feat: type aliases (#1334)

Closes #1308

### Summary of Changes

Add type aliases to simplify reuse of complex types:

```
typealias MyType = union<Int, String>
```

docs/api/safeds/data/image/containers/Image.md

@@ -14,7 +14,8 @@ pipeline example {
 
 ??? quote "Stub code in `Image.sdsstub`"
 
-    ```sds linenums="14"
+    ```sds linenums="13"
+    @Experimental
     class Image {
         /**
          * Get the width of the image in pixels.

docs/api/safeds/data/image/containers/ImageList.md

@@ -13,7 +13,8 @@ To create an `ImageList` call one of the following static methods:
 
 ??? quote "Stub code in `ImageList.sdsstub`"
 
-    ```sds linenums="17"
+    ```sds linenums="16"
+    @Experimental
     class ImageList {
         /**
          * The number of images in this image list.

docs/api/safeds/data/image/typing/ImageSize.md

@@ -13,7 +13,8 @@ A container for image size data.
 
 ??? quote "Stub code in `ImageSize.sdsstub`"
 
-    ```sds linenums="15"
+    ```sds linenums="14"
+    @Experimental
     class ImageSize sub ConstantImageSize
     ```
     { data-search-exclude }

docs/api/safeds/data/labeled/containers/ImageDataset.md

@@ -34,7 +34,8 @@ pipeline example {
 
 ??? quote "Stub code in `ImageDataset.sdsstub`"
 
-    ```sds linenums="25"
+    ```sds linenums="24"
+    @Experimental
     class ImageDataset<out O>(
         @PythonName("input_data") inputData: ImageList,
         @PythonName("output_data") outputData: O,

docs/api/safeds/data/labeled/containers/TimeSeriesDataset.md

@@ -34,7 +34,8 @@ pipeline example {
 
 ??? quote "Stub code in `TimeSeriesDataset.sdsstub`"
 
-    ```sds linenums="29"
+    ```sds linenums="28"
+    @Experimental
     class TimeSeriesDataset(
         data: union<Map<String, List<Any>>, Table>,
         @PythonName("target_name") targetName: String,

docs/api/safeds/data/tabular/containers/Column.md

@@ -9,7 +9,7 @@ A named, one-dimensional collection of homogeneous values.
 | Name | Type | Description | Default |
 |------|------|-------------|---------|
 | `name` | [`String`][safeds.lang.String] | The name of the column. | - |
-| `data` | [`List<T>`][safeds.lang.List] | The data of the column. | `#!sds []` |
+| `data` | [`List<T>`][safeds.lang.List] | The data of the column. | - |
 
 **Type parameters:**
 
@@ -27,10 +27,11 @@ pipeline example {
 
 ??? quote "Stub code in `Column.sdsstub`"
 
-    ```sds linenums="19"
+    ```sds linenums="18"
+    @Category(DataScienceCategory.BasicElement)
     class Column<out T = Any?>(
         name: String,
-        data: List<T> = []
+        data: List<T>,
     ) {
         /**
          * Whether the column is numeric.

docs/api/safeds/data/tabular/containers/StringCell.md

@@ -154,7 +154,7 @@ pipeline example {
          * @example
          * pipeline example {
          *     val column = Column("example", ["abc", "def", "ghi"]);
-         *     val result = column.transform((cell) -> cell.str.substring(1, 2));
+         *     val result = column.transform((cell) -> cell.str.substring(start = 1, length = 2));
          *     // Column("example", ["bc", "ef", "hi"])
          * }
          */
@@ -559,7 +559,7 @@ Get a substring of the string value in the cell.
 ```sds hl_lines="3"
 pipeline example {
     val column = Column("example", ["abc", "def", "ghi"]);
-    val result = column.transform((cell) -> cell.str.substring(1, 2));
+    val result = column.transform((cell) -> cell.str.substring(start = 1, length = 2));
     // Column("example", ["bc", "ef", "hi"])
 }
 ```

docs/api/safeds/data/tabular/containers/Table.md

@@ -18,7 +18,7 @@ To create a `Table` call the constructor or use one of the following static meth
 
 | Name | Type | Description | Default |
 |------|------|-------------|---------|
-| `data` | [`Map<String, List<Any?>>?`][safeds.lang.Map] | The data of the table. If null, an empty table is created. | `#!sds null` |
+| `data` | [`Map<String, List<Any?>>`][safeds.lang.Map] | The data of the table. If null, an empty table is created. | - |
 
