_DICTIONARY_FLOAT.get("a") == 1.0
+
+print(CONST_DICTIONARY_FLOAT.keys())
+assert len(CONST_DICTIONARY_FLOAT.keys()) == 3
+
+print(CONST_DICTIONARY_FLOAT.values())
+assert len(CONST_DICTIONARY_FLOAT.values()) == 3
+

src/lpython/semantics/python_attribute_eval.h

@@ -395,6 +395,9 @@ struct AttributeHandler {
 
     static ASR::asr_t* eval_dict_pop(ASR::expr_t *s, Allocator &al, const Location &loc,
             Vec<ASR::expr_t*> &args, diag::Diagnostics &diag) {
+        if (ASRUtils::is_const(s)) {
+            throw SemanticError("cannot pop elements from a const dict", loc);
+        }
         if (args.size() != 1) {
             throw SemanticError("'pop' takes only one argument for now", loc);
         }

tests/errors/test_const_dict.py

@@ -0,0 +1,9 @@
+from lpython import i32, f64, dict, Const
+
+
+def test_const_dict():
+    CONST_DICTIONARY: Const[dict[str, i32]] = {"a": 1, "b": 2, "c": 3}
+    print(CONST_DICTIONARY.pop("a"))
+
+
+test_const_dict()

tests/reference/asr-test_const_dict-59445d7.json

@@ -0,0 +1,13 @@
+{
+    "basename": "asr-test_const_dict-59445d7",
+    "cmd": "lpython --show-asr --no-color {infile} -o {outfile}",
+    "infile": "tests/errors/test_const_dict.py",
+    "infile_hash": "51130e98c759eb3cdbd50848e59879e4689d241c7a8674aa06a5b3c7",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": null,
+    "stdout_hash": null,
+    "stderr": "asr-test_const_dict-59445d7.stderr",
+    "stderr_hash": "1d3729d80a7895dd01baaf0905c6cc9ebadd7f7ce623f4ae5970e2b8",
+    "returncode": 2
+}

tests/reference/asr-test_const_dict-59445d7.stderr

@@ -0,0 +1,5 @@
+semantic error: cannot pop elements from a const dict
+ --> tests/errors/test_const_dict.py:6:11
+  |
+6 |     print(CONST_DICTIONARY.pop("a"))
+  |           ^^^^^^^^^^^^^^^^^^^^^^^^^ 

tests/tests.toml

@@ -1109,6 +1109,10 @@ run = true
 filename = "errors/test_dict16.py"
 run = true
 
+[[test]]
+filename = "errors/test_const_dict.py"
+asr = true
+
 [[test]]
 filename = "errors/test_zero_division.py"
 asr = true