# This is a line comment. It can span over
# multiple lines
# 1. Imports
use prelude # This is not necessary. The 'prelude'
# module will always be loaded upon startup
use units::stoney # Load a specific module
# 2. Numbers
12345 # integer notation
12_345 # optional decimal separators
0.234 # floating point notation
.234 # without the leading zero
1.234e15 # scientific notation
1.234e+15
1e-9
1.0e-9
0x2A # hexadecimal
0o52 # octal
0b101010 # binary
NaN # Not a number
inf # Infinity
# 3. Simple expressions
3 + (4 - 3) # Addition and subtraction
1920 / 16 * 9 # Multiplication, division
1920 ÷ 16 × 9 # Unicode-style, '·' is also multiplication
2 pi # Whitespace is implicit multiplication
meter per second # 'per' keyword can be used for division
2^3 # Exponentiation
2**3 # Python-style
2³ # Unicode exponents
2^-3 # Negative exponents
mod(17, 4) # Modulo
3 in -> cm # Unit conversion, can also be → or ➞
3 in to cm # Unit conversion with the 'to' keyword
cos(pi/3 + pi) # Call mathematical functions
pi/3 + pi // cos # Same, 'arg // f' is equivalent to 'f(arg)'
# The '//' operator has the lowest precedence
# which makes it very useful for interactive
# terminals (press up-arrow, and add '// f')
# 4. Constants
let n = 4 # Simple numerical constant
let q1 = 2 m/s # Right hand side can be any expression
let q2: Velocity = 2 m/s # With optional type annotation
let q3: Length / Time = 2 m/s # more complex type annotation
# 5. Function definitions
fn foo(z: Scalar) -> Scalar = 2 * z + 3 # A simple function
fn speed(len: Length, dur: Time) -> Velocity = len / dur # Two parameters
fn my_sqrt<T>(q: T^2) -> T = q^(1/2) # A generic function
fn is_non_negative(x: Scalar) -> Bool = x ≥ 0 # Returns a bool
# 6. Dimension definitions
dimension Fame # A new base dimension
dimension Deceleration = Length / Time^2 # A new derived dimension
# 7. Unit definitions
@aliases(quorks) # Optional aliases-decorator
unit quork = 0.35 meter # A new derived unit
@metric_prefixes # Optional decorator to allow 'milliclonk', etc.
@aliases(ck: short) # short aliases can be used with short prefixes (mck)
unit clonk: Time = 0.2 seconds # Optional type annotation
@metric_prefixes
@aliases(wh: short)
unit warhol: Fame # New base unit for the "Fame" dimension
unit thing # New base unit with automatically generated
# base dimension "Thing"
# 8. Conditionals
fn bump(x: Scalar) -> Scalar = # The construct 'if <cond> then <expr> else <expr>'
if x >= 0 && x <= 1 # is an expression, not a statement. It can span
then 1 # multiple lines.
else 0
# 9. Procedures
print(2 kilowarhol) # Print the value of an expression
print("hello world") # Print a message
print("value of pi = {pi}") # String interpolation
print("sqrt(10) = {sqrt(10)}") # Expressions in string interpolation
print("value of π ≈ {π:.3}") # Format specifiers
assert(1 yard < 1 meter) # Assertion
assert_eq(1 ft, 12 in) # Assert that two quantities are equal
assert_eq(1 yd, 1 m, 10 cm) # Assert that two quantities are equal, up to
# the given precision
type(2 m/s) # Print the type of an expression