From e9dd72024cee9805f9d763387d4c848a316a7307 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 17:55:26 +0200 Subject: julia update version number --- julia.html.markdown | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index a30871eb..d55a166b 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -2,17 +2,18 @@ language: Julia contributors: - ["Leah Hanson", "http://leahhanson.us"] - - ["Pranit Bauva", "http://github.com/pranitbauva1997"] - - ["Daniel YC Lin", "http://github.com/dlintw"] + - ["Pranit Bauva", "https://github.com/pranitbauva1997"] + - ["Daniel YC Lin", "https://github.com/dlintw"] + - ["Martijn Visser", "https://github.com/visr"] filename: learnjulia.jl --- Julia is a new homoiconic functional language focused on technical computing. While having the full power of homoiconic macros, first-class functions, and low-level control, Julia is as easy to learn and use as Python. -This is based on Julia 0.6.4 +This is based on Julia 1.0.0 -```ruby +```julia # Single line comments start with a hash (pound) symbol. #= Multiline comments can be written @@ -779,6 +780,6 @@ code_native(circle_area, (Float64,)) ## Further Reading -You can get a lot more detail from [The Julia Manual](http://docs.julialang.org/en/latest/#Manual-1) +You can get a lot more detail from the [Julia Documentation](https://docs.julialang.org/) The best place to get help with Julia is the (very friendly) [Discourse forum](https://discourse.julialang.org/). -- cgit v1.2.3 From cf5cc6b76cb3978818dc98feef86f62b1b406e63 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 18:00:00 +0200 Subject: autoformat with VS code mostly just spaces between arguments --- julia.html.markdown | 140 ++++++++++++++++++++++++++-------------------------- 1 file changed, 70 insertions(+), 70 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index d55a166b..2e4e7c48 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -31,7 +31,7 @@ This is based on Julia 1.0.0 3 # => 3 (Int64) 3.2 # => 3.2 (Float64) 2 + 1im # => 2 + 1im (Complex{Int64}) -2//3 # => 2//3 (Rational{Int64}) +2 // 3 # => 2//3 (Rational{Int64}) # All of the normal infix operators are available. 1 + 1 # => 2 @@ -41,7 +41,7 @@ This is based on Julia 1.0.0 5 / 2 # => 2.5 # dividing an Int by an Int always results in a Float div(5, 2) # => 2 # for a truncated result, use div 5 \ 35 # => 7.0 -2 ^ 2 # => 4 # power, not bitwise xor +2^2 # => 4 # power, not bitwise xor 12 % 10 # => 2 # Enforce precedence with parentheses @@ -83,7 +83,7 @@ false # Strings are created with " try -"This is a string." + "This is a string." catch ; end # Julia has several types of strings, including ASCIIString and UTF8String. @@ -91,19 +91,19 @@ catch ; end # Character literals are written with ' try -'a' + 'a' catch ; end # Some strings can be indexed like an array of characters try -"This is a string"[1] # => 'T' # Julia indexes from 1 + "This is a string"[1] # => 'T' # Julia indexes from 1 catch ; end # However, this is will not work well for UTF8 strings, # so iterating over strings is recommended (map, for loops, etc). # $ can be used for string interpolation: try -"2 + 2 = $(2 + 2)" # => "2 + 2 = 4" + "2 + 2 = $(2 + 2)" # => "2 + 2 = 4" catch ; end # You can put any Julia expression inside the parentheses. @@ -116,7 +116,7 @@ println("I'm Julia. Nice to meet you!") # String can be compared lexicographically "good" > "bye" # => true "good" == "good" # => true -"1 + 2 = 3" == "1 + 2 = $(1+2)" # => true +"1 + 2 = 3" == "1 + 2 = $(1 + 2)" # => true #################################################### ## 2. Variables and Collections @@ -172,17 +172,17 @@ matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] b = Int8[4, 5, 6] # => 3-element Int8 Array: [4, 5, 6] # Add stuff to the end of a list with push! and append! -push!(a,1) # => [1] -push!(a,2) # => [1,2] -push!(a,4) # => [1,2,4] -push!(a,3) # => [1,2,4,3] -append!(a,b) # => [1,2,4,3,4,5,6] +push!(a, 1) # => [1] +push!(a, 2) # => [1,2] +push!(a, 4) # => [1,2,4] +push!(a, 3) # => [1,2,4,3] +append!(a, b) # => [1,2,4,3,4,5,6] # Remove from the end with pop pop!(b) # => 6 and b is now [4,5] # Let's put it back -push!(b,6) # b is now [4,5,6] again. +push!(b, 6) # b is now [4,5,6] again. a[1] # => 1 # remember that Julia indexes from 1, not 0! @@ -192,7 +192,7 @@ a[end] # => 6 # we also have shift and unshift shift!(a) # => 1 and a is now [2,4,3,4,5,6] -unshift!(a,7) # => [7,2,4,3,4,5,6] +unshift!(a, 7) # => [7,2,4,3,4,5,6] # Function names that end in exclamations points indicate that they modify # their argument. @@ -203,7 +203,7 @@ sort!(arr) # => [4,5,6]; arr is now [4,5,6] # Looking out of bounds is a BoundsError try a[0] # => ERROR: BoundsError() in getindex at array.jl:270 - a[end+1] # => ERROR: BoundsError() in getindex at array.jl:270 + a[end + 1] # => ERROR: BoundsError() in getindex at array.jl:270 catch e println(e) end @@ -221,11 +221,11 @@ a[2:end] # => [2, 3, 4, 5] # Remove elements from an array by index with splice! arr = [3,4,5] -splice!(arr,2) # => 4 ; arr is now [3,5] +splice!(arr, 2) # => 4 ; arr is now [3,5] # Concatenate lists with append! b = [1,2,3] -append!(a,b) # Now a is [1, 2, 3, 4, 5, 1, 2, 3] +append!(a, b) # Now a is [1, 2, 3, 4, 5, 1, 2, 3] # Check for existence in a list with in in(1, a) # => true @@ -236,7 +236,7 @@ length(a) # => 8 # Tuples are immutable. tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. tup[1] # => 1 -try: + try: tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) catch e println(e) @@ -265,7 +265,7 @@ e, d = d, e # => (5,4) # d is now 5 and e is now 4 empty_dict = Dict() # => Dict{Any,Any}() # You can create a dictionary using a literal -filled_dict = Dict("one"=> 1, "two"=> 2, "three"=> 3) +filled_dict = Dict("one" => 1, "two" => 2, "three" => 3) # => Dict{ASCIIString,Int64} # Look up values with [] @@ -296,8 +296,8 @@ end # Use the get method to avoid that error by providing a default value # get(dictionary,key,default_value) -get(filled_dict,"one",4) # => 1 -get(filled_dict,"four",4) # => 4 +get(filled_dict, "one", 4) # => 1 +get(filled_dict, "four", 4) # => 4 # Use Sets to represent collections of unordered, unique values empty_set = Set() # => Set{Any}() @@ -305,7 +305,7 @@ empty_set = Set() # => Set{Any}() filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) # Add more values to a set -push!(filled_set,5) # => Set{Int64}(5,4,2,3,1) +push!