<codeware/>
how to present code
your slides are not your IDE
$> not your console either
here are five rules for
presenting code
rule 1:
$ use monospaced font
$
or
monospace
proportional
monospace
proportional
fixed or variable
fixed or variable
var power = function(base, exponent) {
var result = 1;
for (var count = 0; count < exponent; count++)
result *= base;
return result;
};
var power = function(base, exponent) {
var result = 1;
for (var count = 0; count < exponent; count++)
result *= base;
return result;
};
monospace
proportional
var power = function(base, exponent) {
var result = 1;
for (var count = 0; count < exponent; count++)
result *= base;
return result;
};
var power = function(base, exponent) {
var result = 1;
for (var count = 0; count < exponent; count++)
result *= base;
return result;
};
monospace
proportional
monospace
monospaced fonts
have better readability
when presenting code
proportional
monospace
proportional it is harder to follow code
with proportional fonts
monospaced fonts
have better readability
when presenting code
use monospaced fonts
for code readability
rule 2:
$ use big fonts
$
presenting for a big audience?
$ this is not your desktop monitor
$ font size should be bigger
$
I mean BIGGER
than your think
I really mean BIGGER

than your think
console.log(“even BIGGER where possible”)
console
.log(“use line breaks”)
<body>
<button onClick=“coolFunction()” autofocus>too small</button>
</body>
<body>
<button
onClick=“coolFunction()”
autofocus>
same but BIGGER
</button>
</body>
BIGGER is betterhow do you expect people in the back to read this?
rule 3:
$ smart syntax

highlighting
$
this is not your IDE
use syntax highlighting
only where needed
this is not your IDE
use syntax highlighting
only where needed
Presenting code on your slides
usually results in a wall of text.
Highlight only the

specific parts you want your
audience to focus on.
Presenting code on your slides
usually results in a wall of text.
Highlight only the

specific parts you want your
audience to focus on.
Presenting code on your slides
usually results in a wall of text.
Highlight only the

specific parts you want your
audience to focus on.
3 slides example - Ruby map function
1
2
3
names = ['rey', 'fin', 'poe']
names.map! {|name| name.capitalize }
puts names
3 slides example - Ruby map function
1
2
3
names = ['rey', 'fin', 'poe']
names.map! {|name| name.capitalize }
puts names
3 slides example - Ruby map function
1
2
3
names = ['rey', 'fin', 'poe']
names.map! {|name| name.capitalize }
puts names
# output
Rey
Fin
Poe
3 slides example - Ruby map function
1
2
3
rule 4:
$ using ellipsis…
$
import sys
from ortools.constraint_solver import pywrapcp
# By default, solve the 8x8 problem.
n = 8 if len(sys.argv) < 2 else int(sys.argv[1])
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
# Creates the variables.
# The array index is the row, and the value is the column.
queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)]
# Creates the constraints.
# All columns must be different.
# (The "not on the same row" constraint is implicit from the array we're
# using to store our variables; since no two elements of an array
# can have the same index, there can be no queens with the same row.)
solver.Add(solver.AllDifferent(queens))
# No two queens can be on the same diagonal.
solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)]))
solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)]))
db = solver.Phase(queens,
solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
solver.ASSIGN_CENTER_VALUE)
solver.NewSearch(db)
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
print
print "Solutions found:", num_solutions
print "Time:", solver.WallTime(), "ms"
Solving the N-queens Problem
import sys
from ortools.constraint_solver import pywrapcp
# By default, solve the 8x8 problem.
n = 8 if len(sys.argv) < 2 else int(sys.argv[1])
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
# Creates the variables.
# The array index is the row, and the value is the column.
queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)]
# Creates the constraints.
# All columns must be different.
# (The "not on the same row" constraint is implicit from the array we're
# using to store our variables; since no two elements of an array
# can have the same index, there can be no queens with the same row.)
solver.Add(solver.AllDifferent(queens))
# No two queens can be on the same diagonal.
solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)]))
solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)]))
db = solver.Phase(queens,
solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
solver.ASSIGN_CENTER_VALUE)
solver.NewSearch(db)
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
print
print "Solutions found:", num_solutions
print "Time:", solver.WallTime(), "ms"
Solving the N-queens Problem
what’s the point in presenting all you code if
people can’t follow?
import sys
from ortools.constraint_solver import pywrapcp
# By default, solve the 8x8 problem.
n = 8 if len(sys.argv) < 2 else int(sys.argv[1])
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
# Creates the variables.
# The array index is the row, and the value is the column.
queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)]
# Creates the constraints.
# All columns must be different.
# (The "not on the same row" constraint is implicit from the array we're
# using to store our variables; since no two elements of an array
# can have the same index, there can be no queens with the same row.)
solver.Add(solver.AllDifferent(queens))
# No two queens can be on the same diagonal.
solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)]))
solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)]))
db = solver.Phase(queens,
solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
solver.ASSIGN_CENTER_VALUE)
solver.NewSearch(db)
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
print
print "Solutions found:", num_solutions
print "Time:", solver.WallTime(), "ms"
Solving the N-queens Problem
keep just the relevant code
import sys
from ortools.constraint_solver import pywrapcp
# By default, solve the 8x8 problem.
n = 8 if len(sys.argv) < 2 else int(sys.argv[1])
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
# Creates the variables.
# The array index is the row, and the value is the column.
queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)]
# Creates the constraints.
# All columns must be different.
# (The "not on the same row" constraint is implicit from the array we're
# using to store our variables; since no two elements of an array
# can have the same index, there can be no queens with the same row.)
solver.Add(solver.AllDifferent(queens))
# No two queens can be on the same diagonal.
solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)]))
solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)]))
db = solver.Phase(queens,
solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
solver.ASSIGN_CENTER_VALUE)
solver.NewSearch(db)
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
print
print "Solutions found:", num_solutions
print "Time:", solver.WallTime(), "ms"
Solving the N-queens Problem
use ellipsis…
...
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
...
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
...
Solving the N-queens Problem
...
# Creates the solver.
solver = pywrapcp.Solver("n-queens")
...
# Iterates through the solutions, displaying each.
num_solutions = 0
while solver.NextSolution():
queen_columns = [int(queens[i].Value()) for i in range(n)]
# Displays the solution just computed.
for i in range(n):
for j in range(n):
if queen_columns[i] == j:
print "Q",
else:
print "_",
print
print
num_solutions += 1
solver.EndSearch()
...
Solving the N-queens Problem
the focus is now on the algorithm

