Chris Padilla/Blog
My passion project! Posts spanning music, art, software, books, and more. Equal parts journal, sketchbook, mixtape, dev diary, and commonplace book.
- Setup Type Checking
- Setup a Build Process
- Optionally: Select a TypeScript Runtime
sourcemap
: This generates a.map.js
file which is used for error handling. This makes sane debugging possible even after bundling and minifying.platform=neutral
: Sets default output toesm
, using theexport
syntax.target=es20202
: Targets a specific JS spec, also includingesm
modules.- Request is made to your app with the message "How many Tex-Mex Restaurants are in Dallas?"
- Your application gathers context. For example, we may make a query to our DB for a summary of all restaurants in the area.
- We'll provide a summary of the context and instructions to the LLM with a prompt.
- We send along the response to the user.
How Long Is a Piece of String?
How much time does it really take to get fulfillment out of a creative practice?
I love taking on big projects. It's thrilling to see something grow over time, a song come together note by note, or a drawing take shape stroke by stroke.
There have been times in my life where a project has been all consuming, where my thoughts were on it night and day. Going on the hunt is a thrill of it's own.
When things get busy, though, I have my go-to's for simply keeping my hand in it.
Some days it's just pecking at the piano. Others it's plucking strings. Sometimes it's a sketch over break. 5 minutes here, another 10 there.
I'm grateful for that. When the days fill up with obligation, and I sit down to play a few notes right before bed, that's enough to make the magic happen. I'm continually surprised by how little it takes to tap into something bigger.
James Gurney and Art as an Expression of Nature
A wonderful read in it's entirety on James Gurney's Substack. From "Should Art Be About Personal Expression?":
Many of the greatest works of art have come from enigmatic individuals like Shakespeare, Vermeer, and Homer, about whom we know very little. And perhaps it doesn’t matter. The miracle of their work is that the range of their emotional expression seems to extend beyond the scope of a single person’s experience.
Each of these creators looked into themselves, but in so doing, they saw beyond themselves.
Ultimately, we end up starting from a place where we're trying to express what feels like is uniquely our's. But, the further and further you go, the more you start to see yourself more as a vessel. What pours out of the brush and pen and piano and terminal are alignments with a greater Truth.
Deploying TypeScript to AWS Lambda
In the early days of TypeScript, one of the larger barriers to entry was the setup required. Setting your configuration and checking if external packages ship with types took upfront work. On top of it all, neither Node nor the browser reads TypeScript directly, so transpiling to JavaScript is required for those environments.
Much has improved since. Libraries ship with types and spinning up a project has been streamlined.
Below I'll share some of the tooling that's helped simplify TypeScript setup.
The Project
I'll be working on setting up a TypeScript project that will deploy to AWS Lambda. I'll skip the details that are specific to Lambda setup and focus on TypeScript itself.
For this to work, there are a few things we'll want to make happen:
Type Checking
The biggest benefit of TypeScript comes from... well, the static type checking! An editor such as VS Code can lint these for you while you develop. Though, the intended safeguarding comes from compile time type checking.
TypeScript comes with this out of the box. Here's how you can set it up:
First, we'll install TypeScript globally through npm:
npm install -g typescript
With that comes tsc
, the TypeScript Compiler.
If you haven't already, you'll want to initialize your project with a tsconfig.json
file. This command gets you started:
tsc --init
Here's a starting place for your ts config:
{
"compilerOptions": {
"target": "es2020",
"module": "es2020",
"strict": true,
"skipLibCheck": true,
},
"ts-node": {
"compilerOptions": {
"module": "commonjs"
}
},
"exclude": ["node_modules", "**/*.test.ts"]
}
Lastly, to compile, it's as simple as this command:
tsc index.ts
This will spit out a corrseponding JavaScript file in your project with the types stripped out.
Worth noting: You can also check for types without compiling with the --noEmit
flag.
tsc index.ts --noEmit
Testing Locally
You may notice above the ts-node
option in my config. ts-node is an engine for executing TS files using the node runtime — without having to transpile your code first.
What we would have to do without ts-node
is generate our JS files as we did above, such as with tsc index.ts
. An index.js file would then be generated. From there, we would run node index.js
.
Instead, with ts-node
, we would simply call ts-node index.ts
.
ts-node
comes with many more features, but a single-command way of running TS files from the CLI is the quickest benefit.
Bundling with ESBuild
Typically, we reach for bundling solutions with client side JavaScript and TypeScript to minimize our file sizes, speeding up site load times. While you wouldn't normally need to bundle server side code, the current AWS Lambda limit is 250 MBs. The node_modules
directory would easily eat that up without a bundling strategy!
The library of choice today is ESbuild, which handles TypeScript, JSX, ESM & CommonJS modules, and more.
You might ask: If you're going to bundle your code, why did we bother looking at compiling with tsc
?
There are several tools that will run and build TypeScript without actually validating your types, and ESBuild is one of them! When developing your build pipeline, it's likely that you'll need a separate step to validate the types with tsc
.
Here is what the build script looks like using ESBuild:
esbuild ./src/index.ts --bundle --sourcemap --platform=neutral --target=es2020 --outfile=dist/index.js
A couple of options to explain:
Picking a Runtime
If including esm
modules in your generated JS files, be sure you're using a runtime that supports them. For example, Node 13 can handle them out of the box, while earlier versions require an experimental flag.
When deploying to Lambda, Node is a first class citizen when it comes to support. While not quite as blazingly fast as Rust, a Lambda function running node will still be highly performant.
