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[julia/en] fix for #1483

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This commit is contained in:
Keith Miyake 2018-10-04 12:34:19 -07:00
parent e867dfd7b6
commit f894add86a
1 changed files with 77 additions and 77 deletions
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julia.html.markdown
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@ -114,12 +114,12 @@ println("I'm Julia. Nice to meet you!") # => I'm Julia. Nice to meet you!
#################################################### ####################################################
# You don't declare variables before assigning to them. # You don't declare variables before assigning to them.
some_var = 5 # => 5 someVar = 5 # => 5
some_var # => 5 someVar # => 5
# Accessing a previously unassigned variable is an error # Accessing a previously unassigned variable is an error
try try
some_other_var # => ERROR: UndefVarError: some_other_var not defined someOtherVar # => ERROR: UndefVarError: someOtherVar not defined
catch e catch e
println(e) println(e)
end end
@ -286,62 +286,62 @@ d # => 5
e # => 4 e # => 4
# Dictionaries store mappings # Dictionaries store mappings
empty_dict = Dict() # => Dict{Any,Any} with 0 entries emptyDict = Dict() # => Dict{Any,Any} with 0 entries
# You can create a dictionary using a literal # You can create a dictionary using a literal
filled_dict = Dict("one" => 1, "two" => 2, "three" => 3) filledDict = Dict("one" => 1, "two" => 2, "three" => 3)
# => Dict{String,Int64} with 3 entries: # => Dict{String,Int64} with 3 entries:
# => "two" => 2, "one" => 1, "three" => 3 # => "two" => 2, "one" => 1, "three" => 3
# Look up values with [] # Look up values with []
filled_dict["one"] # => 1 filledDict["one"] # => 1
# Get all keys # Get all keys
keys(filled_dict) keys(filledDict)
# => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys: # => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys:
# => "two", "one", "three" # => "two", "one", "three"
# Note - dictionary keys are not sorted or in the order you inserted them. # Note - dictionary keys are not sorted or in the order you inserted them.
# Get all values # Get all values
values(filled_dict) values(filledDict)
# => Base.ValueIterator for a Dict{String,Int64} with 3 entries. Values: # => Base.ValueIterator for a Dict{String,Int64} with 3 entries. Values:
# => 2, 1, 3 # => 2, 1, 3
# Note - Same as above regarding key ordering. # Note - Same as above regarding key ordering.
# Check for existence of keys in a dictionary with in, haskey # Check for existence of keys in a dictionary with in, haskey
in(("one" => 1), filled_dict) # => true in(("one" => 1), filledDict) # => true
in(("two" => 3), filled_dict) # => false in(("two" => 3), filledDict) # => false
haskey(filled_dict, "one") # => true haskey(filledDict, "one") # => true
haskey(filled_dict, 1) # => false haskey(filledDict, 1) # => false
# Trying to look up a non-existent key will raise an error # Trying to look up a non-existent key will raise an error
try try
filled_dict["four"] # => ERROR: KeyError: key "four" not found filledDict["four"] # => ERROR: KeyError: key "four" not found
catch e catch e
println(e) println(e)
end end
# Use the get method to avoid that error by providing a default value # Use the get method to avoid that error by providing a default value
# get(dictionary, key, default_value) # get(dictionary, key, defaultValue)
get(filled_dict, "one", 4) # => 1 get(filledDict, "one", 4) # => 1
get(filled_dict, "four", 4) # => 4 get(filledDict, "four", 4) # => 4
# Use Sets to represent collections of unordered, unique values # Use Sets to represent collections of unordered, unique values
empty_set = Set() # => Set(Any[]) emptySet = Set() # => Set(Any[])
# Initialize a set with values # Initialize a set with values
filled_set = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1]) filledSet = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1])
# Add more values to a set # Add more values to a set
push!(filled_set, 5) # => Set([4, 2, 3, 5, 1]) push!(filledSet, 5) # => Set([4, 2, 3, 5, 1])
# Check if the values are in the set # Check if the values are in the set
in(2, filled_set) # => true in(2, filledSet) # => true
in(10, filled_set) # => false in(10, filledSet) # => false
# There are functions for set intersection, union, and difference. # There are functions for set intersection, union, and difference.
other_set = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6]) otherSet = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6])
intersect(filled_set, other_set) # => Set([4, 3, 5]) intersect(filledSet, otherSet) # => Set([4, 3, 5])
union(filled_set, other_set) # => Set([4, 2, 3, 5, 6, 1]) union(filledSet, otherSet) # => Set([4, 2, 3, 5, 6, 1])
setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1]) setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1])
#################################################### ####################################################
@ -349,15 +349,15 @@ setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1])
#################################################### ####################################################
# Let's make a variable # Let's make a variable
some_var = 5 someVar = 5
# Here is an if statement. Indentation is not meaningful in Julia. # Here is an if statement. Indentation is not meaningful in Julia.