(filled_set, 5) # => Set{Int64}(5,4,2,3,1) # Check if the values are in the set in(2, filled_set) # => true @@ -315,7 +315,7 @@ in(10, filled_set) # => false other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) intersect(filled_set, other_set) # => Set{Int64}(3,4,5) union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set([1,2,3,4]),Set([2,3,5])) # => Set{Int64}(1,4) +setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set{Int64}(1,4) #################################################### @@ -338,7 +338,7 @@ end # For loops iterate over iterables. # Iterable types include Range, Array, Set, Dict, and AbstractString. -for animal=["dog", "cat", "mouse"] +for animal = ["dog", "cat", "mouse"] println("$animal is a mammal") # You can use $ to interpolate variables or expression into strings end @@ -356,7 +356,7 @@ end # cat is a mammal # mouse is a mammal -for a in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") +for a in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") println("$(a[1]) is a $(a[2])") end # prints: @@ -364,7 +364,7 @@ end # cat is a mammal # mouse is a mammal -for (k,v) in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") +for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") println("$k is a $v") end # prints: @@ -386,9 +386,9 @@ end # Handle exceptions with a try/catch block try - error("help") + error("help") catch e - println("caught it $e") + println("caught it $e") end # => caught it ErrorException("help") @@ -426,7 +426,7 @@ function varargs(args...) end # => varargs (generic function with 1 method) -varargs(1,2,3) # => (1,2,3) +varargs(1, 2, 3) # => (1,2,3) # The ... is called a splat. # We just used it in a function definition. @@ -434,18 +434,18 @@ varargs(1,2,3) # => (1,2,3) # where it will splat an Array or Tuple's contents into the argument list. add([5,6]...) # this is equivalent to add(5,6) -x = (5,6) # => (5,6) +x = (5, 6) # => (5,6) add(x...) # this is equivalent to add(5,6) # You can define functions with optional positional arguments -function defaults(a,b,x=5,y=6) +function defaults(a, b, x=5, y=6) return "$a $b and $x $y" end -defaults('h','g') # => "h g and 5 6" -defaults('h','g','j') # => "h g and j 6" -defaults('h','g','j','k') # => "h g and j k" +defaults('h', 'g') # => "h g and 5 6" +defaults('h', 'g', 'j') # => "h g and j 6" +defaults('h', 'g', 'j', 'k') # => "h g and j k" try defaults('h') # => ERROR: no method defaults(Char,) defaults() # => ERROR: no methods defaults() @@ -454,8 +454,8 @@ catch e end # You can define functions that take keyword arguments -function keyword_args(;k1=4,name2="hello") # note the ; - return Dict("k1"=>k1,"name2"=>name2) +function keyword_args(;k1=4, name2="hello") # note the ; + return Dict("k1" => k1, "name2" => name2) end keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] @@ -508,7 +508,7 @@ map(add_10, [1,2,3]) # => [11, 12, 13] filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # We can use list comprehensions for nicer maps -[add_10(i) for i=[1, 2, 3]] # => [11, 12, 13] +[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] [add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] #################################################### @@ -537,16 +537,16 @@ typeof(DataType) # => DataType # ... # end type Tiger - taillength::Float64 - coatcolor # not including a type annotation is the same as `::Any` + taillength::Float64 + coatcolor # not including a type annotation is the same as `::Any` end # The default constructor's arguments are the properties # of the type, in the order they are listed in the definition -tigger = Tiger(3.5,"orange") # => Tiger(3.5,"orange") +tigger = Tiger(3.5, "orange") # => Tiger(3.5,"orange") # The type doubles as the constructor function for values of that type -sherekhan = typeof(tigger)(5.6,"fire") # => Tiger(5.6,"fire") +sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") # These struct-style types are called concrete types # They can be instantiated, but cannot have subtypes. @@ -588,19 +588,19 @@ supertype(DirectIndexString) # => AbstractString # <: is the subtyping operator type Lion <: Cat # Lion is a subtype of Cat - mane_color - roar::AbstractString + mane_color + roar::AbstractString end # You can define more constructors for your type # Just define a function of the same name as the type # and call an existing constructor to get a value of the correct type -Lion(roar::AbstractString) = Lion("green",roar) +Lion(roar::AbstractString) = Lion("green", roar) # This is an outer constructor because it's outside the type definition type Panther <: Cat # Panther is also a subtype of Cat - eye_color - Panther() = new("green") + eye_color + Panther() = new("green") # Panthers will only have this constructor, and no default constructor. end # Using inner constructors, like Panther does, gives you control @@ -619,30 +619,30 @@ end # Definitions for Lion, Panther, Tiger function meow(animal::Lion) - animal.roar # access type properties using dot notation + animal.roar # access type properties using dot notation end function meow(animal::Panther) - "grrr" + "grrr" end function meow(animal::Tiger) - "rawwwr" + "rawwwr" end # Testing the meow function meow(tigger) # => "rawwr" -meow(Lion("brown","ROAAR")) # => "ROAAR" +meow(Lion("brown", "ROAAR")) # => "ROAAR" meow(Panther()) # => "grrr" # Review the local type hierarchy -issubtype(Tiger,Cat) # => false -issubtype(Lion,Cat) # => true -issubtype(Panther,Cat) # => true +issubtype(Tiger, Cat) # => false +issubtype(Lion, Cat) # => true +issubtype(Panther, Cat) # => true # Defining a function that takes Cats function pet_cat(cat::Cat) - println("The cat says $(meow(cat))") + println("The cat says $(meow(cat))") end pet_cat(Lion("42")) # => prints "The cat says 42" @@ -657,47 +657,47 @@ end # In Julia, all of the argument types contribute to selecting the best method. # Let's define a function with more arguments, so we can see the difference -function fight(t::Tiger,c::Cat) - println("The $(t.coatcolor) tiger wins!") +function fight(t::Tiger, c::Cat) + println("The $(t.coatcolor) tiger wins!") end # => fight (generic function with 1 method) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The orange tiger wins! +fight(tigger, Panther()) # => prints The orange tiger wins! +fight(tigger, Lion("ROAR")) # => prints The orange tiger wins! # Let's change the behavior when the Cat is specifically a Lion -fight(t::Tiger,l::Lion) = println("The $(l.mane_color)-maned lion wins!") +fight(t::Tiger, l::Lion) = println("The $(l.mane_color)-maned lion wins!") # => fight (generic function with 2 methods) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The green-maned lion wins! +fight(tigger, Panther()) # => prints The orange tiger wins! +fight(tigger, Lion("ROAR")) # => prints The green-maned lion wins! # We don't need a Tiger in order to fight -fight(l::Lion,c::Cat) = println("The victorious cat says $(meow(c))") +fight(l::Lion, c::Cat) = println("The victorious cat says $(meow(c))") # => fight (generic function with 3 methods) -fight(Lion("balooga!"),Panther()) # => prints The victorious cat says grrr +fight(Lion("balooga!"), Panther()) # => prints The victorious cat says grrr try - fight(Panther(),Lion("RAWR")) + fight(Panther(), Lion("RAWR")) catch e - println(e) + println(e) # => MethodError(fight, (Panther("green"), Lion("green", "RAWR")), 0x000000000000557b) end # Also let the cat go first -fight(c::Cat,l::Lion) = println("The cat beats the Lion") +fight(c::Cat, l::Lion) = println("The cat beats the Lion") # This warning is because it's unclear which fight will be called in: try - fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The victorious cat says rarrr + fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The victorious cat says rarrr catch e - println(e) + println(e) # => MethodError(fight, (Lion("green", "RAR"), Lion("brown", "rarrr")), 0x000000000000557c) end # The result may be different in other versions of Julia -fight(l::Lion,l2::Lion) = println("The lions come to a tie") -fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The lions come to a tie +fight(l::Lion, l2::Lion) = println("The lions come to a