Minor Misadventures in Meta-programming

Recently I resumed working through Peter Seibel's Practical Common Lisp Working thorough the section on binary parsing, an all too common misfortune befell me. I got stuck without any clear idea why. Not quite expert in the use of the macroexpand function I did the usual immediate testing of the example code as I typed it in and loaded it. The results were unexpected, rather than the expanded macro form (i.e. a bunch of generate code), the target code executed. Baffled by the results I began the hunt for the offending code, for I was certain that's where the error was. I searched the examples, scrutinized the meaning of each and every function call in my code, performed many experiments where the meta-programming code was just slightly different than the examples, followed odd hunches on a wild goose chase. All to no avail. Then, while staring blankly at the examples in the book and in the documentation I noticed a minor detail, an apostrophe that I hadn't included in my testing. Ah yes! that blasted apostrophe which tells the reader to treat the following s-expression as a list (i.e. data) rather than as code to execute. Here I thought my error was in the code that I wrote but the error was in how I tried to invoke it. That oversight and my bull headed insistence that the error was in the code I wrote, cost me two days worth of spare time effort. A costly lesson, but a lesson that I am not likely to forget soon.

Moonlight

Standing outside on my deck, looking into my back yard I marveled at how bright the moonlight is tonight. After acclimating your eyes a bit you might even be able to read by it. Brought out the camera to snap a couple of pictures.

The first one is a twenty second exposure.



The second one is a thirty second exposure.



The railing on the deck served as the adhoc tripod. Perhaps I should add a real one to my kit.

Blue Marsh Lake

This weekend, we planned to hike, perhaps at the Boyd Big Tree Preserve. The weather and other circumstances didn't cooperate. In the end we went to Blue Marsh Lake, which is not more than half an hour from home by car. The morning was wet and blustery, but by the afternoon it cleared out and eventually warmed up. We, that is Tom, Karl and I, got there by late afternoon.



As you can see, both Tom and Karl were happy to be there.



We found our first sign of wildlife.



We of course had to investigate the lake. We've been there many times before. So it was all familiar ground. None of us could resist throwing stones into the lake.



We weren't alone at the lake. Other people were there sailing on this cool windy day.



So we went on a trail into the woods along the shore.



Our path eventually let us to a hilltop field.



Then it led deeper into some woods filled with tall trees.



We had gone far enough and decided to turn back.



On our way back, someone decided to hide in the field.



From a distance we saw a bird of prey. Perhaps it was vulture.



Just as we were returning to where our car was parked, we came across some rabbits. Tommy couldn't help but chase them.



It was getting late, but the skies above were a treat for the eyes.



On the way home we drove by Ontelaunee Reservoir as the day was ending.



It was good day to be outside, even if we did get out a bit late.

End of Summer

It's the last weekend of the summer, and I was doing chores, clearing out weeds that have grown all through out the garden. As I was changing the oil in my car, couldn't help but notice how wonderful the weather was. The sun was warm. The air was very clear with a slight breeze that hinted at cooler temperatures on the way. For a bit thoughts of the season changing bounced about in my head. Memories of musings on the end of summer from the year before preoccupied my mind as I was cleaning up from my chores. Then I noticed it. A frog, a real live frog in my back yard. There he was sitting on the roof of the mason bee house on the side of the back yard shed.



Of course I called to everyone else in the family to come and have a look. Misce, Karl and Tom all came out and we all ogled the frog. Tom, Karl and I held him and let him jump about and even let him crawl on our arms and legs. Since we are all shutterbugs, we took many photos always hoping for that special one.



The frog was quite patient with all the attention we gave him, allowing Tom to hold him in his hands.



In the end we released him into the taller grass in the back yard. We hoped he was none the worse for wear.



This little serendipitous visit lit up the rest of the afternoon, and took away the drudgery of the chores. Since the camera was already out, Misce caught on camera some other visitors to our backyard. There was the occasional but very colorful Monarch butterfly, like the one we saw a few days ago.



As well as the ever present busy bees.



The day ended with colorful skies much like those a week ago.



It was a most pleasant day, the kind that you savor as much as you can while they last and fondly remember in less pleasant circumstances.

Hiking at Hamburg Resevoir and Watershed

This weekend my son Tommy, my friend Andy and I went hiking on familiar ground at the Hamburg reservoir and watershed. It had been a while since I last went there. The most recent prior occasion had been in January two years ago. Whenever I go, either with friends or alone, the serenity of the surroundings give me peace and relieve, even if just for a little while, whatever troubles me.

About half a mile or a bit more from the parking lot the path skirts the reservoir.



Many a hiker, including Tommy, finds this a spot for a momentary stop and reflection.



Further up on the hill along one of the steep trails there is a spring, and during those times of year when rain is plentiful its flow is ample.



At the top the path levels out and follows the ridge, gently meandering.



Along the ridge, the path comes to a clearing. At times helicopters use this clearing, perhaps for evacuating injured hikers.



Continuing on the path, some trees along the way had already started to turn. Their autumn colors glowing in the mid day sun.



Strangely enough atop the ridge there were a few unexpected spots with small stagnant ponds. Maybe well hidden frogs and other amphibians live there.



As the path gets closer to the end of the ridge, the foliage changes. Ferns abound.



At the end of the path the forest cover gives way and reveals astounding view of the surrounding countryside.




Atop the rocks about a thousand feet above the farms and houses below, the Pinnacle astounds. Whenever here, I tarry as long as I can.




On a fortunate day, raptors and other large birds show themselves and circle lazily on thermals and ridge effect updrafts.



We were all happy when we arrived here, and a bit pleased with ourselves for making the hike. It was well worth the effort. Tommy thought so.



So did my friend Andy.



As did I.



The circling birds were more numerous than other times of year. This is the beginning the seasonal migration along the Appalachian ridge for many raptors and large birds. As usual, the most common were the Turkey Vultures.



A few Red Tailed Hawks flew past.



As well as a couple of birds that none of us, or any others at the Pinnacle, could identify.



As enchanting as the spot is, necessity cut our visit short. Along the way out, there is a cairn, piled high by passing hikers.



We returned on a different path. It is more narrow, rocky and uneven than the one we arrived on.



Further along the path the trees thinned a bit and the forest floor was overgrown with grass.



The day's sights gave all of us much to think about. At times each of us was lost in deep thought, even Tommy.



The ridge along this southern side of the small valley is littered with rocks and in one spot there is even a natural boulder field.



Eventually the winding rocky path leads to another overlook named Pulpit Rock. From here there is another spectacular view of the surrounding country side.



This includes a glacial boulder field,



The small town of Lenhartsville is also visible.



A sharp and discerning eye can even glimpse Kutztown University.



Closer among the rocks, potentially dangerous snakes lounged. No one disturbed them, and they harmed no one.



From here the path was more a road, easy to follow and walk on.



Though tired, we picked up our pace. Tommy's tiredness seemed to melt away as he drew on his last reserves of energy.



Finally at the car, the day's effort finally caught up with Tommy and sleep overtook him.



Andy was overjoyed at the sight of the car, knowing he could finally get off his feet and sit.



I was so thirsty I drank what we had left of the water.



The whole circuit was perhaps eight miles long and took us about six hours complete. We all agreed it was time well spent, and we all look forward to the next time we go.