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1. Hello world

Prerequisite: follow Install, build, and run.

Create a file

Create hello.incn:

def main() -> None:
    println("Hello, Incan!")

Coming from Python?

In Python you usually write print("..."). In Incan you have both:

  • println("..."): prints with a newline (used in most examples)
  • print("..."): prints without a newline

Tip: Incan uses indentation for blocks. The canonical style is 4 spaces per indent level; see the Incan Code Style Guide and run incan fmt to normalize source.

Run it

If you installed to PATH:

incan run hello.incn

If you used the no-install fallback:

./target/release/incan run hello.incn

When to make it a project

A single hello.incn file is the fastest way to try the language. Once you want tests, dependencies, a stable source root, release metadata, or repeatable project commands, create an Incan project. This is easy to do using the incan cli:

mkdir hello_project
cd hello_project
incan init --name hello_project --yes

This creates incan.toml, src/main.incn, tests/test_main.incn, README.md, and .gitignore. The manifest is the project metadata file; it names the project, records the project version, and declares the default entry point under [project.scripts].

incan.toml
[project]
name = "hello_project"
version = "0.1.0"

[project.scripts]
main = "src/main.incn"

Run the project entry point:

incan run

For the full lifecycle workflow, see Project lifecycle.

Try it

  1. Change the message you print.
  2. Print two lines (two calls to println).
  3. Use print("...") once to see the “no newline” behavior.
One possible solution 
def main() -> None:
    print("Hello")
    println(", Incan!")
    println("Second line")

Next

Next chapter: 2. Values, variables, and types.