tie") +fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The lions come to a tie # Under the hood -- cgit v1.2.3 From 031d9d75c4d07b9e3c6007c23f7b331a08d32796 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 19:01:13 +0200 Subject: double space before comments not part of official style guide, but i think it more clearly separates code and comment --- julia.html.markdown | 102 ++++++++++++++++++++++++++-------------------------- 1 file changed, 51 insertions(+), 51 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index 2e4e7c48..c92434ff 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -28,33 +28,33 @@ This is based on Julia 1.0.0 # Everything in Julia is an expression. # There are several basic types of numbers. -3 # => 3 (Int64) -3.2 # => 3.2 (Float64) -2 + 1im # => 2 + 1im (Complex{Int64}) -2 // 3 # => 2//3 (Rational{Int64}) +3 # => 3 (Int64) +3.2 # => 3.2 (Float64) +2 + 1im # => 2 + 1im (Complex{Int64}) +2 // 3 # => 2//3 (Rational{Int64}) # All of the normal infix operators are available. -1 + 1 # => 2 -8 - 1 # => 7 -10 * 2 # => 20 -35 / 5 # => 7.0 -5 / 2 # => 2.5 # dividing an Int by an Int always results in a Float -div(5, 2) # => 2 # for a truncated result, use div -5 \ 35 # => 7.0 -2^2 # => 4 # power, not bitwise xor -12 % 10 # => 2 +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7.0 +5 / 2 # => 2.5 # dividing an Int by an Int always results in a Float +div(5, 2) # => 2 # for a truncated result, use div +5 \ 35 # => 7.0 +2^2 # => 4 # power, not bitwise xor +12 % 10 # => 2 # Enforce precedence with parentheses -(1 + 3) * 2 # => 8 +(1 + 3) * 2 # => 8 # Bitwise Operators -~2 # => -3 # bitwise not -3 & 5 # => 1 # bitwise and -2 | 4 # => 6 # bitwise or -xor(2, 4) # => 6 # bitwise xor -2 >>> 1 # => 1 # logical shift right -2 >> 1 # => 1 # arithmetic shift right -2 << 1 # => 4 # logical/arithmetic shift left +~2 # => -3 # bitwise not +3 & 5 # => 1 # bitwise and +2 | 4 # => 6 # bitwise or +xor(2, 4) # => 6 # bitwise xor +2 >>> 1 # => 1 # logical shift right +2 >> 1 # => 1 # arithmetic shift right +2 << 1 # => 4 # logical/arithmetic shift left # You can use the bits function to see the binary representation of a number. bits(12345) @@ -67,19 +67,19 @@ true false # Boolean operators -!true # => false -!false # => true -1 == 1 # => true -2 == 1 # => false -1 != 1 # => false -2 != 1 # => true -1 < 10 # => true -1 > 10 # => false -2 <= 2 # => true -2 >= 2 # => true +!true # => false +!false # => true +1 == 1 # => true +2 == 1 # => false +1 != 1 # => false +2 != 1 # => true +1 < 10 # => true +1 > 10 # => false +2 <= 2 # => true +2 >= 2 # => true # Comparisons can be chained -1 < 2 < 3 # => true -2 < 3 < 2 # => false +1 < 2 < 3 # => true +2 < 3 < 2 # => false # Strings are created with " try @@ -108,7 +108,7 @@ catch ; end # You can put any Julia expression inside the parentheses. # Another way to format strings is the printf macro. -@printf "%d is less than %f" 4.5 5.3 # 4 is less than 5.300000 +@printf "%d is less than %f" 4.5 5.3 # 4 is less than 5.300000 # Printing is easy println("I'm Julia. Nice to meet you!") @@ -123,22 +123,22 @@ println("I'm Julia. Nice to meet you!") #################################################### # You don't declare variables before assigning to them. -some_var = 5 # => 5 -some_var # => 5 +some_var = 5 # => 5 +some_var # => 5 # Accessing a previously unassigned variable is an error try - some_other_var # => ERROR: some_other_var not defined + some_other_var # => ERROR: some_other_var not defined catch e println(e) end # Variable names start with a letter or underscore. # After that, you can use letters, digits, underscores, and exclamation points. -SomeOtherVar123! = 6 # => 6 +SomeOtherVar123! = 6 # => 6 # You can also use certain unicode characters -☃ = 8 # => 8 +☃ = 8 # => 8 # These are especially handy for mathematical notation 2 * π # => 6.283185307179586 @@ -184,7 +184,7 @@ pop!(b) # => 6 and b is now [4,5] # Let's put it back push!(b, 6) # b is now [4,5,6] again. -a[1] # => 1 # remember that Julia indexes from 1, not 0! +a[1] # => 1 # remember that Julia indexes from 1, not 0! # end is a shorthand for the last index. It can be used in any # indexing expression @@ -237,7 +237,7 @@ length(a) # => 8 tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. tup[1] # => 1 try: - tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) + tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) catch e println(e) end @@ -251,11 +251,11 @@ in(2, tup) # => true a, b, c = (1, 2, 3) # => (1,2,3) # a is now 1, b is now 2 and c is now 3 # Tuples are created even if you leave out the parentheses -d, e, f = 4, 5, 6 # => (4,5,6) +d, e, f = 4, 5, 6 # => (4,5,6) # A 1-element tuple is distinct from the value it contains -(1,) == 1 # => false -(1) == 1 # => true +(1,) == 1 # => false +(1) == 1 # => true # Look how easy it is to swap two values e, d = d, e # => (5,4) # d is now 5 and e is now 4 @@ -411,7 +411,7 @@ end add(5, 6) # => 11 after printing out "x is 5 and y is 6" # Compact assignment of functions -f_add(x, y) = x + y # => "f (generic function with 1 method)" +f_add(x, y) = x + y # => "f (generic function with 1 method)" f_add(3, 4) # => 7 # Function can also return multiple values as tuple @@ -538,7 +538,7 @@ typeof(DataType) # => DataType # end type Tiger taillength::Float64 - coatcolor # not including a type annotation is the same as `::Any` + coatcolor # not including a type annotation is the same as `::Any` end # The default constructor's arguments are the properties @@ -553,7 +553,7 @@ sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") # The other kind of types is abstract types. # abstract Name -abstract type Cat end # just a name and point in the type hierarchy +abstract type Cat end # just a name and point in the type hierarchy # Abstract types cannot be instantiated, but can have subtypes. # For example, Number is an abstract type @@ -587,7 +587,7 @@ supertype(String) # => AbstractString supertype(DirectIndexString) # => AbstractString # <: is the subtyping operator -type Lion <: Cat # Lion is a subtype of Cat +type Lion <: Cat # Lion is a subtype of Cat mane_color roar::AbstractString end @@ -598,7 +598,7 @@ end Lion(roar::AbstractString) = Lion("green", roar) # This is an outer constructor because it's outside the type definition -type Panther <: Cat # Panther is also a subtype of Cat +type Panther <: Cat # Panther is also a subtype of Cat eye_color Panther() = new("green") # Panthers will only have this constructor, and no default constructor. @@ -619,7 +619,7 @@ end # Definitions for Lion, Panther, Tiger function meow(animal::Lion) - animal.roar # access type properties using dot notation + animal.roar # access type properties using dot notation end function meow(animal::Panther) @@ -738,7 +738,7 @@ code_native(square_area, (Float64,)) # push RBP # mov RBP, RSP # Source line: 1 - # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) + # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) # pop RBP # ret # -- cgit v1.2.3 From e18bab117b34f34d7909474928f8d0a713b8df15 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 19:05:54 +0200 Subject: replace tabs with 4 spaces --- julia.html.markdown | 120 ++++++++++++++++++++++++++-------------------------- 1 file changed, 60 insertions(+), 