new posts

posts/_metadata.json

@@ -7,6 +7,22 @@
     "author": "jetstream0/Prussia",
     "tags": ["meta", "code", "project", "web", "markdown", "typescript_javascript", "css"]
   },
+  "llm": {
+    "title": "LLM",
+    "slug": "llm",
+    "filename": "llm",
+    "date": "16/09/2023",
+    "author": "jetstream0/Prussia",
+    "tags": ["opinion"]
+  },
+  "hex-to-bytes-and-back": {
+    "title": "Hex to Bytes and Back",
+    "slug": "hex-to-bytes-and-back",
+    "filename": "hex_to_bytes_and_back",
+    "date": "15/09/2023",
+    "author": "jetstream0/Prussia",
+    "tags": ["typescript_javascript", "code", "math"]
+  },
   "rss-feed": {
     "title": "RSS!",
     "slug": "rss-feed",

posts/hex_to_bytes_and_back.md

@@ -0,0 +1,61 @@
+I've written a lot of Javascript over the past few years. How much? I'm not sure, but 100 thousand lines is probably a good estimate^\[0\]^^\[1\]^. The two functions  that I've written the most, over and over, are no doubt the function to turn hexadecimals to bytes, and vice versa.
+
+Part of this is because I do a lot of stuff related to cryptography and cryptocurrency (which, no surprise, is basically just *more* cryptography), which involves tons of work with bytes and often, converting them to hex for storage or display. The other part is because Javascript doesn't have a builtin way to convert hex to bytes or the other way around (Node.js apparently has `Buffer.from` but I never use that), and also because I just like writing things from scratch, which you may notice is a common theme in this blog. In addition to my trademark unnecessarily long sentences, of course.
+
+## Bytes
+
+I assume you already know what bytes and hexadecimals are, but in case you don't, here's a brief overview.
+
+Bits have two states. Bytes are made out of eight bits, so one byte can have 256 (`2^8=256`) states.
+
+Now, there are a couple ways you can represent bytes. One way could be representing them in binary, with 1s and 0s. Another would be just using our normal decimal (base 10 numbers), where a byte could be represented by a number from 0 to 255. But the best way (in my opinion) is to use hexadecimals (base 16 numbers) which uses the digits 0-9 and A-F. `A` represents 10, `B` represents 11, and so on. `FF` would represent 255 in decimal (`15*16+15=255`), `10` would represent 16 (`1*16+0`), and `32` would represent 50 (`3*16+2=50`).
+
+Why base 16? If you remember, one byte can have 256 states, meaning that two hexadecimal digits can perfectly represent one byte (`16^2=256`) which is a lot more elegant than decimal, and a lot more concise than binary. With decimal, it isn't exactly clear how many bytes 2402655566 is, while it is very clear how many bytes 8F359D4E is (8 hex digits, so 4 bytes).
+
+## Uint8Array
+
+Anyways, back on topic. In Javascript, bytes are often represented by [Uint8Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array), which are shockingly an array of Uint8s. What are Uint8s? Uint means "unsigned integer", or basically a non-negative whole number. The 8 stands for the 8 bits, so a Uint8 is an array of one byte unsigned integers^\[2\]^. Basically, it's a way to represent bytes in Javascript by storing in as an array of decimal numbers from 0-255.
+
+## Converting Bytes to Hexadecimal
+
+```js
+function uint8_to_hex(uint8) {
+  const hex_chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'];
+  let hex = "";
+  for (let i=0; i < uint8.length; i++) {
+    hex += hex_chars[Math.floor(uint8[i]/16)];
+    hex += hex_chars[uint8[i] % 16];
+  }
+  return hex;
+}
+```
+
+The loop iterates through through the `Uint8Array`, first dividing it by 16 and rounding down, to find the first hex character. Then, it divides by 16 and takes the remainder for the second hex character.
+
+## Converting Hexadecimal to Bytes
+
+```js
+function hex_to_uint8(hex) {
+  const hex_chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'];
+  hex = hex.toUpperCase();
+  let uint8 = new Uint8Array(Math.floor(hex.length/2));
+  for (let i=0; i < Math.floor(hex.length/2); i++) {
+    uint8[i] = hex_chars.indexOf(hex[i*2])*16;
+    uint8[i] += hex_chars.indexOf(hex[i*2+1]);
+  }
+  return uint8;
+}
+```
+
+Here, we determine how many whole bytes^\[4\]^ are in the hex string, by diving it by two. We then loop that many times, each time convering the two hex characters into a number by finding the value of the first hex character (`indexOf`), multiplying it by 16, then finding the value of the second of the second hex character, and adding it.
+
+By the way, doing, for example, `new Uint8Array(5)`, will initialize an `Uint8Array` of all 0s, of length 5.
+
+This function, as written, isn't designed to take in invalid input, so make sure to valid any inputs. In fact, I would encourage you to go and write your own conversion functions, instead of copy pasting these examples. You'll (hopefully) understand the concepts much faster that way.
+
+===
+- \[0\]: ±50 thousand lines (estimating skills are not my strong suit).
+- \[1\]: [my 6000 lines of unfinished code in one horrific file](https://github.com/jetstream0/Muskets-and-Bayonets/blob/main/script.js).
+- \[2\]: Signed integers have "signs", ie, they can represent negative numbers.
+- \[3\]: In case you were wondering, I do write the `hex_chars` array out every time... slightly painful, but it's too much work to copy paste it from somewhere
+- \[4\]: Note that the `Math.floor` means that this function only works with an even hex string length, since an odd hex string length would mean there's half of a byte (aka a nybble) being used, which is rare-ish.

