Support string constants that begin or end with numbers

Author: dkhalanskyjb

core/common/src/internal/format/StringFormat.kt

@@ -134,7 +134,25 @@ internal fun <T> FormatStructure<T>.formatter(): FormatterStructure<T> = when (t
 private fun <T> FormatStructure<T>.parser(): ParserStructure<T> = when (this) {
     is ConstantFormatStructure ->
         ParserStructure(
-            operations = if (string.isNotEmpty()) listOf(PlainStringParserOperation(string)) else emptyList(),
+            operations = when {
+                string.isEmpty() -> emptyList()
+                else -> buildList {
+                    val suffix = if (string[0].isDigit()) {
+                        add(NumberSpanParserOperation(listOf(ConstantNumberConsumer(string.takeWhile { it.isDigit() }))))
+                        string.dropWhile { it.isDigit() }
+                    } else {
+                        string
+                    }
+                    if (suffix.isNotEmpty()) {
+                        if (suffix[suffix.length - 1].isDigit()) {
+                            add(PlainStringParserOperation(suffix.dropLastWhile { it.isDigit() }))
+                            add(NumberSpanParserOperation(listOf(ConstantNumberConsumer(suffix.takeLastWhile { it.isDigit() }))))
+                        } else {
+                            add(PlainStringParserOperation(suffix))
+                        }
+                    }
+                }
+            },
             followedBy = emptyList()
         )
 
@@ -238,4 +256,4 @@ internal class PropertyWithDefault<in T, E> private constructor(private val acce
     }
 
     inline fun isDefaultComparisonPredicate() = ComparisonPredicate(defaultValue, accessor::getter)
-}
+}

core/common/src/internal/format/parser/NumberConsumer.kt

@@ -103,9 +103,9 @@ internal class ConstantNumberConsumer<in Receiver>(
     private val expected: String
 ) : NumberConsumer<Receiver>(expected.length, "the predefined string $expected") {
     override fun consume(storage: Receiver, input: String): NumberConsumptionError? = if (input == expected) {
-        NumberConsumptionError.WrongConstant(expected)
-    } else {
         null
+    } else {
+        NumberConsumptionError.WrongConstant(expected)
     }
 }
 

core/common/test/format/DateTimeFormatTest.kt

@@ -75,4 +75,18 @@ class DateTimeFormatTest {
             }
         """.trimIndent(), kotlinCode)
     }
+
+    @Test
+    fun testParseStringWithNumbers() {
+        val formats = listOf(
+            "0123x0123",
+            "0123x",
+            "x0123",
+            "0123",
+            "x"
+        )
+        for (format in formats) {
+            DateTimeComponents.Format { chars(format) }.parse(format)
+        }
+    }
 }