StringBuiltins: remove TruffleBoundary for strip/lstrip/rstrip

Author: cosminbasca

graalpython/com.oracle.graal.python.test/src/tests/test_string.py

@@ -1080,3 +1080,19 @@ def test_strip_whitespace():
     assert 'hello   ' == '   hello   '.lstrip(None)
     assert '   hello' == '   hello   '.rstrip(None)
     assert 'hello' == 'hello'.strip(None)
+
+
+def test_strip_with_sep():
+    # strip/lstrip/rstrip with str arg
+    assert 'hello' == 'xyzzyhelloxyzzy'.strip('xyz')
+    assert 'helloxyzzy' == 'xyzzyhelloxyzzy'.lstrip('xyz')
+    assert 'xyzzyhello' == 'xyzzyhelloxyzzy'.rstrip('xyz')
+    assert 'hello' == 'hello'.strip('xyz')
+    assert '' == 'mississippi'.strip('mississippi')
+
+    # only trim the start and end; does not strip internal characters
+    assert 'mississipp' == 'mississippi'.strip('i')
+
+    assertRaises(TypeError, 'hello', 'strip', 42, 42)
+    assertRaises(TypeError, 'hello', 'lstrip', 42, 42)
+    assertRaises(TypeError, 'hello', 'rstrip', 42, 42)

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/str/StringBuiltins.java

@@ -57,7 +57,6 @@
 import java.nio.charset.CodingErrorAction;
 import java.util.Arrays;
 import java.util.List;
-import java.util.regex.Pattern;
 
 import com.oracle.graal.python.builtins.Builtin;
 import com.oracle.graal.python.builtins.CoreFunctions;
@@ -1359,9 +1358,8 @@ public String doReplace(String self, String old, String with, int maxsplit) {
     @TypeSystemReference(PythonArithmeticTypes.class)
     public abstract static class StripNode extends PythonBuiltinNode {
         @Specialization
-        @TruffleBoundary
         String strip(String self, String chars) {
-            return self.replaceAll("^[" + Pattern.quote(chars) + "]+", "").replaceAll("[" + Pattern.quote(chars) + "]+$", "");
+            return StringUtils.strip(self, chars, StripKind.BOTH);
         }
 
         @SuppressWarnings("unused")
@@ -1376,9 +1374,8 @@ String strip(String self, PNone chars) {
     @TypeSystemReference(PythonArithmeticTypes.class)
     public abstract static class RStripNode extends PythonBuiltinNode {
         @Specialization
-        @TruffleBoundary
         String rstrip(String self, String chars) {
-            return self.replaceAll("[" + Pattern.quote(chars) + "]+$", "");
+            return StringUtils.strip(self, chars, StripKind.RIGHT);
         }
 
         @SuppressWarnings("unused")
@@ -1393,9 +1390,8 @@ String rstrip(String self, PNone chars) {
     @TypeSystemReference(PythonArithmeticTypes.class)
     public abstract static class LStripNode extends PythonBuiltinNode {
         @Specialization
-        @TruffleBoundary
         String rstrip(String self, String chars) {
-            return self.replaceAll("^[" + Pattern.quote(chars) + "]+", "");
+            return StringUtils.strip(self, chars, StripKind.LEFT);
         }
 
         @SuppressWarnings("unused")

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/str/StringUtils.java

@@ -168,4 +168,35 @@ public static String strip(String str, StripKind stripKind) {
 
         return str.substring(i, j);
     }
+
+    public static String strip(String str, String chars, StripKind stripKind) {
+        int i = 0;
+        int len = str.length();
+        // TODO: cpython uses a bloom filter for to skip chars that are not in the sep list:
+        // to avoid the linear search in chars
+        if (stripKind != StripKind.RIGHT) {
+            while (i < len) {
+                char ch = str.charAt(i);
+                if (chars.indexOf(ch) < 0) {
+                    break;
+                }
+                i++;
+            }
+        }
+
+        int j = len;
+        if (stripKind != StripKind.LEFT) {
+            j--;
+            while (j >= i) {
+                char ch = str.charAt(j);
+                if (chars.indexOf(ch) < 0) {
+                    break;
+                }
+                j--;
+            }
+            j++;
+        }
+
+        return str.substring(i, j);
+    }
 }