60 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index c92434ff..6964c6c6 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -564,12 +564,12 @@ subtypes(Cat) # => 0-element Array{Any,1} # AbstractString, as the name implies, is also an abstract type subtypes(AbstractString) # 6-element Array{Union{DataType, UnionAll},1}: - # Base.SubstitutionString - # Base.Test.GenericString - # DirectIndexString - # RevString - # String - # SubString + # Base.SubstitutionString + # Base.Test.GenericString + # DirectIndexString + # RevString + # String + # SubString # Every type has a super type; use the `supertype` function to get it. typeof(5) # => Int64 @@ -709,39 +709,39 @@ square_area(5) #25 # What happens when we feed square_area an integer? code_native(square_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 # Prologue - # push RBP - # mov RBP, RSP - # Source line: 1 - # movsxd RAX, EDI # Fetch l from memory? - # imul RAX, RAX # Square l and store the result in RAX - # pop RBP # Restore old base pointer - # ret # Result will still be in RAX + # .section __TEXT,__text,regular,pure_instructions + # Filename: none + # Source line: 1 # Prologue + # push RBP + # mov RBP, RSP + # Source line: 1 + # movsxd RAX, EDI # Fetch l from memory? + # imul RAX, RAX # Square l and store the result in RAX + # pop RBP # Restore old base pointer + # ret # Result will still be in RAX code_native(square_area, (Float32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulss XMM0, XMM0, XMM0 # Scalar single precision multiply (AVX) - # pop RBP - # ret + # .section __TEXT,__text,regular,pure_instructions + # Filename: none + # Source line: 1 + # push RBP + # mov RBP, RSP + # Source line: 1 + # vmulss XMM0, XMM0, XMM0 # Scalar single precision multiply (AVX) + # pop RBP + # ret code_native(square_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) - # pop RBP - # ret - # + # .section __TEXT,__text,regular,pure_instructions + # Filename: none + # Source line: 1 + # push RBP + # mov RBP, RSP + # Source line: 1 + # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) + # pop RBP + # ret + # # Note that julia will use floating point instructions if any of the # arguments are floats. # Let's calculate the area of a circle @@ -749,33 +749,33 @@ circle_area(r) = pi * r * r # circle_area (generic function with 1 method) circle_area(5) # 78.53981633974483 code_native(circle_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vcvtsi2sd XMM0, XMM0, EDI # Load integer (r) from memory - # movabs RAX, 4593140240 # Load pi - # vmulsd XMM1, XMM0, QWORD PTR [RAX] # pi * r - # vmulsd XMM0, XMM0, XMM1 # (pi * r) * r - # pop RBP - # ret - # + # .section __TEXT,__text,regular,pure_instructions + # Filename: none + # Source line: 1 + # push RBP + # mov RBP, RSP + # Source line: 1 + # vcvtsi2sd XMM0, XMM0, EDI # Load integer (r) from memory + # movabs RAX, 4593140240 # Load pi + # vmulsd XMM1, XMM0, QWORD PTR [RAX] # pi * r + # vmulsd XMM0, XMM0, XMM1 # (pi * r) * r + # pop RBP + # ret + # code_native(circle_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # movabs RAX, 4593140496 - # Source line: 1 - # vmulsd XMM1, XMM0, QWORD PTR [RAX] - # vmulsd XMM0, XMM1, XMM0 - # pop RBP - # ret - # + # .section __TEXT,__text,regular,pure_instructions + # Filename: none + # Source line: 1 + # push RBP + # mov RBP, RSP + # movabs RAX, 4593140496 + # Source line: 1 + # vmulsd XMM1, XMM0, QWORD PTR [RAX] + # vmulsd XMM0, XMM1, XMM0 + # pop RBP + # ret + # ``` ## Further Reading -- cgit v1.2.3 From 912a51c8ba87cfea5c9eb0c3285636e91e7c0720 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 19:08:01 +0200 Subject: remove some trailing spaces --- julia.html.markdown | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index 6964c6c6..8cbe3d5e 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -566,9 +566,9 @@ subtypes(Cat) # => 0-element Array{Any,1} subtypes(AbstractString) # 6-element Array{Union{DataType, UnionAll},1}: # Base.SubstitutionString # Base.Test.GenericString - # DirectIndexString - # RevString - # String + # DirectIndexString + # RevString + # String # SubString # Every type has a super type; use the `supertype` function to get it. @@ -680,7 +680,7 @@ fight(Lion("balooga!"), Panther()) # => prints The victorious cat says grrr try fight(Panther(), Lion("RAWR")) catch e - println(e) + println(e) # => MethodError(fight, (Panther("green"), Lion("green", "RAWR")), 0x000000000000557b) end -- cgit v1.2.3 From 876e413558f84d195be625b5c94081c7b6cf6192 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 22:19:14 +0200 Subject: fix julia 0.7 deprecation warnings --- julia.html.markdown | 63 +++++++++++++++++++++++++++-------------------------- 1 file changed, 32 insertions(+), 31 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index 8cbe3d5e..30aeefc2 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -56,10 +56,10 @@ xor(2, 4) # => 6 # bitwise xor 2 >> 1 # => 1 # arithmetic shift right 2 << 1 # => 4 # logical/arithmetic shift left -# You can use the bits function to see the binary representation of a number. -bits(12345) +# You can use the bitstring function to see the binary representation of a number. +bitstring(12345) # => "0000000000000000000000000000000000000000000000000011000000111001" -bits(12345.0) +bitstring(12345.0) # => "0100000011001000000111001000000000000000000000000000000000000000" # Boolean values are primitives @@ -107,8 +107,9 @@ try catch ; end # You can put any Julia expression inside the parentheses. -# Another way to format strings is the printf macro. -@printf "%d is less than %f" 4.5 5.3 # 4 is less than 5.300000 +# Another way to format strings is the printf macro from the stdlib Printf. +using Printf +@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000 # Printing is easy println("I'm Julia. Nice to meet you!") @@ -128,7 +129,7 @@ some_var # => 5 # Accessing a previously unassigned variable is an error try - some_other_var # => ERROR: some_other_var not defined + some_other_var # => ERROR: UndefVarError: some_other_var not defined catch e println(e) end @@ -190,9 +191,9 @@ a[1] # => 1 # remember that Julia indexes from 1, not 0! # indexing expression a[end] # => 6 -# we also have shift and unshift -shift!(a) # => 1 and a is now [2,4,3,4,5,6] -unshift!(a, 7) # => [7,2,4,3,4,5,6] +# we also have popfirst! and pushfirst! +popfirst!(a) # => 1 and a is now [2,4,3,4,5,6] +pushfirst!