not the boilerplate
rule 5:
$ use screen annotation
$
do you want to focus your
audience’s attention on a
specific area in the screen?
thinking of using a laser
pointer?
do you expect your audience
to track this?
always create slides as if
you are the person sitting

in the last row of the
conference hall.
use screen annotations.
always create slides as if
you are the person sitting

in the last row of the
conference hall.
use screen annotations.
always create slides as if
you are the person sitting

in the last row of the
conference hall.
use screen annotations.
always create slides as if
you are the person sitting

in the last row of the
conference hall.
use screen annotations.
putting it all together
$ ECMAScript 2015 Promise example
$
putting it all together
$ ECMAScript 2015 Promise example
$
the next slides will introduce the

ECMAScript 2015 Promise Object
fetchGraphData(graphName, function(error, graphData)) {
if (error) { // handle error }
// ...
renderGraph(graphData, function(error)) {
if (error) { // handle error }
// ...
notifyClients(msg, result, function(error, response)) {
if (error) { // handle error }
// ...
});
});
});
Typical JS code results with

many nested callbacks
fetchGraphData(graphName, function(error, graphData)) {
if (error) { // handle error }
// ...
renderGraph(graphData, function(error)) {
if (error) { // handle error }
// ...
notifyClients(msg, result, function(error, response)) {
if (error) { // handle error }
// ...
});
});
});
makes it hard to follow
fetchGraphData(graphName, function(error, graphData)) {
if (error) { // handle error }
// ...
renderGraph(graphData, function(error)) {
if (error) { // handle error }
// ...
notifyClients(msg, result, function(error, response)) {
if (error) { // handle error }
// ...
});
});
});
error handling is duplicated
ECMAScript 2015 Promise
to the rescue!
function fetchGraphData(graphName) {
return new Promise(function(resolve, reject)) {
let request = new XMLHttpRequest();
...

// XMLHttpRequest to server
request.open(‘GET’, ‘http://example.com', true);
request.onload = function() {
if (request.status == 200) {
resolve(request.response);
}
else {
reject(new Error(request.status));
}
};
});
The Promise object is used for deferred and
asynchronous computations
function fetchGraphData(graphName) {
return new Promise(function(resolve, reject)) {
let request = new XMLHttpRequest();
...

// XMLHttpRequest to server
request.open(‘GET’, ‘http://example.com', true);
request.onload = function() {
if (request.status == 200) {
resolve(request.response);
}
else {
reject(new Error(request.status));
}
};
});
resolve is called once operation has completed
successfully
function fetchGraphData(graphName) {
return new Promise(function(resolve, reject)) {
let request = new XMLHttpRequest();
...

// XMLHttpRequest to server
request.open(‘GET’, ‘http://example.com', true);
request.onload = function() {
if (request.status == 200) {
resolve(request.response);
}
else {
reject(new Error(request.status));
}
};
});
reject is called if the operation has been
rejected
fetchGraphData(graphName)
.then(renderGraph)
.then(notifyClients)
.catch(function(error)) {
console.log(“Error:”, error)
});
Calling a Promise
Promise code is easy to read
fetchGraphData(graphName)
.then(renderGraph)
.then(notifyClients)
.catch(function(error)) {
console.log(“Error:”, error)
});
you can nest multiple Promise calls
Calling a Promise
fetchGraphData(graphName)
.then(renderGraph)
.then(notifyClients)
.catch(function(error)) {
console.log(“Error:”, error)
});
Calling a Promise
one error handling call
remember!

