Expose Unicode normalization methods on Texts

CHANGELOG.md

@@ -546,6 +546,7 @@
 - [Implemented `replace` on database columns.][7275]
 - [Retire `Column_Selector` and allow regex based selection of columns.][7295]
 - [`Text.parse_to_table` can take a `Regex`.][7297]
+- [Expose `Text.normalize`.][7425]
 
 [debug-shortcuts]:
   https://github.com/enso-org/enso/blob/develop/app/gui/docs/product/shortcuts.md#debug
@@ -778,6 +779,7 @@
 [7275]: https://github.com/enso-org/enso/pull/7275
 [7295]: https://github.com/enso-org/enso/pull/7295
 [7297]: https://github.com/enso-org/enso/pull/7297
+[7425]: https://github.com/enso-org/enso/pull/7425
 
 #### Enso Compiler
 

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Text.enso

@@ -2,6 +2,7 @@ import project.Any.Any
 import project.Data.Locale.Locale
 import project.Data.Numbers.Integer
 import project.Data.Ordering.Ordering
+import project.Data.Text.Normalization.Normalization
 import project.Error.Error
 import project.Errors.Common.Type_Error
 import project.Meta
@@ -142,3 +143,21 @@ type Text
              "14.95€".is_normalized
     is_normalized : Boolean
     is_normalized self = @Builtin_Method "Text.is_normalized"
+
+    ## ALIAS normalise
+
+       Perform Unicode normalization on the string, using the specified method.
+
+       Arguments:
+       - normalization: The `Normalization` method to use.
+
+       > Example
+         Normalize a string.
+
+             'aśb'.normalize == 'as\u0301b'
+    @normalization Normalization.default_widget
+    normalize : Text -> Normalization -> Text
+    normalize self normalization=Normalization.NFD =
+        mode = normalization.get_java_mode
+        name = normalization.get_mode_name
+        Text_Utils.normalizeWithMode self name mode

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Text/Normalization.enso

@@ -0,0 +1,41 @@
+import project.Any.Any
+
+import project.Data.Vector.Vector
+
+polyglot java import com.ibm.icu.text.Normalizer2.Mode
+
+## Enso representations of `com.ibm.icu.text.Normalizer2.Mode`. Does not
+   include all values of `Mode`.
+type Normalization
+    ## Unicode NFC normalization mode.
+    NFC
+
+    ## Unicode NFD normalization mode.
+    NFD
+
+    ## Unicode NFKC normalization mode.
+    NFKC
+
+    ## Unicode NFKD normalization mode.
+    NFKD
+
+    ## Unicode NFKC_CF normalization mode.
+    NFKCCasefold
+
+    ## PRIVATE
+    get_java_mode : Any
+    get_java_mode self = case self of
+        Normalization.NFC -> Mode.COMPOSE
+        Normalization.NFD -> Mode.DECOMPOSE
+        Normalization.NFKC -> Mode.COMPOSE
+        Normalization.NFKD -> Mode.DECOMPOSE
+        Normalization.NFKCCasefold -> Mode.COMPOSE
+
+    ## PRIVATE
+    get_mode_name : Any
+    get_mode_name self = case self of
+        Normalization.NFC -> "nfc"
+        Normalization.NFD -> "nfc"
+        Normalization.NFKC -> "nfkc"
+        Normalization.NFKD -> "nfkc"
+        Normalization.NFKCCasefold -> "nfkc_cf"

distribution/lib/Standard/Base/0.0.0-dev/src/Main.enso

@@ -31,6 +31,7 @@ import project.Data.Text.Encoding.Encoding
 import project.Data.Text.Line_Ending_Style.Line_Ending_Style
 import project.Data.Text.Location.Location
 import project.Data.Text.Matching_Mode.Matching_Mode
+import project.Data.Text.Normalization.Normalization
 import project.Data.Text.Regex.Regex
 import project.Data.Text.Text
 import project.Data.Text.Text_Ordering.Text_Ordering
@@ -118,6 +119,7 @@ export project.Data.Text.Encoding.Encoding
 export project.Data.Text.Line_Ending_Style.Line_Ending_Style
 export project.Data.Text.Location.Location
 export project.Data.Text.Matching_Mode.Matching_Mode
+export project.Data.Text.Normalization.Normalization
 export project.Data.Text.Regex.Regex
 export project.Data.Text.Text
 export project.Data.Text.Text_Ordering.Text_Ordering

std-bits/base/src/main/java/org/enso/base/Text_Utils.java

@@ -5,6 +5,7 @@
 import com.ibm.icu.text.CaseMap.Fold;
 import com.ibm.icu.text.Normalizer;
 import com.ibm.icu.text.Normalizer2;
+import com.ibm.icu.text.Normalizer2.Mode;
 import com.ibm.icu.text.StringSearch;
 import java.util.ArrayList;
 import java.util.List;
@@ -611,6 +612,19 @@ public static String normalize(String str) {
     return Normalizer2.getNFDInstance().normalize(str);
   }
 
+  /**
+   * Normalizes the string to its canonical Unicode form using the specified name and mode.
+   *
+   * @see https://unicode-org.github.io/icu-docs/apidoc/dev/icu4j/com/ibm/icu/text/Normalizer2.html
+   * @see https://unicode-org.github.io/icu-docs/apidoc/dev/icu4j/com/ibm/icu/text/Normalizer2.Mode.html
+   *
+   * @param name the normalization name, must be "nfc", "nfkc", or "nfkc_cf"
+   * @param mode the normalization mode
+   */
+  public static String normalizeWithMode(String str, String name, Mode mode) {
+    return Normalizer2.getInstance(null, name, mode).normalize(str);
+  }
+
   /**
    * Checks if the given string consists only of whitespace characters.
    *

test/Tests/src/Data/Text_Spec.enso

@@ -134,6 +134,23 @@ spec =
             Ordering.compare common_prefix+complex_letter_3+later_suffix  common_prefix+complex_letter_1+earlier_suffix . should_equal Ordering.Greater
             Ordering.compare common_prefix+complex_letter_1+later_suffix  common_prefix+complex_letter_2+earlier_suffix . should_equal Ordering.Greater
 
+        Test.specify "normalizes correctly" <|
+            'aśb'.codepoints . should_equal [97, 347, 98]
+            'as\u0301b'.codepoints . should_equal [97, 115, 769, 98]
+            'aśb'.normalize.codepoints . should_equal [97, 115, 769, 98]
+            'as\u0301b'.normalize.codepoints . should_equal [97, 115, 769, 98]
+
+        Test.specify "normalizes correctly using different standard Unicode normalization modes" <|
+            ## GREEK UPSILON WITH ACUTE AND HOOK SYMBOL behaves differently with each mode.
+               See https://unicode.org/faq/normalization.html
+            s = 'ϓ'
+            s.normalize . codepoints . should_equal [978, 769]
+            s.normalize Normalization.NFC . codepoints . should_equal [979]
+            s.normalize Normalization.NFD . codepoints . should_equal [978, 769]
+            s.normalize Normalization.NFKC . codepoints . should_equal [910]
+            s.normalize Normalization.NFKD . codepoints . should_equal [933, 769]
+            s.normalize Normalization.NFKCCasefold . codepoints . should_equal [973]
+
         Test.specify "should correctly handle case-insensitive equality" <|
             "aBc" . equals_ignore_case "Abc" . should_be_true
             "abc" . equals_ignore_case "abd" . should_be_false