(a, 7) # => [7,2,4,3,4,5,6] # Function names that end in exclamations points indicate that they modify # their argument. @@ -236,7 +237,7 @@ length(a) # => 8 # Tuples are immutable. tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. tup[1] # => 1 - try: +try tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) catch e println(e) @@ -373,10 +374,11 @@ end # mouse is a mammal # While loops loop while a condition is true -x = 0 -while x < 4 - println(x) - x += 1 # Shorthand for x = x + 1 +let x = 0 + while x < 4 + println(x) + x += 1 # Shorthand for x = x + 1 + end end # prints: # 0 @@ -530,13 +532,13 @@ typeof(DataType) # => DataType # Users can define types # They are like records or structs in other languages. -# New types are defined using the `type` keyword. +# New types are defined using the `struct` keyword. -# type Name +# struct Name # field::OptionalType # ... # end -type Tiger +struct Tiger taillength::Float64 coatcolor # not including a type annotation is the same as `::Any` end @@ -556,6 +558,7 @@ sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") abstract type Cat end # just a name and point in the type hierarchy # Abstract types cannot be instantiated, but can have subtypes. +using InteractiveUtils # defines the subtype and supertype function # For example, Number is an abstract type subtypes(Number) # => 2-element Array{Any,1}: # Complex{T<:Real} @@ -563,13 +566,11 @@ subtypes(Number) # => 2-element Array{Any,1}: subtypes(Cat) # => 0-element Array{Any,1} # AbstractString, as the name implies, is also an abstract type -subtypes(AbstractString) # 6-element Array{Union{DataType, UnionAll},1}: - # Base.SubstitutionString - # Base.Test.GenericString - # DirectIndexString - # RevString - # String - # SubString +subtypes(AbstractString) # 4-element Array{Any,1}: + # String + # SubString + # SubstitutionString + # Test.GenericString # Every type has a super type; use the `supertype` function to get it. typeof(5) # => Int64 @@ -584,10 +585,10 @@ supertype(Any) # => Any typeof("fire") # => String supertype(String) # => AbstractString # Likewise here with String -supertype(DirectIndexString) # => AbstractString +supertype(SubString) # => AbstractString # <: is the subtyping operator -type Lion <: Cat # Lion is a subtype of Cat +struct Lion <: Cat # Lion is a subtype of Cat mane_color roar::AbstractString end @@ -598,10 +599,10 @@ end Lion(roar::AbstractString) = Lion("green", roar) # This is an outer constructor because it's outside the type definition -type Panther <: Cat # Panther is also a subtype of Cat +struct Panther <: Cat # Panther is also a subtype of Cat eye_color Panther() = new("green") - # Panthers will only have this constructor, and no default constructor. + # Panthers will only have this constructor, and no default constructor. end # Using inner constructors, like Panther does, gives you control # over how values of the type can be created. @@ -636,9 +637,9 @@ meow(Lion("brown", "ROAAR")) # => "ROAAR" meow(Panther()) # => "grrr" # Review the local type hierarchy -issubtype(Tiger, Cat) # => false -issubtype(Lion, Cat) # => true -issubtype(Panther, Cat) # => true +Tiger <: Cat # => false +Lion <: Cat # => true +Panther <: Cat # => true # Defining a function that takes Cats function pet_cat(cat::Cat) -- cgit v1.2.3 From 10f50ca2297571a471be4963d1af1a11919627fb Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 22:20:25 +0200 Subject: no need for credit --- julia.html.markdown | 1 - 1 file changed, 1 deletion(-) diff --git a/julia.html.markdown b/julia.html.markdown index 30aeefc2..a71870be 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -4,7 +4,6 @@ contributors: - ["Leah Hanson", "http://leahhanson.us"] - ["Pranit Bauva", "https://github.com/pranitbauva1997"] - ["Daniel YC Lin", "https://github.com/dlintw"] - - ["Martijn Visser", "https://github.com/visr"] filename: learnjulia.jl --- -- cgit v1.2.3 From c8ad0d08093d692dc2d2d5edb1133f6c90318f42 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Tue, 14 Aug 2018 22:30:51 +0200 Subject: more comment spacing --- julia.html.markdown | 212 ++++++++++++++++++++++++++-------------------------- 1 file changed, 106 insertions(+), 106 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index a71870be..e5706062 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -33,27 +33,27 @@ This is based on Julia 1.0.0 2 // 3 # => 2//3 (Rational{Int64}) # All of the normal infix operators are available. -1 + 1 # => 2 -8 - 1 # => 7 -10 * 2 # => 20 -35 / 5 # => 7.0 -5 / 2 # => 2.5 # dividing an Int by an Int always results in a Float -div(5, 2) # => 2 # for a truncated result, use div -5 \ 35 # => 7.0 -2^2 # => 4 # power, not bitwise xor -12 % 10 # => 2 +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7.0 +5 / 2 # => 2.5 # dividing integers always results in a Float64 +div(5, 2) # => 2 # for a truncated result, use div +5 \ 35 # => 7.0 +2^2 # => 4 # power, not bitwise xor +12 % 10 # => 2 # Enforce precedence with parentheses (1 + 3) * 2 # => 8 # Bitwise Operators -~2 # => -3 # bitwise not -3 & 5 # => 1 # bitwise and -2 | 4 # => 6 # bitwise or -xor(2, 4) # => 6 # bitwise xor -2 >>> 1 # => 1 # logical shift right -2 >> 1 # => 1 # arithmetic shift right -2 << 1 # => 4 # logical/arithmetic shift left +~2 # => -3 # bitwise not +3 & 5 # => 1 # bitwise and +2 | 4 # => 6 # bitwise or +xor(2, 4) # => 6 # bitwise xor +2 >>> 1 # => 1 # logical shift right +2 >> 1 # => 1 # arithmetic shift right +2 << 1 # => 4 # logical/arithmetic shift left # You can use the bitstring function to see the binary representation of a number. bitstring(12345) @@ -66,7 +66,7 @@ true false # Boolean operators -!true # => false +!true # => false !false # => true 1 == 1 # => true 2 == 1 # => false @@ -172,17 +172,17 @@ matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] b = Int8[4, 5, 6] # => 3-element Int8 Array: [4, 5, 6] # Add stuff to the end of a list with push! and append! -push!(a, 1) # => [1] -push!(a, 2) # => [1,2] -push!(a, 4) # => [1,2,4] -push!(a, 3) # => [1,2,4,3] -append!(a, b) # => [1,2,4,3,4,5,6] +push!(a, 1) # => [1] +push!(a, 2) # => [1,2] +push!(a, 4) # => [1,2,4] +push!(a, 3) # => [1,2,4,3] +append!(a, b) # => [1,2,4,3,4,5,6] # Remove from the end with pop -pop!(b) # => 6 and b is now [4,5] +pop!(b) # => 6 and b is now [4,5] # Let's put it back -push!(b, 6) # b is now [4,5,6] again. +push!(b, 6) # b is now [4,5,6] again. a[1] # => 1 # remember that Julia indexes from 1, not 0! @@ -191,14 +191,14 @@ a[1] # => 1 # remember that Julia indexes from 1, not 0! a[end] # => 6 # we also have popfirst! and pushfirst! -popfirst!(a) # => 1 and a is now [2,4,3,4,5,6] -pushfirst!(a, 7) # => [7,2,4,3,4,5,6] +popfirst!(a) # => 1 and a is now [2,4,3,4,5,6] +pushfirst!(a, 7) # => [7,2,4,3,4,5,6] # Function names that end in exclamations points indicate that they modify # their argument. arr = [5,4,6] # => 3-element Int64 Array: [5,4,6] -sort(arr) # => [4,5,6]; arr is still [5,4,6] -sort!(arr) # => [4,5,6]; arr is now [4,5,6] +sort(arr) # => [4,5,6]; arr is still [5,4,6] +sort!(arr) # => [4,5,6]; arr is now [4,5,6] # Looking out of bounds is a BoundsError try @@ -221,20 +221,20 @@ a[2:end] # => [2, 3, 4, 5] # Remove elements from an array by index with splice! arr = [3,4,5] -splice!(arr, 2) # => 4 ; arr is now [3,5] +splice!(arr, 2) # => 4 ; arr is now [3,5] # Concatenate lists with append! b = [1,2,3] -append!(a, b) # Now a is [1, 2, 3, 4, 5, 1, 2, 3] +append!