Julia examples

c.jl

##################
# Calling C code #
##################

# Simple function that wrap a call to libc clock function
clock() = ccall( (:clock, "libc"), Int32, ())

t = clock()

# Do some stuff

println(clock() - t)

example.jl

#################
# Multi-methods #
#################

# Method declaration
# foo is a function taking one argument of any type
function foo(bar)
    println(bar)
end

# Shorter function declaration
baz(x) = println(x)

# Multimethod
# Takes an argument of type Int (Haskelish syntax)
myprint(x::Int) = println("Int")
# Takes an argument of type Matrix (of any type)
myprint(x::Matrix) = println("Matrix")
# Take an argument of type Matrix of Float64
myprint(x::Matrix{Float64}) = println("Matrix of Float64")

myprint(42)         # First one is called
myprint([1 2 3])    # Second one is called
myprint([0.5 0.42]) # Third one is called

overview.jl

##########################
# Variable and iteration #
##########################

# Dynamic type
a = 42          # Int
a = "toto"      # String
a = [1, 2, 3]   # Vector
a = [1 2 3]     # 1x3 Matrix
a = [1:3]       # same 1x3 Matrix

for e in a
    println(test)
end

# Output
# 1
# 2
# 3

template.jl

###################################
# Templating and type constraints #
###################################


function printtype(m)
    println("Any type")
end

# Takes argument of type T, in julia a type
# is an object, so you can print it
function printtype{T}(m::T)
    println(T)
end

# Takes an argument of type T, with the constraint FloatingPoint
function printtype{T <: FloatingPoint}(m::T)
    println("Floating Point")
end

printtype(42)
printtype(0.42)