if some_var > 10 if someVar > 10
println("some_var is totally bigger than 10.") println("someVar is totally bigger than 10.")
elseif some_var < 10 # This elseif clause is optional. elseif someVar < 10 # This elseif clause is optional.
println("some_var is smaller than 10.") println("someVar is smaller than 10.")
else # The else clause is optional too. else # The else clause is optional too.
println("some_var is indeed 10.") println("someVar is indeed 10.")
end end
# => prints "some var is smaller than 10" # => prints "some var is smaller than 10"
@ -434,8 +434,8 @@ add(5, 6)
# => 11 # => 11
# Compact assignment of functions # Compact assignment of functions
f_add(x, y) = x + y # => f_add (generic function with 1 method) fAdd(x, y) = x + y # => fAdd (generic function with 1 method)
f_add(3, 4) # => 7 fAdd(3, 4) # => 7
# Function can also return multiple values as tuple # Function can also return multiple values as tuple
fn(x, y) = x + y, x - y # => fn (generic function with 1 method) fn(x, y) = x + y, x - y # => fn (generic function with 1 method)
@ -478,67 +478,67 @@ catch e
end end
# You can define functions that take keyword arguments # You can define functions that take keyword arguments
function keyword_args(;k1=4, name2="hello") # note the ; function keywordArgs(;k1=4, name2="hello") # note the ;
return Dict("k1" => k1, "name2" => name2) return Dict("k1" => k1, "name2" => name2)
end end
# => keyword_args (generic function with 1 method) # => keywordArgs (generic function with 1 method)
keyword_args(name2="ness") # => ["name2"=>"ness", "k1"=>4] keywordArgs(name2="ness") # => ["name2"=>"ness", "k1"=>4]
keyword_args(k1="mine") # => ["name2"=>"hello", "k1"=>"mine"] keywordArgs(k1="mine") # => ["name2"=>"hello", "k1"=>"mine"]
keyword_args() # => ["name2"=>"hello", "k1"=>4] keywordArgs() # => ["name2"=>"hello", "k1"=>4]
# You can combine all kinds of arguments in the same function # You can combine all kinds of arguments in the same function
function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo") function allTheArgs(normalArg, optionalPositionalArg=2; keywordArg="foo")
println("normal arg: $normal_arg") println("normal arg: $normalArg")
println("optional arg: $optional_positional_arg") println("optional arg: $optionalPositionalArg")
println("keyword arg: $keyword_arg") println("keyword arg: $keywordArg")
end end
# => all_the_args (generic function with 2 methods) # => allTheArgs (generic function with 2 methods)
all_the_args(1, 3, keyword_arg=4) allAheArgs(1, 3, keywordArg=4)
# => normal arg: 1 # => normal arg: 1
# => optional arg: 3 # => optional arg: 3
# => keyword arg: 4 # => keyword arg: 4
# Julia has first class functions # Julia has first class functions
function create_adder(x) function createAdder(x)
adder = function (y) adder = function (y)
return x + y return x + y
end end
return adder return adder
end end
# => create_adder (generic function with 1 method) # => createAdder (generic function with 1 method)
# This is "stabby lambda syntax" for creating anonymous functions # 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. # This function is identical to createAdder implementation above.
function create_adder(x) function createAdder(x)
y -> x + y y -> x + y
end end
# => create_adder (generic function with 1 method) # => createAdder (generic function with 1 method)
# You can also name the internal function, if you want # You can also name the internal function, if you want
function create_adder(x) function createAdder(x)
function adder(y) function adder(y)
x + y x + y
end end
adder adder
end end
# => create_adder (generic function with 1 method) # => createAdder (generic function with 1 method)
add_10 = create_adder(10) # => (::getfield(Main, Symbol("#adder#11")){Int64}) add10 = createAdder(10) # => (::getfield(Main, Symbol("#adder#11")){Int64})
# (generic function with 1 method) # (generic function with 1 method)
add_10(3) # => 13 add10(3) # => 13
# There are built-in higher order functions # There are built-in higher order functions
map(add_10, [1,2,3]) # => [11, 12, 13] map(add10, [1,2,3]) # => [11, 12, 13]
filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7]
# We can use list comprehensions # We can use list comprehensions
[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] [add10(i) for i = [1, 2, 3]] # => [11, 12, 13]
[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] [add10(i) for i in [1, 2, 3]] # => [11, 12, 13]
[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] [x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7]
#################################################### ####################################################
@ -616,7 +616,7 @@ supertype(SubString) # => AbstractString
# <: is the subtyping operator # <: is the subtyping operator
struct Lion <: Cat # Lion is a subtype of Cat struct Lion <: Cat # Lion is a subtype of Cat
mane_color maneColor
roar::AbstractString roar::AbstractString
end end
@ -627,7 +627,7 @@ Lion(roar::AbstractString) = Lion("green", roar)
# This is an outer constructor because it's outside the type definition # This is an outer constructor because it's outside the type definition
struct Panther <: Cat # Panther is also a subtype of Cat struct Panther <: Cat # Panther is also a subtype of Cat
eye_color eyeColor
Panther() = new("green") Panther() = new("green")
# Panthers will only have this constructor, and no default constructor. # Panthers will only have this constructor, and no default constructor.
