ICU-22124 Adding a tech preview implementation of MessageFormat v2

icu4j/build.xml

@@ -1361,6 +1361,7 @@
             <packageset dir="${icu4j.core.dir}/src">
                 <include name="com/ibm/icu/lang/**"/>
                 <include name="com/ibm/icu/math/**"/>
+                <include name="com/ibm/icu/message2/**"/>
                 <include name="com/ibm/icu/number/**"/>
                 <include name="com/ibm/icu/text/**"/>
                 <include name="com/ibm/icu/util/**"/>
@@ -1396,6 +1397,7 @@
             <packageset dir="${icu4j.core.dir}/src">
                 <include name="com/ibm/icu/lang/**"/>
                 <include name="com/ibm/icu/math/**"/>
+                <include name="com/ibm/icu/message2/**"/>
                 <include name="com/ibm/icu/number/**"/>
                 <include name="com/ibm/icu/text/**"/>
                 <include name="com/ibm/icu/util/**"/>
@@ -1442,6 +1444,7 @@
             <packageset dir="${icu4j.core.dir}/src">
                 <include name="com/ibm/icu/lang/**"/>
                 <include name="com/ibm/icu/math/**"/>
+                <include name="com/ibm/icu/message2/**"/>
                 <include name="com/ibm/icu/number/**"/>
                 <include name="com/ibm/icu/text/**"/>
                 <include name="com/ibm/icu/util/**"/>
@@ -1646,6 +1649,7 @@
             <packageset dir="${icu4j.core.dir}/src">
                 <include name="com/ibm/icu/lang/**"/>
                 <include name="com/ibm/icu/math/**"/>
+                <include name="com/ibm/icu/message2/**"/>
                 <include name="com/ibm/icu/number/**"/>
                 <include name="com/ibm/icu/text/**"/>
                 <include name="com/ibm/icu/util/**"/>
@@ -1668,6 +1672,7 @@
             <packageset dir="${icu4j.core.dir}/src">
                 <include name="com/ibm/icu/lang/**"/>
                 <include name="com/ibm/icu/math/**"/>
+                <include name="com/ibm/icu/message2/**"/>
                 <include name="com/ibm/icu/number/**"/>
                 <include name="com/ibm/icu/text/**"/>
                 <include name="com/ibm/icu/util/**"/>

icu4j/main/classes/core/src/com/ibm/icu/message2/DateTimeFormatterFactory.java

@@ -0,0 +1,107 @@
+// © 2022 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+package com.ibm.icu.message2;
+
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+
+import com.ibm.icu.impl.locale.AsciiUtil;
+import com.ibm.icu.text.DateFormat;
+import com.ibm.icu.text.SimpleDateFormat;
+
+/**
+ * Creates a {@link Formatter} doing formatting of date / time, similar to
+ * <code>{exp, date}</code> and <code>{exp, time}</code> in {@link com.ibm.icu.text.MessageFormat}.
+ */
+class DateTimeFormatterFactory implements FormatterFactory {
+
+    private static int stringToStyle(String option) {
+        switch (AsciiUtil.toUpperString(option)) {
+            case "FULL": return DateFormat.FULL;
+            case "LONG": return DateFormat.LONG;
+            case "MEDIUM": return DateFormat.MEDIUM;
+            case "SHORT": return DateFormat.SHORT;
+            case "": // intentional fall-through
+            case "DEFAULT": return DateFormat.DEFAULT;
+            default: throw new IllegalArgumentException("Invalid datetime style: " + option);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @throws IllegalArgumentException when something goes wrong
+     *         (for example conflicting options, invalid option values, etc.)
+     */
+    @Override
+    public Formatter createFormatter(Locale locale, Map<String, Object> fixedOptions) {
+        DateFormat df;
+
+        // TODO: how to handle conflicts. What if we have both skeleton and style, or pattern?
+        Object opt = fixedOptions.get("skeleton");
+        if (opt != null) {
+            String skeleton = Objects.toString(opt);
+            df = DateFormat.getInstanceForSkeleton(skeleton, locale);
+            return new DateTimeFormatter(df);
+        }
+
+        opt = fixedOptions.get("pattern");
+        if (opt != null) {
+            String pattern = Objects.toString(opt);
+            SimpleDateFormat sf = new SimpleDateFormat(pattern, locale);
+            return new DateTimeFormatter(sf);
+        }
+
+        int dateStyle = DateFormat.NONE;
+        opt = fixedOptions.get("datestyle");
+        if (opt != null) {
+            dateStyle = stringToStyle(Objects.toString(opt, ""));
+        }
+
+        int timeStyle = DateFormat.NONE;
+        opt = fixedOptions.get("timestyle");
+        if (opt != null) {
+            timeStyle = stringToStyle(Objects.toString(opt, ""));
+        }
+
+        if (dateStyle == DateFormat.NONE && timeStyle == DateFormat.NONE) {
+            // Match the MessageFormat behavior
+            dateStyle = DateFormat.SHORT;
+            timeStyle = DateFormat.SHORT;
+        }
+        df = DateFormat.getDateTimeInstance(dateStyle, timeStyle, locale);
+
+        return new DateTimeFormatter(df);
+    }
+
+    private static class DateTimeFormatter implements Formatter {
+        private final DateFormat icuFormatter;
+
+        private DateTimeFormatter(DateFormat df) {
+            this.icuFormatter = df;
+        }
+
+        /**
+         * {@inheritDoc}
+         */
+        @Override
+        public FormattedPlaceholder format(Object toFormat, Map<String, Object> variableOptions) {
+            // TODO: use a special type to indicate function without input argument.
+            if (toFormat == null) {
+                throw new IllegalArgumentException("The date to format can't be null");
+            }
+            String result = icuFormatter.format(toFormat);
+            return new FormattedPlaceholder(toFormat, new PlainStringFormattedValue(result));
+        }
+
+        /**
+         * {@inheritDoc}
+         */
+        @Override
+        public String formatToString(Object toFormat, Map<String, Object> variableOptions) {
+            return format(toFormat, variableOptions).toString();
+        }
+    }
+}

