Add join method in str

integration_tests/test_str_01.py

@@ -45,6 +45,21 @@ def test_str_repeat():
     assert 3*a*3 == "XyzXyzXyzXyzXyzXyzXyzXyzXyz"
     assert a*-1 == ""
 
+def test_str_join():
+    a: str
+    a = ","
+    p:list[str] = ["a","b"]
+    res:str = a.join(p)
+    assert res == "a,b"
+
+def test_str_join2():
+    a: str
+    a = "**"
+    p:list[str] = ["a","b"]
+    res:str = a.join(p)
+    assert res == "a**b"
+
+
 def test_constant_str_subscript():
     assert "abc"[2] == "c"
     assert "abc"[:2] == "ab"
@@ -55,6 +70,7 @@ def check():
     test_str_index()
     test_str_slice()
     test_str_repeat()
+    test_str_join()
     test_constant_str_subscript()
 
 check()

src/lpython/semantics/python_ast_to_asr.cpp

@@ -33,6 +33,8 @@
 #include <lpython/semantics/python_intrinsic_eval.h>
 #include <lpython/parser/parser.h>
 #include <libasr/serialization.h>
+#include <lpython/pickle.cpp>
+
 
 namespace LCompilers::LPython {
 
@@ -1251,7 +1253,6 @@ class CommonVisitor : public AST::BaseVisitor<Struct> {
                 visit_expr_list(pos_args, n_pos_args, kwargs, n_kwargs,
                                 args, rt_subs, func, loc);
             }
-
             if (ASRUtils::get_FunctionType(func)->m_is_restriction) {
                 rt_vec.push_back(s);
             } else if (ASRUtils::is_generic_function(s)) {
@@ -6664,6 +6665,20 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
             arg.loc = loc;
             arg.m_value = s_var;
             fn_args.push_back(al, arg);
+        } else if (attr_name == "join") {
+            if (args.size() != 1) {
+                throw SemanticError("str.join() takes one argument",
+                    loc);
+            }
+            fn_call_name = "_lpython_str_join";
+            ASR::call_arg_t str_var;
+            str_var.loc = loc;
+            str_var.m_value = s_var;
+            ASR::call_arg_t passed_int;
+            passed_int.loc = loc;
+            passed_int.m_value = args[0].m_value;
+            fn_args.push_back(al, str_var);
+            fn_args.push_back(al, passed_int);
         } else if (attr_name == "find") {
             if (args.size() != 1) {
                 throw SemanticError("str.find() takes one argument",

src/lpython/semantics/python_comptime_eval.h

@@ -80,6 +80,7 @@ struct PythonIntrinsicProcedures {
             {"_lpython_str_count", {m_builtin, &not_implemented}},
             {"_lpython_str_lower", {m_builtin, &not_implemented}},
             {"_lpython_str_upper", {m_builtin, &not_implemented}},
+            {"_lpython_str_join", {m_builtin, &not_implemented}},
             {"_lpython_str_find", {m_builtin, &not_implemented}},
             {"_lpython_str_rstrip", {m_builtin, &not_implemented}},
             {"_lpython_str_lstrip", {m_builtin, &not_implemented}},

src/runtime/lpython_builtin.py

@@ -763,6 +763,14 @@ def _lpython_str_upper(x: str) -> str:
             res += i
     return res
 
+@overload
+def _lpython_str_join(s:str, lis:list[str]) -> str:
+    if len(lis) == 0: return ""
+    res:str = lis[0]
+    i:i32
+    for i in range(1, len(lis)):
+        res += s + lis[i]
+    return res
 
 @overload
 def _lpython_str_find(s: str, sub: str) -> i32:

tests/reference/asr-array_01_decl-39cf894.json

@@ -6,7 +6,7 @@
     "outfile": null,
     "outfile_hash": null,
     "stdout": "asr-array_01_decl-39cf894.stdout",
-    "stdout_hash": "960bc68922ceaabf957cbdc2cfc76c1f4a4758856072d6be3ae9ed18",
+    "stdout_hash": "f1338c6f6e5f0d9e55addc9bd28498dde023b5870395fd4e097788d2",
     "stderr": null,
     "stderr_hash": null,
     "returncode": 0