end end
@ -669,14 +669,14 @@ Lion <: Cat # => true
Panther <: Cat # => true Panther <: Cat # => true
# Defining a function that takes Cats # Defining a function that takes Cats
function pet_cat(cat::Cat) function petCat(cat::Cat)
println("The cat says $(meow(cat))") println("The cat says $(meow(cat))")
end end
# => pet_cat (generic function with 1 method) # => petCat (generic function with 1 method)
pet_cat(Lion("42")) # => The cat says 42 petCat(Lion("42")) # => The cat says 42
try try
pet_cat(tigger) # => ERROR: MethodError: no method matching pet_cat(::Tiger) petCat(tigger) # => ERROR: MethodError: no method matching petCat(::Tiger)
catch e catch e
println(e) println(e)
end end
@ -695,7 +695,7 @@ fight(tigger, Panther()) # => The orange tiger wins!
fight(tigger, Lion("ROAR")) # => The orange tiger wins! fight(tigger, Lion("ROAR")) # => The orange tiger wins!
# Let's change the behavior when the Cat is specifically a Lion # 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.maneColor)-maned lion wins!")
# => fight (generic function with 2 methods) # => fight (generic function with 2 methods)
fight(tigger, Panther()) # => The orange tiger wins! fight(tigger, Panther()) # => The orange tiger wins!
@ -744,14 +744,14 @@ fight(Lion("RAR"), Lion("brown", "rarrr")) # => The lions come to a tie
# Under the hood # Under the hood
# You can take a look at the llvm and the assembly code generated. # 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) squareArea(l) = l * l # squareArea (generic function with 1 method)
square_area(5) # => 25 squareArea(5) # => 25
# What happens when we feed square_area an integer? # What happens when we feed squareArea an integer?
code_native(square_area, (Int32,), syntax = :intel) codeNative(squareArea, (Int32,), syntax = :intel)
# .text # .text
# ; Function square_area { # ; Function squareArea {
# ; Location: REPL[116]:1 # Prologue # ; Location: REPL[116]:1 # Prologue
# push rbp # push rbp
# mov rbp, rsp # mov rbp, rsp
@ -765,9 +765,9 @@ code_native(square_area, (Int32,), syntax = :intel)
# nop dword ptr [rax + rax] # nop dword ptr [rax + rax]
# ;} # ;}
code_native(square_area, (Float32,), syntax = :intel) codeNative(squareArea, (Float32,), syntax = :intel)
# .text # .text
# ; Function square_area { # ; Function squareArea {
# ; Location: REPL[116]:1 # ; Location: REPL[116]:1
# push rbp # push rbp
# mov rbp, rsp # mov rbp, rsp
@ -780,9 +780,9 @@ code_native(square_area, (Float32,), syntax = :intel)
# nop word ptr [rax + rax] # nop word ptr [rax + rax]
# ;} # ;}
code_native(square_area, (Float64,), syntax = :intel) codeNative(squareArea, (Float64,), syntax = :intel)
# .text # .text
# ; Function square_area { # ; Function squareArea {
# ; Location: REPL[116]:1 # ; Location: REPL[116]:1
# push rbp # push rbp
# mov rbp, rsp # mov rbp, rsp
@ -798,12 +798,12 @@ code_native(square_area, (Float64,), syntax = :intel)
# Note that julia will use floating point instructions if any of the # Note that julia will use floating point instructions if any of the
# arguments are floats. # arguments are floats.
# Let's calculate the area of a circle # Let's calculate the area of a circle
circle_area(r) = pi * r * r # circle_area (generic function with 1 method) circleArea(r) = pi * r * r # circleArea (generic function with 1 method)
circle_area(5) # 78.53981633974483 circleArea(5) # 78.53981633974483
code_native(circle_area, (Int32,), syntax = :intel) codeNative(circleArea, (Int32,), syntax = :intel)
# .text # .text
# ; Function circle_area { # ; Function circleArea {
# ; Location: REPL[121]:1 # ; Location: REPL[121]:1
# push rbp # push rbp
# mov rbp, rsp # mov rbp, rsp
@ -832,9 +832,9 @@ code_native(circle_area, (Int32,), syntax = :intel)
# nop dword ptr [rax] # nop dword ptr [rax]
# ;} # ;}
code_native(circle_area, (Float64,), syntax = :intel) codeNative(circleArea, (Float64,), syntax = :intel)
# .text # .text
# ; Function circle_area { # ; Function circleArea {
# ; Location: REPL[121]:1 # ; Location: REPL[121]:1
# push rbp # push rbp
# mov rbp, rsp # mov rbp, rsp