posts/llm.md

@@ -0,0 +1,11 @@
+"LLMs can write all your cod-"
+Don't care.
+
+"LLMs can supercharge your produc-"
+Don't care.
+
+"We can force LLMs to return valid JSON by not letting them use invalid tokens!"
+Fine, that's pretty cool.
+
+"If you pay for this subscription..."
+Please leave.

posts/wikipedia_rabbitholes.md

@@ -18,7 +18,7 @@ Here's a very incomplete (and maybe actively updated) list of ones that led to m
 - [Diffie-Hellman key exchange](https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange)
 - [Xi'an Incident](https://en.wikipedia.org/wiki/Xi%27an_Incident), where [Chiang Kai-shek](https://en.wikipedia.org/wiki/Chiang_Kai-shek) (leader of the Nationalists) is kidnapped by his generals [Yang Hucheng](https://en.wikipedia.org/wiki/Yang_Hucheng) and [Chang Hsueh-liang](https://en.wikipedia.org/wiki/Chang_Hsueh-liang), and forced to cooperate with the Communists against the invading Japanese
 - [Abdullah Öcalan](https://en.wikipedia.org/wiki/Abdullah_%C3%96calan), imprisoned [PKK](https://en.wikipedia.org/wiki/Kurdistan_Workers%27_Party) leader
-- [Oda Nobunaga](https://en.wikipedia.org/wiki/Oda_Nobunaga), Japanese warlord, who died because of the [Honnō-ji Incident](https://en.wikipedia.org/wiki/Honn%C5%8D-ji_Incident)
+- [Oda Nobunaga](https://en.wikipedia.org/wiki/Oda_Nobunaga), extremely notable Japanese warlord, who was killed in the [Honnō-ji Incident](https://en.wikipedia.org/wiki/Honn%C5%8D-ji_Incident)
 - [Ishiyama Hongan-ji](https://en.wikipedia.org/wiki/Ishiyama_Hongan-ji), former [Jōdo Shinshū](https://en.wikipedia.org/wiki/J%C5%8Ddo_Shinsh%C5%AB) temple/fortress, was burned down and replaced by [Osaka Castle](https://en.wikipedia.org/wiki/Osaka_Castle), and the reason why the city of [Osaka](https://en.wikipedia.org/wiki/Osaka) exists
 - [Peninsular War](https://en.wikipedia.org/wiki/Peninsular_War), [Napoleon](https://en.wikipedia.org/wiki/Napoleon)'s invasion of Spain and Portugal
 - [Thomas Cochrane, 10th Earl of Dundonald](https://en.wikipedia.org/wiki/Thomas_Cochrane,_10th_Earl_of_Dundonald), successful British Navy officer accused of stock exchange fraud, later participating in [Liberating Expedition of Peru](https://en.wikipedia.org/wiki/Liberating_Expedition_of_Peru) from the Spanish
@@ -85,7 +85,7 @@ Here's a very incomplete (and maybe actively updated) list of ones that led to m
 - [An Lushan Rebellion](https://en.wikipedia.org/wiki/An_Lushan_Rebellion), An Lushan rebels, greatly weakened the Tang Dynasty
 - [Bahmani Sultanate](https://en.wikipedia.org/wiki/Bahmani_Sultanate), South Indian empire
 - [Pagan Empire](https://en.wikipedia.org/wiki/Pagan_Kingdom), the first Burmese kingdom
-- [warsaw Uprising](https://en.wikipedia.org/wiki/Warsaw_Uprising)
+- [Warsaw Uprising](https://en.wikipedia.org/wiki/Warsaw_Uprising)
 - [Polish-Lithuanian Commonwealth](https://en.wikipedia.org/wiki/Polish%E2%80%93Lithuanian_Commonwealth)
 - [Atoll](https://en.wikipedia.org/wiki/Atoll)
 - [Chambre introuvable](https://en.wikipedia.org/wiki/Chambre_introuvable), ultra-royalists Chamber of Deputies elected after the Second Bourbon Restoration
@@ -93,3 +93,31 @@ Here's a very incomplete (and maybe actively updated) list of ones that led to m