(a, b) # Now a is [1, 2, 3, 4, 5, 1, 2, 3] # Check for existence in a list with in -in(1, a) # => true +in(1, a) # => true # Examine the length with length -length(a) # => 8 +length(a) # => 8 # Tuples are immutable. -tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. +tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. tup[1] # => 1 try tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) @@ -243,12 +243,12 @@ catch e end # Many list functions also work on tuples -length(tup) # => 3 +length(tup) # => 3 tup[1:2] # => (1,2) -in(2, tup) # => true +in(2, tup) # => true # You can unpack tuples into variables -a, b, c = (1, 2, 3) # => (1,2,3) # a is now 1, b is now 2 and c is now 3 +a, b, c = (1, 2, 3) # => (1,2,3) # a is now 1, b is now 2 and c is now 3 # Tuples are created even if you leave out the parentheses d, e, f = 4, 5, 6 # => (4,5,6) @@ -258,11 +258,11 @@ d, e, f = 4, 5, 6 # => (4,5,6) (1) == 1 # => true # Look how easy it is to swap two values -e, d = d, e # => (5,4) # d is now 5 and e is now 4 +e, d = d, e # => (5,4) # d is now 5 and e is now 4 # Dictionaries store mappings -empty_dict = Dict() # => Dict{Any,Any}() +empty_dict = Dict() # => Dict{Any,Any}() # You can create a dictionary using a literal filled_dict = Dict("one" => 1, "two" => 2, "three" => 3) @@ -282,10 +282,10 @@ values(filled_dict) # Note - Same as above regarding key ordering. # Check for existence of keys in a dictionary with in, haskey -in(("one" => 1), filled_dict) # => true -in(("two" => 3), filled_dict) # => false -haskey(filled_dict, "one") # => true -haskey(filled_dict, 1) # => false +in(("one" => 1), filled_dict) # => true +in(("two" => 3), filled_dict) # => false +haskey(filled_dict, "one") # => true +haskey(filled_dict, 1) # => false # Trying to look up a non-existent key will raise an error try @@ -296,26 +296,26 @@ end # Use the get method to avoid that error by providing a default value # get(dictionary,key,default_value) -get(filled_dict, "one", 4) # => 1 -get(filled_dict, "four", 4) # => 4 +get(filled_dict, "one", 4) # => 1 +get(filled_dict, "four", 4) # => 4 # Use Sets to represent collections of unordered, unique values -empty_set = Set() # => Set{Any}() +empty_set = Set() # => Set{Any}() # Initialize a set with values -filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) +filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) # Add more values to a set -push!(filled_set, 5) # => Set{Int64}(5,4,2,3,1) +push!(filled_set, 5) # => Set{Int64}(5,4,2,3,1) # Check if the values are in the set -in(2, filled_set) # => true -in(10, filled_set) # => false +in(2, filled_set) # => true +in(10, filled_set) # => false # There are functions for set intersection, union, and difference. -other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) -intersect(filled_set, other_set) # => Set{Int64}(3,4,5) -union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set{Int64}(1,4) +other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) +intersect(filled_set, other_set) # => Set{Int64}(3,4,5) +union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) +setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set{Int64}(1,4) #################################################### @@ -409,15 +409,15 @@ function add(x, y) x + y end -add(5, 6) # => 11 after printing out "x is 5 and y is 6" +add(5, 6) # => 11 after printing out "x is 5 and y is 6" # Compact assignment of functions f_add(x, y) = x + y # => "f (generic function with 1 method)" -f_add(3, 4) # => 7 +f_add(3, 4) # => 7 # Function can also return multiple values as tuple fn(x, y) = x + y, x - y -fn(3, 4) # => (7, -1) +fn(3, 4) # => (7, -1) # You can define functions that take a variable number of # positional arguments @@ -427,16 +427,16 @@ function varargs(args...) end # => varargs (generic function with 1 method) -varargs(1, 2, 3) # => (1,2,3) +varargs(1, 2, 3) # => (1,2,3) # The ... is called a splat. # We just used it in a function definition. # It can also be used in a function call, # where it will splat an Array or Tuple's contents into the argument list. -add([5,6]...) # this is equivalent to add(5,6) +add([5,6]...) # this is equivalent to add(5,6) -x = (5, 6) # => (5,6) -add(x...) # this is equivalent to add(5,6) +x = (5, 6) # => (5,6) +add(x...) # this is equivalent to add(5,6) # You can define functions with optional positional arguments @@ -444,24 +444,24 @@ function defaults(a, b, x=5, y=6) return "$a $b and $x $y" end -defaults('h', 'g') # => "h g and 5 6" -defaults('h', 'g', 'j') # => "h g and j 6" -defaults('h', 'g', 'j', 'k') # => "h g and j k" +defaults('h', 'g') # => "h g and 5 6" +defaults('h', 'g', 'j') # => "h g and j 6" +defaults('h', 'g', 'j', 'k') # => "h g and j k" try - defaults('h') # => ERROR: no method defaults(Char,) - defaults() # => ERROR: no methods defaults() + defaults('h') # => ERROR: no method defaults(Char,) + defaults() # => ERROR: no methods defaults() catch e println(e) end # You can define functions that take keyword arguments -function keyword_args(;k1=4, name2="hello") # note the ; +function keyword_args(;k1=4, name2="hello") # note the ; return Dict("k1" => k1, "name2" => name2) end -keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] -keyword_args(k1="mine") # => ["k1"=>"mine","name2"=>"hello"] -keyword_args() # => ["name2"=>"hello","k1"=>4] +keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] +keyword_args(k1="mine") # => ["k1"=>"mine","name2"=>"hello"] +keyword_args() # => ["name2"=>"hello","k1"=>4] # You can combine all kinds of arguments in the same function function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo") @@ -485,7 +485,7 @@ function create_adder(x) end # This is "stabby lambda syntax" for creating anonymous functions -(x -> x > 2)(3) # => true +(x -> x > 2)(3) # => true # This function is identical to create_adder implementation above. function create_adder(x) @@ -501,12 +501,12 @@ function create_adder(x) end add_10 = create_adder(10) -add_10(3) # => 13 +add_10(3) # => 13 # There are built-in higher order functions -map(add_10, [1,2,3]) # => [11, 12, 13] -filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] +map(add_10, [1,2,3]) # => [11, 12, 13] +filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # We can use list comprehensions for nicer maps [add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] @@ -519,11 +519,11 @@ filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # Julia has a type system. # Every value has a type; variables do not have types themselves. # You can use the `typeof` function to get the type of a value. -typeof(5) # => Int64 +typeof(5) # => Int64 # Types are first-class values -typeof(Int64) # => DataType -typeof(DataType) # => DataType +typeof(Int64) # => DataType +typeof(DataType) # => DataType # DataType is the type that represents types, including itself. # Types are used for documentation, optimizations, and dispatch. @@ -544,10 +544,10 @@ end # The default constructor's arguments are the properties # of the type, in the order they are listed in the definition -tigger = Tiger(3.5, "orange") # => Tiger(3.5,"orange") +tigger = Tiger(3.5, "orange") # => Tiger(3.5,"orange") # The type doubles as the constructor function for values of that type -sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") +sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") # These struct-style types are called concrete types # They can be instantiated, but cannot have subtypes. @@ -559,32 +559,32 @@ abstract type Cat end # just a name and point in the type hierarchy # Abstract types cannot be instantiated, but can have subtypes. using InteractiveUtils # defines the subtype and supertype function # For example, Number is an abstract type -subtypes(Number) # => 2-element Array{Any,1}: +subtypes(Number) # => 2-element Array{Any,1}: # Complex{T<:Real} # Real -subtypes(Cat) # => 0-element Array{Any,1} +subtypes(Cat) # => 0-element Array{Any,1} # AbstractString, as the name implies, is also an abstract type -subtypes(AbstractString) # 4-element Array{Any,1}: +subtypes(AbstractString) # 4-element Array{Any,1}: # String # SubString # SubstitutionString # Test.GenericString # Every type has a super type; use the `supertype` function to get it. -typeof(5) # => Int64 -supertype(Int64) # => Signed -supertype(Signed) # => Integer -supertype(Integer) # => Real -supertype(Real) # => Number -supertype(Number) # => Any -supertype(supertype(Signed)) # => Real -supertype(Any) # => Any +typeof(5) # => Int64 +supertype(Int64) # => Signed +supertype(Signed) # => Integer +supertype(Integer) # => Real +supertype(Real) # => Number +supertype(Number) # => Any +supertype(supertype(Signed)) # => Real +supertype(Any) # => Any # All of these type, except for Int64, are abstract. -typeof("fire") # => String -supertype(String) # => AbstractString +typeof("fire") # => String +supertype(String) # => AbstractString # Likewise here with String -supertype(SubString) # => AbstractString +supertype(SubString) # => AbstractString # <: is the subtyping operator struct Lion <: Cat # Lion is a subtype of Cat @@ -631,9 +631,9 @@ function meow(animal::Tiger) end # Testing the meow function -meow(tigger) # => "rawwr" -meow(Lion("brown", "ROAAR")) # => "ROAAR" -meow(Panther()) # => "grrr" +meow(tigger) # => "rawwr" +meow(Lion("brown", "ROAAR")) # => "ROAAR" +meow(Panther()) # => "grrr" # Review the local type hierarchy Tiger <: Cat # => false @@ -645,9 +645,9 @@ function pet_cat(cat::Cat) println("The cat says $(meow(cat))") end -pet_cat(Lion("42")) # => prints "The cat says 42" +pet_cat(Lion("42")) # => prints "The cat says 42" try - pet_cat(tigger) # => ERROR: no method pet_cat(Tiger,) + pet_cat(tigger) # => ERROR: no method pet_cat(Tiger,) catch e println(e) end @@ -662,21 +662,21 @@ function fight(t::Tiger, c::Cat) end # => fight (generic function with 1 method) -fight(tigger, Panther()) # => prints The orange tiger wins! -fight(tigger, Lion("ROAR")) # => prints The orange tiger wins! +fight(tigger, Panther()) # => prints The orange tiger wins! +fight(tigger, Lion("ROAR")) # => prints The orange tiger wins! # Let's change the behavior when the Cat is specifically a Lion fight(t::Tiger, l::Lion) = println("The $(l.mane_color)-maned lion wins!") # => fight (generic function with 2 methods) -fight(tigger, Panther()) # => prints The orange tiger wins! -fight(tigger, Lion("ROAR")) # => prints The green-maned lion wins! +fight(tigger, Panther()) # => prints The orange tiger wins! +fight(tigger, Lion("ROAR")) # => prints The green-maned lion wins! # We don't need a Tiger in order to fight fight(l::Lion, c::Cat) = println("The victorious cat says $(meow(c))") # => fight (generic function with 3 methods) -fight(Lion("balooga!"), Panther()) # => prints The victorious cat says grrr +fight(Lion("balooga!"), Panther()) # => prints The victorious cat says grrr try fight(Panther(), Lion("RAWR")) catch e @@ -689,7 +689,7 @@ fight(c::Cat, l::Lion) = println("The cat beats the Lion") # This warning is because it's unclear which fight will be called in: try - fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The victorious cat says rarrr + fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The victorious cat says rarrr catch e println(e) # => MethodError(fight, (Lion("green", "RAR"), Lion("brown", "rarrr")), 0x000000000000557c) @@ -697,7 +697,7 @@ end # The result may be different in other versions of Julia fight(l::Lion, l2::Lion) = println("The lions come to a tie") -fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The lions come to a tie +fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The lions come to a tie # Under the hood @@ -705,7 +705,7 @@ fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The lions come to a tie square_area(l) = l * l # square_area (generic function with 1 method) -square_area(5) #25 +square_area(5) #25 # What happens when we feed square_area an integer? code_native(square_area, (Int32,)) @@ -746,7 +746,7 @@ code_native(square_area, (Float64,)) # arguments are floats. # Let's calculate the area of a circle circle_area(r) = pi * r * r # circle_area (generic function with 1 method) -circle_area(5) # 78.53981633974483 +circle_area(5) # 78.53981633974483 code_native(circle_area, (Int32,)) # .section __TEXT,__text,regular,pure_instructions -- cgit v1.2.3 From 9fab30a26a0de8603b19b95055f68af031c906bb Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Wed, 15 Aug 2018 16:54:03 +0200 Subject: one more quick run over the code --- julia.html.markdown | 109 ++++++++++++++++++++++++---------------------------- 1 file changed, 51 insertions(+), 58 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index e5706062..71331818 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -30,7 +30,7 @@ This is based on Julia 1.0.0 3 # => 3 (Int64) 3.2 # => 3.2 (Float64) 2 + 1im # => 2 + 1im (Complex{Int64}) -2 // 3 # => 2//3 (Rational{Int64}) +2 // 3 # => 2 // 3 (Rational{Int64}) # All of the normal infix operators are available. 1 + 1 # => 2 @@ -81,29 +81,18 @@ false 2 < 3 < 2 # => false # Strings are created with " -try - "This is a string." -catch ; end - -# Julia has several types of strings, including ASCIIString and UTF8String. -# More on this in the Types section. +"This is a string." # Character literals are written with ' -try - 'a' -catch ; end +'a' -# Some strings can be indexed like an array of characters -try - "This is a string"[1] # => 'T' # Julia indexes from 1 -catch ; end -# However, this is will not work well for UTF8 strings, -# so iterating over strings is recommended (map, for loops, etc). +# Strings are UTF8 encoded. Only if they contain only ASCII characters can +# they be safely indexed. +ascii("This is a string")[1] # => 'T' # Julia indexes from 1 +# Otherwise, iterating over strings is recommended (map, for loops, etc). # $ can be used for string interpolation: -try - "2 + 2 = $(2 + 2)" # => "2 + 2 = 4" -catch ; end +"2 + 2 = $(2 + 2)" # => "2 + 2 = 4" # You can put any Julia expression inside the parentheses. # Another way to format strings is the printf macro from the stdlib Printf. @@ -157,19 +146,19 @@ SomeOtherVar123! = 6 # => 6 # functions are sometimes called mutating functions or in-place functions. # Arrays store a sequence of values indexed by integers 1 through n: -a = Int64[] # => 0-element Int64 Array +a = Int64[] # => 0-element Int64 Array # 1-dimensional array literals can be written with comma-separated values. -b = [4, 5, 6] # => 3-element Int64 Array: [4, 5, 6] -b = [4; 5; 6] # => 3-element Int64 Array: [4, 5, 6] -b[1] # => 4 -b[end] # => 6 +b = [4, 5, 6] # => 3-element Int64 Array: [4, 5, 6] +b = [4; 5; 6] # => 3-element Int64 Array: [4, 5, 6] +b[1] # => 4 +b[end] # => 6 # 2-dimensional arrays use space-separated values and semicolon-separated rows. -matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] +matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] -# Arrays of a particular Type -b = Int8[4, 5, 6] # => 3-element Int8 Array: [4, 5, 6] +# Arrays of a particular type +b = Int8[4, 5, 6] # => 3-element Int8 Array: [4, 5, 6] # Add stuff to the end of a list with push! and append! push!(a, 1) # => [1] @@ -184,11 +173,11 @@ pop!(b) # => 6 and b is now [4,5] # Let's put it back push!