 **Examples:**
 
@@ -30,9 +30,10 @@ pipeline example {
 
 ??? quote "Stub code in `Table.sdsstub`"
 
-    ```sds linenums="33"
+    ```sds linenums="32"
+    @Category(DataScienceCategory.BasicElement)
     class Table(
-        data: Map<String, List<Any?>>? = null
+        data: Map<String, List<Any?>>
     ) {
         /**
          * The names of the columns in the table.

docs/api/safeds/data/tabular/containers/TemporalCell.md

@@ -24,7 +24,8 @@ pipeline example {
 
 ??? quote "Stub code in `TemporalCell.sdsstub`"
 
-    ```sds linenums="17"
+    ```sds linenums="16"
+    @Experimental
     class TemporalCell {
         /**
          * Get the century of the underlying date(time) data.

docs/api/safeds/data/tabular/plotting/ColumnPlotter.md

@@ -21,7 +21,8 @@ pipeline example {
 
 ??? quote "Stub code in `ColumnPlotter.sdsstub`"
 
-    ```sds linenums="17"
+    ```sds linenums="16"
+    @Category(DataScienceCategory.BasicElement)
     class ColumnPlotter(
         column: Column<Any>
     ) {

docs/api/safeds/data/tabular/plotting/TablePlotter.md

@@ -21,7 +21,8 @@ pipeline example {
 
 ??? quote "Stub code in `TablePlotter.sdsstub`"
 
-    ```sds linenums="18"
+    ```sds linenums="17"
+    @Category(DataScienceCategory.BasicElement)
     class TablePlotter(
         table: Table
     ) {

docs/api/safeds/data/tabular/transformation/Discretizer.md

@@ -18,7 +18,7 @@ The Discretizer bins continuous data into intervals.
 ```sds hl_lines="3"
 pipeline example {
     val table = Table({"a": [1, 2, 3, 4]});
-    val discretizer = Discretizer(2, columnNames = "a").fit(table);
+    val discretizer = Discretizer(binCount = 2, columnNames = "a").fit(table);
     val transformedTable = discretizer.transform(table);
     // Table({"a": [0, 0, 1, 1]})
 }

docs/api/safeds/lang/AnnotationTarget.md

@@ -64,6 +64,11 @@ The declaration types that can be targeted by annotations.
          */
         Segment
 
+        /**
+         * The annotation can be called on type aliases.
+         */
+        TypeAlias
+
         /**
          * The annotation can be called on type parameters.
          */
@@ -116,6 +121,10 @@ The annotation can be called on results.
 
 The annotation can be called on segments.
 
+## <code class="doc-symbol doc-symbol-variant"></code> `TypeAlias` {#safeds.lang.AnnotationTarget.TypeAlias data-toc-label='[variant] TypeAlias'}
+
+The annotation can be called on type aliases.
+
 ## <code class="doc-symbol doc-symbol-variant"></code> `TypeParameter` {#safeds.lang.AnnotationTarget.TypeParameter data-toc-label='[variant] TypeParameter'}
 
 The annotation can be called on type parameters.

docs/api/safeds/lang/Category.md

@@ -19,7 +19,14 @@ The category of a declaration. It can be used for grouping.
 
 ??? quote "Stub code in `ideIntegration.sdsstub`"
 