 - [Battle of Nagashino](https://en.wikipedia.org/wiki/Battle_of_Nagashino), where Takeda Katsuyori learns it is not a good idea to cavalry charge into gunfire
 - [Twenty-Four Generals of Takeda Shingen](https://en.wikipedia.org/wiki/Twenty-Four_Generals_of_Takeda_Shingen), related to the Battle of Nagashino above, but too interesting to leave out
 - [Battle of Bannockburn](https://en.wikipedia.org/wiki/Battle_of_Bannockburn), decisive Scottish victory in the First War of Scottish Independence
+- [Three Gorges](https://en.wikipedia.org/wiki/Three_Gorges), are three gorges, in China
+- [Annexation of Hyderabad](https://en.wikipedia.org/wiki/Annexation_of_Hyderabad)
+- [Emperor Xuanzong of Tang (9th century)](https://en.wikipedia.org/wiki/Emperor_Xuanzong_of_Tang_%289th_century%29)
+- [List of coups and coup attempts](https://en.wikipedia.org/wiki/List_of_coups_and_coup_attempts)
+- [Lazarus Group](https://en.wikipedia.org/wiki/Lazarus_Group), North Korean hackers
+- [Pasquale Paoli](https://en.wikipedia.org/wiki/Pasquale_Paoli), Corsican nationalist admired by Napoleon
+- [Doge (title)](https://en.wikipedia.org/wiki/Doge_%28title%29), like a King, but elected
+- [Frank Serpico](https://en.wikipedia.org/wiki/Frank_Serpico), New York Police Department whistleblower
+- [Inner Mongolia Incident](https://en.wikipedia.org/wiki/Inner_Mongolia_incident), part of the Cultural Revolution
+- [Nationalist Party of Puerto_Rico](https://en.wikipedia.org/wiki/Nationalist_Party_of_Puerto_Rico)
+- [Rotating locomotion in living systems](https://en.wikipedia.org/wiki/Rotating_locomotion_in_living_systems)
+- [Japanese dialects](https://en.wikipedia.org/wiki/Japanese_dialects)
+- [Ihor Kolomoyskyi](https://en.wikipedia.org/wiki/Ihor_Kolomoyskyi), Ukrainian oligarch
+- [Anglophone Crisis](https://en.wikipedia.org/wiki/Anglophone_Crisis), war in Cameroon due to tensions between English speakers and French speakers
+- [Kivu conflict](https://en.wikipedia.org/wiki/Kivu_conflict)
+- [History of Somalia](https://en.wikipedia.org/wiki/History_of_Somalia)
+- [Migration Period](https://en.wikipedia.org/wiki/Migration_Period), which led to the fall of the Western Roman Empire
+- [Hydrofoil](https://en.wikipedia.org/wiki/Hydrofoil)
+- [General Sherman (tree)](https://en.wikipedia.org/wiki/General_Sherman_%28tree%29), very big and very old
+- [Simón Bolívar](https://en.wikipedia.org/wiki/Sim%C3%B3n_Bol%C3%ADvar), South American revolutionary hero
+- [Battle of Dibrivka](https://en.wikipedia.org/wiki/Battle_of_Dibrivka)
+- [Battle of the Teutoburg Forest](https://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest)
+- [Intentional Community](https://en.wikipedia.org/wiki/Intentional_community)
+- [Jellyfish](https://en.wikipedia.org/wiki/Jellyfish) are apparently "the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa"
+- [Sinecure](https://en.wikipedia.org/wiki/Sinecure), get paid to do nothing
+- [Yelü Dashi](https://en.wikipedia.org/wiki/Yel%C3%BC_Dashi), founder of the Western Liao dynasty
+- [List of Unicode characters](https://en.wikipedia.org/wiki/List_of_Unicode_characters)
+- [Operation Cyclone](https://en.m.wikipedia.org/wiki/Operation_Cyclone), where the CIA funds Islamist groups to fight against the communist Afghan government