📝 Add docstrings to mltheuser/ktor-6711

Docstrings generation was requested by @mltheuser.

* #5238 (comment)

The following files were modified:

* `ktor-http/common/src/io/ktor/http/HttpUrlEncoded.kt`

Author: coderabbitai[bot]

ktor-http/common/src/io/ktor/http/HttpUrlEncoded.kt

@@ -29,53 +29,75 @@ public fun String.parseUrlEncodedParameters(defaultEncoding: Charset = Charsets.
 }
 
 /**
- * Encode form parameters from a list of pairs
- *
- * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.http.formUrlEncode)
- */
-public fun List<Pair<String, String?>>.formUrlEncode(): String = buildString { formUrlEncodeTo(this) }
+     * Form-url-encodes a list of key/value pairs into an application/x-www-form-urlencoded string.
+     *
+     * @param spaceToPlus If `true`, spaces are encoded as `+`; if `false`, spaces are encoded as `%20`. Defaults to `true`.
+     * @return The encoded form string containing joined `key=value` pairs separated by `&`. Values that are `null` are serialized as keys without `=`.
+     */
+public fun List<Pair<String, String?>>.formUrlEncode(spaceToPlus: Boolean = true): String =
+    buildString { formUrlEncodeTo(this, spaceToPlus) }
 
 /**
- * Encode form parameters from a list of pairs to the specified [out] appendable
+ * Write this list of key/value pairs to the given Appendable using application/x-www-form-urlencoded encoding.
  *
- * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.http.formUrlEncodeTo)
+ * Each pair is serialized as `key` or `key=value` and pairs are joined with `&`. A `null` value produces the key without an `=`. Keys and values are percent-encoded; when [spaceToPlus] is `true` space characters are encoded as `+`, otherwise as `%20`.
+ *
+ * @param out Destination appendable that receives the encoded form string.
+ * @param spaceToPlus If `true`, encode space as `+`; if `false`, encode space as `%20`. Defaults to `true`.
  */
-public fun List<Pair<String, String?>>.formUrlEncodeTo(out: Appendable) {
+public fun List<Pair<String, String?>>.formUrlEncodeTo(out: Appendable, spaceToPlus: Boolean = true) {
     joinTo(out, "&") {
-        val key = it.first.encodeURLParameter(spaceToPlus = true)
+        val key = it.first.encodeURLParameter(spaceToPlus = spaceToPlus)
         if (it.second == null) {
             key
         } else {
-            val value = it.second.toString().encodeURLParameterValue()
+            val value = it.second.toString().encodeURLParameter(spaceToPlus = spaceToPlus)
             "$key=$value"
         }
     }
 }
 
 /**
- * Encode form parameters
- *
- * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.http.formUrlEncode)
- */
-public fun Parameters.formUrlEncode(): String = entries()
+     * Encodes parameters into an application/x-www-form-urlencoded string.
+     *
+     * @param spaceToPlus If `true`, space characters are encoded as `+`. If `false`, spaces are encoded as `%20`.
+     * @return The resulting form-encoded string.
+     */
+public fun Parameters.formUrlEncode(spaceToPlus: Boolean = true): String = entries()
     .flatMap { e -> e.value.map { e.key to it } }
-    .formUrlEncode()
+    .formUrlEncode(spaceToPlus)
 
 /**
- * Encode form parameters to the specified [out] appendable
+ * Write these parameters as application/x-www-form-urlencoded into the given appendable.
  *
- * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.http.formUrlEncodeTo)
+ * @param out Destination to which the encoded form string is written.
+ * @param spaceToPlus If `true`, encode space as `+`; if `false`, encode space as `%20`. Defaults to `true`.
  */
-public fun Parameters.formUrlEncodeTo(out: Appendable) {
-    entries().formUrlEncodeTo(out)
+public fun Parameters.formUrlEncodeTo(out: Appendable, spaceToPlus: Boolean = true) {
+    entries().formUrlEncodeTo(out, spaceToPlus)
 }
 
-internal fun ParametersBuilder.formUrlEncodeTo(out: Appendable) {
-    entries().formUrlEncodeTo(out)
+/**
+ * Write this builder's parameters to the given Appendable using application/x-www-form-urlencoded encoding.
+ *
+ * @param out Destination to which the encoded parameter string is written.
+ * @param spaceToPlus If `true`, space characters are encoded as `'+'`; if `false`, spaces are percent-encoded (`"%20"`).
+ */
+internal fun ParametersBuilder.formUrlEncodeTo(out: Appendable, spaceToPlus: Boolean = true) {
+    entries().formUrlEncodeTo(out, spaceToPlus)
 }
 
-internal fun Set<Map.Entry<String, List<String>>>.formUrlEncodeTo(out: Appendable) {
+/**
+ * Writes the set of parameter entries to the provided Appendable as application/x-www-form-urlencoded data.
+ *
+ * Each map entry is expanded into one or more form fields: if the value list is empty a lone key is written;
+ * otherwise one key=value pair is written for each value in the list. Pairs are encoded and joined with `&`.
+ *
+ * @param out Destination Appendable to write the encoded form string to.
+ * @param spaceToPlus When `true`, spaces are encoded as `+`; when `false`, spaces are percent-encoded.
+ */
+internal fun Set<Map.Entry<String, List<String>>>.formUrlEncodeTo(out: Appendable, spaceToPlus: Boolean = true) {
     flatMap { (key, value) ->
         if (value.isEmpty()) listOf(key to null) else value.map { key to it }
-    }.formUrlEncodeTo(out)
-}
+    }.formUrlEncodeTo(out, spaceToPlus)
+}