-    ```sds linenums="20"
+    ```sds linenums="13"
+    @Experimental
+    @Targets([
+        AnnotationTarget.Class,
+        AnnotationTarget.Enum,
+        AnnotationTarget.Function,
+        AnnotationTarget.Segment,
+    ])
     annotation Category(category: DataScienceCategory)
     ```
     { data-search-exclude }

docs/api/safeds/lang/DataScienceCategory.md

@@ -7,7 +7,8 @@ The letter "Q" is used as a separator for subcategories.
 
 ??? quote "Stub code in `ideIntegration.sdsstub`"
 
-    ```sds linenums="27"
+    ```sds linenums="26"
+    @Experimental
     enum DataScienceCategory {
         /**
          * Basic building blocks.

docs/api/safeds/lang/Deprecated.md

@@ -27,7 +27,18 @@ The declaration should no longer be used.
 
 ??? quote "Stub code in `maturity.sdsstub`"
 
-    ```sds linenums="22"
+    ```sds linenums="11"
+    @Targets([
+        AnnotationTarget.Annotation,
+        AnnotationTarget.Attribute,
+        AnnotationTarget.Class,
+        AnnotationTarget.Enum,
+        AnnotationTarget.EnumVariant,
+        AnnotationTarget.Function,
+        AnnotationTarget.Parameter,
+        AnnotationTarget.Result,
+        AnnotationTarget.Segment,
+    ])
     annotation Deprecated(
         alternative: String? = null,
         reason: String? = null,

docs/api/safeds/lang/Experimental.md

@@ -18,7 +18,18 @@ The declaration might change without a major version bump.
 
 ??? quote "Stub code in `maturity.sdsstub`"
 
-    ```sds linenums="43"
+    ```sds linenums="32"
+    @Targets([
+        AnnotationTarget.Annotation,
+        AnnotationTarget.Attribute,
+        AnnotationTarget.Class,
+        AnnotationTarget.Enum,
+        AnnotationTarget.EnumVariant,
+        AnnotationTarget.Function,
+        AnnotationTarget.Parameter,
+        AnnotationTarget.Result,
+        AnnotationTarget.Segment,
+    ])
     annotation Experimental
     ```
     { data-search-exclude }

docs/api/safeds/lang/Expert.md

@@ -10,7 +10,9 @@ This parameter should only be used by expert users.
 
 ??? quote "Stub code in `ideIntegration.sdsstub`"
 
-    ```sds linenums="8"
+    ```sds linenums="6"
+    @Experimental
+    @Targets([AnnotationTarget.Parameter])
     annotation Expert
     ```
     { data-search-exclude }

docs/api/safeds/lang/Impure.md

@@ -16,7 +16,9 @@ The function has side effects and/or does not always return the same results giv
 
 ??? quote "Stub code in `purity.sdsstub`"
 
-    ```sds linenums="23"
+    ```sds linenums="21"
+    @Experimental
+    @Targets([AnnotationTarget.Function])
     annotation Impure(allReasons: List<ImpurityReason>)
     ```
     { data-search-exclude }

docs/api/safeds/lang/List.md

@@ -38,7 +38,7 @@ pipeline example {
          *
          * @example
          * pipeline example {
-         *     val string = [1, 2, 3].join("-"); // "1-2-3"
+         *     val string = [1, 2, 3].join(separator = "-"); // "1-2-3"
          * }
          */
         @Pure
@@ -53,7 +53,7 @@ pipeline example {
          *
          * @example
          * pipeline example {
-         *     val slice = [1, 2, 3].slice(1, 3); // [2, 3]
+         *     val slice = [1, 2, 3].slice(start = 1, end = 3); // [2, 3]
          * }
          */
         @Pure
@@ -100,7 +100,7 @@ pipeline example {
 ```
 ```sds hl_lines="2"
 pipeline example {
-    val string = [1, 2, 3].join("-"); // "1-2-3"
+    val string = [1, 2, 3].join(separator = "-"); // "1-2-3"
 }
 ```
 
@@ -161,7 +161,7 @@ Return the slice of the list starting at the start index up to but excluding the
 
 ```sds hl_lines="2"
 pipeline example {
-    val slice = [1, 2, 3].slice(1, 3); // [2, 3]
+    val slice = [1, 2, 3].slice(start = 1, end = 3); // [2, 3]
 }
 ```
 

docs/api/safeds/lang/Pure.md

@@ -14,7 +14,9 @@ reordering of calls or parallelization.
 