If you're interested in delightful DX and native TypeScript support however, you may reach for Deno or Bun.
I'll baton pass this portion of the article to two relevant docs: The AWS Lambda Developer Guide on Building with TypeScript and the Bun Lambda Layer package. Whichever you chose, both should be great starting places for deploying your runtime of choice.
Peg O My Heart
Another swing at chord melody!
City Sunset
The Retrieval-Augmented Generation Pattern for AI Development
Yes ladies and gentleman, a post about developing with AI!
If you're team is looking to incorporate an LLM into your services, the first challenge to overcome is how to do so in a cost effective way.
Chances are, your business is already focused on a specific product domain, with resources targeted towards building that solution. This already is going to point you towards finding an off the shelf solution to integrate with an API.
With your flavor of LLM picked, the next set of challenges center around getting it to respond to questions in a way that meaningfully provides answers from your business data. LLM's need to be informed on how to respond to requests, what data to utilize when considering their answers, and even what to do if they're tempted to guess.
The way forward is through prompt engineering, with the help of Retrieval-Augmented Generation
Retrieval-Augmented Generation
The simplified procedure for RAG goes as follows:
That's an overly simplified walk through, but it should already get you thinking about the details involved in those steps depending on your use case.
Another benefit to this is that requests to an API are not inherently stateful. The chat window of an AI app will remember our previous messages. But my API request to that third party does not automatically. We have to store and retrieve that context.
AI Agents
It's worth noting that step 2 may even require an LLM to parse the question and then interact with an API to gather data. There's a fair amount of complexity to still parse in developing these solutions. This is where you may be leaning on an AI Agent. An agent is an LLM that will parse a result and determine if a tool is required, such as pinging your internal APIs.
Prompt Engineering is emerging as a role and craft all of it's own, and there are many nuances to doing it well.
LangChain
The workflow is already so common that there's a framework at the ready to spin up and take care of the heavy lifting for you. LangChain (stylized as 🦜⛓️💥) is just that tool.
For a hands on experience building a RAG application on rails, their docs on building a chatbot are a good starting place.
For a more complex agentive tool, LangGraph opens up the hood on LangChain for more control and plays nicely with LangChain when needed.
Campfire Folk Intro
Gather round, and listen to this tale...
Just a bit of noodling between practicing longer pieces.
Calm Sky
Extending Derived Class Methods in Python
Polymorphism! A sturdy pillar in the foundation of Object Oriented Programming. At it's simplest, it's the ability to change the implementation of specific methods on derived classes.
At face value, that could mean entirely rewriting the method. But what if we want a bit more nuance? What if we want to extend instead of replace the method entirely.
I'll continue on my Vehicle example from my previous post on polymorphism, this time in Python:
from abc import ABC
class Vehicle(ABC):
def __init__(self, color: str):
if not color:
raise ValueError("Color string cannot be null")
self._passengers = []
self.color = color
def load_passenger(self, passenger: str):
# Logic to load passenger
def move(self):
# Some default code for moving
print("Moving 1 mile North")
I've created an Abstract Base Class that serves as a starting point for any derived classes. Within it, I've defined a method move()
that moves the vehicle North by 1 mile. All children will have this class available automatically.
Now, if I want to override that method, it's as simple as declaring a method of the same name in my child classes:
class Car(Vehicle):
def move(self):
print("Driving 1 mile North")
class Boat(Vehicle):
def move(self):
print("Sailing 1 mile North")
In the case that I want to extend the functionality, we can use Super() to do so:
class Car(Vehicle):
def move(self):
super().move()
print("Pedal to metal!")
class Boat(Vehicle):
def move(self):
super().move()
print("Raising the sail!")
The benefit here is I can pass all the same arguments I'm receiving in the method call on either child instance to the default implementation in the parent. They can then be used in my own custom implementation in the child class.
car = Car()
car.move()
# Moving 1 mile North
# Pedal to metal!
Angel Eyes
'Scuse me while I disappear~ 🌫️
Parkway
All the Things You Are Chord Melody
My first swing at chord melody! Love this tune even more on guitar.
Night Lake
The veil is thin. 👻
Squeaked in one Inktober drawing this year! Very much directly inspired by the energetic ink work of Violaine Briat's Lil' Dee.
TypedDicts in Python
So much of JavaScript/TypeScript is massaging data returned from an endpoint through JSON. TypeScript has the lovely ability to type the objects and their properties that come through.
While Python is not as strongly typed as TypeScript, we have this benefit built in to the type hinting system.
It's easier shown than explained:
from typing import Union, TypedDict
from datetime import datetime
class Concert(TypedDict):
"""
Type Dict for concert dictionaries.
"""
id: str
price: int
artist: str
show_time: Union[str, datetime]
All pretty straightforward. We're instantiating a class, inheriting from the TypedDict
base class. Then we set our expected properties as values on that class.
It's ideal to store a class like this in it's own types directory in your project.
A couple of nice ways to use this:
First, you can use this in your methods where you are expecting to receive this dictionary as an argument:
def get_concert_ticket_details(
self, concert: UnitDict = None
) -> tuple(list[str], set[str]):
// Do work
You can also directly create a dictionary from this class through instantiation.
concert = Concert({
"id": "28",
"price": 50,
"artist": "Prince",
"show_time": show_time
})
The benefit of both is, of course, the suggestion in your editor letting you know that a property does not match the expected shape.
More details on Python typing in this previous post. Thorough details available in the official docs.
Sonny Rollins – Oleo
Today I learned that this jazz standard is named after margarine. Yum!