Add isspace API in str (#2373)

Author: Agent-Hellboy

integration_tests/test_str_attributes.py

@@ -276,6 +276,17 @@ def is_ascii():
     s = "123 45 6"
     assert s.isascii() == True
 
+
+def is_space():
+    assert "\n".isspace() == True
+    assert "    ".isspace() == True
+    assert "\r".isspace() == True 
+
+    s:str = " "
+    assert s.isspace() == True   
+    s = "a"
+    assert s.isspace() == False
+
 def check():
     capitalize()
     lower()
@@ -290,5 +301,6 @@ def check():
     is_upper()
     is_decimal()
     is_ascii()
+    is_space()
 
 check()

src/libasr/string_utils.cpp

@@ -142,6 +142,7 @@ std::string str_escape_c(const std::string &s) {
             case '\n': o << "\\n"; break;
             case '\r': o << "\\r"; break;
             case '\t': o << "\\t"; break;
+            case '\v': o << "\\v"; break;
             default:
                 if ('\x00' <= *c && *c <= '\x1f') {
                     o << "\\u"

src/lpython/semantics/python_ast_to_asr.cpp

@@ -6651,7 +6651,7 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
             /*
                 String Validation Methods i.e all "is" based functions are handled here
             */
-            std::vector<std::string> validation_methods{"lower", "upper", "decimal", "ascii"};  // Database of validation methods supported
+            std::vector<std::string> validation_methods{"lower", "upper", "decimal", "ascii", "space"};  // Database of validation methods supported
             std::string method_name = attr_name.substr(2);
 
             if(std::find(validation_methods.begin(),validation_methods.end(), method_name) == validation_methods.end()) {
@@ -6919,7 +6919,7 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                 * islower() method is limited to English Alphabets currently
                 * TODO: We can support other characters from Unicode Library
             */
-            std::vector<std::string> validation_methods{"lower", "upper", "decimal", "ascii"};  // Database of validation methods supported
+            std::vector<std::string> validation_methods{"lower", "upper", "decimal", "ascii", "space"};  // Database of validation methods supported
             std::string method_name = attr_name.substr(2);
             if(std::find(validation_methods.begin(),validation_methods.end(), method_name) == validation_methods.end()) {
                 throw SemanticError("String method not implemented: " + attr_name, loc);
@@ -6999,6 +6999,24 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                 tmp = ASR::make_LogicalConstant_t(al, loc, is_ascii,
                         ASRUtils::TYPE(ASR::make_Logical_t(al, loc, 4)));
                 return;
+            } else if (attr_name == "isspace") {
+                /*
+                  * Specification:
+Return true if all characters in the input string are considered whitespace
+characters, as defined by CPython. Return false otherwise. For now we use the
+std::isspace function, but if we later discover that it differs from CPython,
+we will have to use something else.
+                */
+                bool is_space = true;
+                    for (char i : s_var) {
+                        if (!std::isspace(static_cast<unsigned char>(i))) {
+                            is_space = false;
+                            break;
+                        }
+                    }
+                tmp = ASR::make_LogicalConstant_t(al, loc, is_space,
+                        ASRUtils::TYPE(ASR::make_Logical_t(al, loc, 4)));
+                return;
             } else {
                 throw SemanticError("'str' object has no attribute '" + attr_name + "'", loc);
             }

src/lpython/semantics/python_comptime_eval.h

@@ -92,7 +92,8 @@ struct PythonIntrinsicProcedures {
             {"_lpython_str_islower", {m_builtin, &not_implemented}},
             {"_lpython_str_isupper", {m_builtin, &not_implemented}},
             {"_lpython_str_isdecimal", {m_builtin, &not_implemented}},
-            {"_lpython_str_isascii", {m_builtin, &not_implemented}}
+            {"_lpython_str_isascii", {m_builtin, &not_implemented}},
+            {"_lpython_str_isspace", {m_builtin, &not_implemented}}
         };
     }
 

src/runtime/lpython_builtin.py

@@ -858,6 +858,14 @@ def _lpython_str_isascii(s: str) -> bool:
             return False
     return True
 
+def _lpython_str_isspace(s:str) -> bool:
+    ch: str 
+    for ch in s:
+        if ch != ' ' and ch != '\t' and ch != '\n' and ch != '\r' and ch != '\f' and ch != '\v':
+            return False
+    return True
+
+
 def list(s: str) -> list[str]:
     l: list[str] = []
     i: 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": "24b1d1f4774489a87a82c51c4f4a797ca363f7efdb011e42936fc6b9",
+    "stdout_hash": "337d67c221f17230293b36428d0f59e687b3a1d577e9b361298e1257",
     "stderr": null,
     "stderr_hash": null,
     "returncode": 0