(b, 6) # b is now [4,5,6] again. -a[1] # => 1 # remember that Julia indexes from 1, not 0! +a[1] # => 1 # remember that Julia indexes from 1, not 0! # end is a shorthand for the last index. It can be used in any # indexing expression -a[end] # => 6 +a[end] # => 6 # we also have popfirst! and pushfirst! popfirst!(a) # => 1 and a is now [2,4,3,4,5,6] @@ -196,28 +185,30 @@ pushfirst!(a, 7) # => [7,2,4,3,4,5,6] # Function names that end in exclamations points indicate that they modify # their argument. -arr = [5,4,6] # => 3-element Int64 Array: [5,4,6] +arr = [5,4,6] # => 3-element Int64 Array: [5,4,6] sort(arr) # => [4,5,6]; arr is still [5,4,6] sort!(arr) # => [4,5,6]; arr is now [4,5,6] # Looking out of bounds is a BoundsError try - a[0] # => ERROR: BoundsError() in getindex at array.jl:270 - a[end + 1] # => ERROR: BoundsError() in getindex at array.jl:270 + a[0] + # => BoundsError: attempt to access 7-element Array{Int64,1} at index [0] + a[end + 1] + # => BoundsError: attempt to access 7-element Array{Int64,1} at index [8] catch e println(e) end # Errors list the line and file they came from, even if it's in the standard -# library. If you built Julia from source, you can look in the folder base -# inside the julia folder to find these files. +# library. You can look in the folder share/julia inside the julia folder to +# find these files. # You can initialize arrays from ranges -a = [1:5;] # => 5-element Int64 Array: [1,2,3,4,5] +a = [1:5;] # => 5-element Int64 Array: [1,2,3,4,5] # You can look at ranges with slice syntax. -a[1:3] # => [1, 2, 3] -a[2:end] # => [2, 3, 4, 5] +a[1:3] # => [1, 2, 3] +a[2:end] # => [2, 3, 4, 5] # Remove elements from an array by index with splice! arr = [3,4,5] @@ -235,16 +226,16 @@ length(a) # => 8 # Tuples are immutable. tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. -tup[1] # => 1 +tup[1] # => 1 try tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) catch e println(e) end -# Many list functions also work on tuples +# Many array functions also work on tuples length(tup) # => 3 -tup[1:2] # => (1,2) +tup[1:2] # => (1,2) in(2, tup) # => true # You can unpack tuples into variables @@ -266,19 +257,20 @@ empty_dict = Dict() # => Dict{Any,Any}() # You can create a dictionary using a literal filled_dict = Dict("one" => 1, "two" => 2, "three" => 3) -# => Dict{ASCIIString,Int64} +# => Dict{String,Int64} # Look up values with [] -filled_dict["one"] # => 1 +filled_dict["one"] # => 1 # Get all keys keys(filled_dict) -# => KeyIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +# => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys: +# "two", "one", "three" # Note - dictionary keys are not sorted or in the order you inserted them. # Get all values values(filled_dict) -# => ValueIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +# => Base.ValueIterator{Dict{String,Int64}} with 3 entries. Values: 2, 1, 3 # Note - Same as above regarding key ordering. # Check for existence of keys in a dictionary with in, haskey @@ -289,33 +281,33 @@ haskey(filled_dict, 1) # => false # Trying to look up a non-existent key will raise an error try - filled_dict["four"] # => ERROR: key not found: four in getindex at dict.jl:489 + filled_dict["four"] # => KeyError: key "four" not found catch e println(e) end # Use the get method to avoid that error by providing a default value -# get(dictionary,key,default_value) +# get(dictionary, key, default_value) get(filled_dict, "one", 4) # => 1 get(filled_dict, "four", 4) # => 4 # Use Sets to represent collections of unordered, unique values empty_set = Set() # => Set{Any}() # Initialize a set with values -filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) +filled_set = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1]) # Add more values to a set -push!(filled_set, 5) # => Set{Int64}(5,4,2,3,1) +push!(filled_set, 5) # => Set([4, 2, 3, 5, 1]) # Check if the values are in the set in(2, filled_set) # => true in(10, filled_set) # => false # There are functions for set intersection, union, and difference. -other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) -intersect(filled_set, other_set) # => Set{Int64}(3,4,5) -union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set{Int64}(1,4) +other_set = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6]) +intersect(filled_set, other_set) # => Set([4, 3, 5]) +union(filled_set, other_set) # => Set([4, 2, 3, 5, 6, 1]) +setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1]) #################################################### @@ -356,8 +348,9 @@ end # cat is a mammal # mouse is a mammal -for a in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") - println("$(a[1]) is a $(a[2])") +for pair in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") + from, to = pair + println("$from is a $to") end # prints: # dog is a mammal @@ -509,8 +502,8 @@ map(add_10, [1,2,3]) # => [11, 12, 13] filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # We can use list comprehensions for nicer maps -[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] -[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] #################################################### ## 5. Types @@ -703,9 +696,9 @@ fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The lions come to a tie # Under the hood # You can take a look at the llvm and the assembly code generated. -square_area(l) = l * l # square_area (generic function with 1 method) +square_area(l) = l * l # square_area (generic function with 1 method) -square_area(5) #25 +square_area(5) # => 25 # What happens when we feed square_area an integer? code_native(square_area, (Int32,)) -- cgit v1.2.3 From 843ba7019323e6e7411cae9d4c0fa83ce98baf92 Mon Sep 17 00:00:00 2001 From: Martijn Visser Date: Wed, 15 Aug 2018 17:00:35 +0200 Subject: wrap lines longer than 80 --- julia.html.markdown | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/julia.html.markdown b/julia.html.markdown index 71331818..07a051e1 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -55,7 +55,7 @@ xor(2, 4) # => 6 # bitwise xor 2 >> 1 # => 1 # arithmetic shift right 2 << 1 # => 4 # logical/arithmetic shift left -# You can use the bitstring function to see the binary representation of a number. +# Use the bitstring function to see the binary representation of a number. bitstring(12345) # => "0000000000000000000000000000000000000000000000000011000000111001" bitstring(12345.0) @@ -674,7 +674,8 @@ try fight(Panther(), Lion("RAWR")) catch e println(e) - # => MethodError(fight, (Panther("green"), Lion("green", "RAWR")), 0x000000000000557b) + # => MethodError(fight, (Panther("green"), Lion("green", "RAWR")), + # 0x000000000000557b) end # Also let the cat go first @@ -682,10 +683,12 @@ fight(c::Cat, l::Lion) = println("The cat beats the Lion") # This warning is because it's unclear which fight will be called in: try - fight(Lion("RAR"), Lion("brown", "rarrr")) # => prints The victorious cat says rarrr + fight(Lion("RAR"), Lion("brown", "rarrr")) + # => prints The victorious cat says rarrr catch e println(e) - # => MethodError(fight, (Lion("green", "RAR"), Lion("brown", "rarrr")), 0x000000000000557c) + # => MethodError(fight, (Lion("green", "RAR"), Lion("brown", "rarrr")), + # 0x000000000000557c) end # The result may be different in other versions of Julia -- cgit v1.2.3