icu4j/main/classes/core/src/com/ibm/icu/message2/FormattedMessage.java

@@ -0,0 +1,120 @@
+// © 2022 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+package com.ibm.icu.message2;
+
+import java.text.AttributedCharacterIterator;
+
+import com.ibm.icu.text.ConstrainedFieldPosition;
+import com.ibm.icu.text.FormattedValue;
+
+/**
+ * Not yet implemented: The result of a message formatting operation.
+ *
+ * <p>This contains information about where the various fields and placeholders
+ * ended up in the final result.</p>
+ * <p>This class allows the result to be exported in several data types,
+ * including a {@link String}, {@link AttributedCharacterIterator}, more (TBD).</p>
+ *
+ * @internal ICU 72 technology preview
+ * @deprecated This API is for ICU internal use only.
+ */
+@Deprecated
+public class FormattedMessage implements FormattedValue {
+
+    /**
+     * Not yet implemented.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    public FormattedMessage() {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public int length() {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public char charAt(int index) {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public CharSequence subSequence(int start, int end) {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public <A extends Appendable> A appendTo(A appendable) {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public boolean nextPosition(ConstrainedFieldPosition cfpos) {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+    /**
+     * Not yet implemented.
+     *
+     * {@inheritDoc}
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public AttributedCharacterIterator toCharacterIterator() {
+        throw new RuntimeException("Not yet implemented.");
+    }
+
+}

icu4j/main/classes/core/src/com/ibm/icu/message2/FormattedPlaceholder.java

@@ -0,0 +1,79 @@
+// © 2022 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+package com.ibm.icu.message2;
+
+import com.ibm.icu.text.FormattedValue;
+
+/**
+ * An immutable, richer formatting result, encapsulating a {@link FormattedValue},
+ * the original value to format, and we are considering adding some more info.
+ * Very preliminary.
+ *
+ * @internal ICU 72 technology preview
+ * @deprecated This API is for ICU internal use only.
+ */
+@Deprecated
+public class FormattedPlaceholder {
+    private final FormattedValue formattedValue;
+    private final Object inputValue;
+
+    /**
+     * Constructor creating the {@code FormattedPlaceholder}.
+     *
+     * @param inputValue the original value to be formatted.
+     * @param formattedValue the result of formatting the placeholder.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    public FormattedPlaceholder(Object inputValue, FormattedValue formattedValue) {
+        if (formattedValue == null) {
+            throw new IllegalAccessError("Should not try to wrap a null formatted value");
+        }
+        this.inputValue = inputValue;
+        this.formattedValue = formattedValue;
+    }
+
+    /**
+     * Retrieve the original input value that was formatted.
+     *
+     * @return the original value to be formatted.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    public Object getInput() {
+        return inputValue;
+    }
+
+    /**
+     * Retrieve the formatted value.
+     *
+     * @return the result of formatting the placeholder.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    public FormattedValue getFormattedValue() {
+        return formattedValue;
+    }
+
+    /**
+     * Returns a string representation of the object.
+     * It can be null, which is unusual, and we plan to change that.
+     *
+     * @return a string representation of the object.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    @Override
+    public String toString() {
+        return formattedValue.toString();
+    }
+}

icu4j/main/classes/core/src/com/ibm/icu/message2/Formatter.java

@@ -0,0 +1,44 @@
+// © 2022 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+package com.ibm.icu.message2;
+
+import java.util.Map;
+
+/**
+ * The interface that must be implemented by all formatters
+ * that can be used from {@link MessageFormatter}.
+ *
+ * @internal ICU 72 technology preview
+ * @deprecated This API is for ICU internal use only.
+ */
+@Deprecated
+public interface Formatter {
+    /**
+     * A method that takes the object to format and returns
+     * the i18n-aware string representation.
+     *
+     * @param toFormat the object to format.
+     * @param variableOptions options that are not know at build time.
+     * @return the formatted string.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    String formatToString(Object toFormat, Map<String, Object> variableOptions);
+
+    /**
+     * A method that takes the object to format and returns
+     * the i18n-aware formatted placeholder.
+     *
+     * @param toFormat the object to format.
+     * @param variableOptions options that are not know at build time.
+     * @return the formatted placeholder.
+     *
+     * @internal ICU 72 technology preview
+     * @deprecated This API is for ICU internal use only.
+     */
+    @Deprecated
+    FormattedPlaceholder format(Object toFormat, Map<String, Object> variableOptions);
+}