dust/README.md

Dust

High-level programming language with effortless concurrency, automatic memory management and type safety.

Concepts

Dust is heavily influenced by Rust, but aims to be more high-level and easier to use. Its approach to safety is similar in that it will refuse to run programs with issues that can be caught by static analysis. However, Dust is not compiled and while performance is a concern, it is less important than safety and ease of use.

Effortless Concurrency

Rust promises fearless concurrency, and Dust takes it a step further by making concurrency as simple as possible. Dust is organized into statements, and any sequence of statements can be run concurrently by simply adding the async keyword before the block of statements.

# This function will count from 0 to 9, sleeping for an increasing amount of
# time between each number.
count_slowly = fn (
	multiplier: int,
) {
	i = 0

	while i < 10 {
		sleep_time = i * multiplier;

		thread.sleep(sleep_time)
		thread.write_line(i as str)

		i += 1
	}
}

async {
	count_slowly(200) # Finishes last
	count_slowly(100) # Finishes seconds
	count_slowly(50)  # Finishes first
}

Automatic Memory Management

Dust uses a garbage collector to automatically manage memory. During the analysis phase, Dust will determine the number of references to each value. During execution, the intepreter will check the context after each statement and remove values that will not be used again.

x = 0 # x is assigned but never used
      # x is removed from memory

y = 41 # y is assigned
y + 1  # y is kept alive for this statement
       # y is removed from memory

Type Safety

Dust is statically typed and null-free, but the type of a value can usually be inferred from its usage. Dust will refuse to run programs with type errors, but will usually not require type annotations.

# These two statements are identical to Dust
x = 1
x: int = 1

# Numbers with decimals are floats
y = 10.0
y: float = 10.0

# Strings are enclosed in single or double quotes and are guaranteed to be valid UTF-8
z = "Hello, world!"
z: string = "Hello, world!"

Aside from the ubiqutous bool, int, float, and string types, Dust also has list, map, range, structures, enums and functions.