New Mraa specific exceptions for errors

src/linuxX64Main/kotlin/com/robgulley/hwint/MraaError.kt

@@ -0,0 +1,40 @@
+package com.robgulley.hwint
+
+import kotlinx.cinterop.toKString
+import mraa.MRAA_SUCCESS
+import mraa.mraa_result_t
+import platform.posix.posix_errno
+import platform.posix.strerror
+
+internal inline fun <T> T.ensurePosixCallResult(op: String, predicate: (T) -> Boolean): T {
+    if (!predicate(this)) {
+        val message = "${posix_errno()} for $op: ${strerror(posix_errno())!!.toKString()}"
+        when {
+            op.contains("i2c", ignoreCase = true) -> throwMraaI2CException(message)
+            op.contains("gpio", ignoreCase = true) -> throwMraaGPIOException(message)
+            op.contains("uart", ignoreCase = true) -> throwMraaUARTException(message)
+            else -> throwMraaException(message)
+        }
+    }
+    return this
+}
+
+internal fun mraa_result_t.ensureSuccess(debugString: String) =
+    this.ensurePosixCallResult(debugString) { it == MRAA_SUCCESS }
+
+class MraaException(override val message: String?) : RuntimeException()
+class MraaI2CException(override val message: String?) : RuntimeException()
+class MraaGPIOException(override val message: String?) : RuntimeException()
+class MraaUARTException(override val message: String?) : RuntimeException()
+
+internal fun throwMraaException(message: String): Nothing =
+    throw MraaException("unknown device or operation: $message")
+
+internal fun throwMraaI2CException(message: String): Nothing =
+    throw MraaI2CException(message)
+
+internal fun throwMraaGPIOException(message: String): Nothing =
+    throw MraaGPIOException(message)
+
+internal fun throwMraaUARTException(message: String): Nothing =
+    throw MraaUARTException(message)