 ??? quote "Stub code in `purity.sdsstub`"
 
-    ```sds linenums="12"
+    ```sds linenums="10"
+    @Experimental
+    @Targets([AnnotationTarget.Function])
     annotation Pure
     ```
     { data-search-exclude }

docs/api/safeds/lang/PythonMacro.md

@@ -20,7 +20,9 @@ call. `$this` is replaced by the receiver of the call. `$param` is replaced by t
 
 ??? quote "Stub code in `codeGeneration.sdsstub`"
 
-    ```sds linenums="12"
+    ```sds linenums="10"
+    @Experimental
+    @Targets([AnnotationTarget.Function])
     annotation PythonMacro(
         template: String
     )

docs/api/safeds/lang/PythonModule.md

@@ -17,7 +17,8 @@ stubs.
 
 ??? quote "Stub code in `codeGeneration.sdsstub`"
 
-    ```sds linenums="21"
+    ```sds linenums="20"
+    @Targets([AnnotationTarget.Module])
     annotation PythonModule(
         qualifiedName: String
     )

docs/api/safeds/lang/PythonName.md

@@ -23,7 +23,17 @@ The name of the corresponding API element in Python. By default, this is the nam
 
 ??? quote "Stub code in `codeGeneration.sdsstub`"
 
-    ```sds linenums="38"
+    ```sds linenums="28"
+    @Targets([
+        AnnotationTarget.Attribute,
+        AnnotationTarget.Class,
+        AnnotationTarget.Enum,
+        AnnotationTarget.EnumVariant,
+        AnnotationTarget.Function,
+        AnnotationTarget.Parameter,
+        AnnotationTarget.Pipeline,
+        AnnotationTarget.Segment,
+    ])
     annotation PythonName(
         name: String
     )

docs/api/safeds/lang/Repeatable.md

@@ -10,7 +10,8 @@ The annotation can be called multiple times for the same declaration.
 
 ??? quote "Stub code in `annotationUsage.sdsstub`"
 
-    ```sds linenums="83"
+    ```sds linenums="87"
+    @Targets([AnnotationTarget.Annotation])
     annotation Repeatable
     ```
     { data-search-exclude }

docs/api/safeds/lang/String.md

@@ -78,7 +78,7 @@ pipeline example {
          *
          * @example
          * pipeline example {
-         *     val substring = "Hello, world!".substring(7, 12); // "world"
+         *     val substring = "Hello, world!".substring(start = 7, end = 12); // "world"
          * }
          */
         @Pure
@@ -586,7 +586,7 @@ Return the substring of the string starting at the start index up to but excludi
 
 ```sds hl_lines="2"
 pipeline example {
-    val substring = "Hello, world!".substring(7, 12); // "world"
+    val substring = "Hello, world!".substring(start = 7, end = 12); // "world"
 }
 ```
 

docs/api/safeds/lang/Tags.md

@@ -21,7 +21,16 @@ Tags to associate with a declaration. They can be used for filtering.
 
 ??? quote "Stub code in `ideIntegration.sdsstub`"
 
-    ```sds linenums="94"
+    ```sds linenums="85"
+    @Experimental
+    @Targets([
+        AnnotationTarget.Annotation,
+        AnnotationTarget.Class,
+        AnnotationTarget.Enum,
+        AnnotationTarget.Function,
+        AnnotationTarget.Pipeline,
+        AnnotationTarget.Segment,
+    ])
     annotation Tags(tags: List<String>)
     ```
     { data-search-exclude }