your slides are not your IDE
1
codeware - 5 rules
2 3
4 5
codeware - 5 rules
2 3
4 5
monospaced
font
codeware - 5 rules
3
4 5
monospaced
font BIG
codeware - 5 rules
4 5
monospaced
font BIG
smart syntax

highlighting
codeware - 5 rules
5
monospaced
font BIG
smart syntax
highlighting
ellipsis...
monospaced
font
codeware - 5 rules
BIG
smart syntax
highlighting
ellipsis...
screen
annotation
Credits
The Noun Project:
Check by useiconic.com
Close by Thomas Drach
N-queens problem:
OR-tools solution to the N-queens problem.
Inspired by Hakan Kjellerstrand's solution at
http://www.hakank.org/google_or_tools/,
which is licensed under the Apache License, Version 2.0:
http://www.apache.org/licenses/LICENSE-2.0
https://developers.google.com/optimization/puzzles/queens#python
for more tips

follow me on twitter and slideshare

Codeware

  • 1.
  • 2.
    your slides arenot your IDE
  • 3.
    $> not yourconsole either
  • 4.
    here are fiverules for presenting code
  • 5.
    rule 1: $ usemonospaced font $
  • 6.
  • 7.
  • 8.
    var power =function(base, exponent) { var result = 1; for (var count = 0; count < exponent; count++) result *= base; return result; }; var power = function(base, exponent) { var result = 1; for (var count = 0; count < exponent; count++) result *= base; return result; }; monospace proportional
  • 9.
    var power =function(base, exponent) { var result = 1; for (var count = 0; count < exponent; count++) result *= base; return result; }; var power = function(base, exponent) { var result = 1; for (var count = 0; count < exponent; count++) result *= base; return result; }; monospace proportional
  • 10.
    monospace monospaced fonts have betterreadability when presenting code proportional
  • 11.
    monospace proportional it isharder to follow code with proportional fonts monospaced fonts have better readability when presenting code
  • 12.
    use monospaced fonts forcode readability
  • 13.
    rule 2: $ usebig fonts $
  • 14.
    presenting for abig audience? $ this is not your desktop monitor $ font size should be bigger $
  • 15.
  • 16.
    I really meanBIGGER
 than your think
  • 17.
  • 18.
  • 19.
  • 20.
  • 21.
    BIGGER is betterhowdo you expect people in the back to read this?
  • 22.
    rule 3: $ smartsyntax
 highlighting $
  • 23.
    this is notyour IDE use syntax highlighting only where needed
  • 24.
    this is notyour IDE use syntax highlighting only where needed
  • 25.
    Presenting code onyour slides usually results in a wall of text. Highlight only the
 specific parts you want your audience to focus on.
  • 26.
    Presenting code onyour slides usually results in a wall of text. Highlight only the
 specific parts you want your audience to focus on.
  • 27.
    Presenting code onyour slides usually results in a wall of text. Highlight only the
 specific parts you want your audience to focus on.
  • 28.
    3 slides example- Ruby map function 1 2 3
  • 29.
    names = ['rey','fin', 'poe'] names.map! {|name| name.capitalize } puts names 3 slides example - Ruby map function 1 2 3
  • 30.
    names = ['rey','fin', 'poe'] names.map! {|name| name.capitalize } puts names 3 slides example - Ruby map function 1 2 3
  • 31.
    names = ['rey','fin', 'poe'] names.map! {|name| name.capitalize } puts names # output Rey Fin Poe 3 slides example - Ruby map function 1 2 3
  • 32.
    rule 4: $ usingellipsis… $
  • 33.
    import sys from ortools.constraint_solverimport pywrapcp # By default, solve the 8x8 problem. n = 8 if len(sys.argv) < 2 else int(sys.argv[1]) # Creates the solver. solver = pywrapcp.Solver("n-queens") # Creates the variables. # The array index is the row, and the value is the column. queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)] # Creates the constraints. # All columns must be different. # (The "not on the same row" constraint is implicit from the array we're # using to store our variables; since no two elements of an array # can have the same index, there can be no queens with the same row.) solver.Add(solver.AllDifferent(queens)) # No two queens can be on the same diagonal. solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)])) solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)])) db = solver.Phase(queens, solver.CHOOSE_MIN_SIZE_LOWEST_MAX, solver.ASSIGN_CENTER_VALUE) solver.NewSearch(db) # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() print print "Solutions found:", num_solutions print "Time:", solver.WallTime(), "ms" Solving the N-queens Problem
  • 34.
    import sys from ortools.constraint_solverimport pywrapcp # By default, solve the 8x8 problem. n = 8 if len(sys.argv) < 2 else int(sys.argv[1]) # Creates the solver. solver = pywrapcp.Solver("n-queens") # Creates the variables. # The array index is the row, and the value is the column. queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)] # Creates the constraints. # All columns must be different. # (The "not on the same row" constraint is implicit from the array we're # using to store our variables; since no two elements of an array # can have the same index, there can be no queens with the same row.) solver.Add(solver.AllDifferent(queens)) # No two queens can be on the same diagonal. solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)])) solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)])) db = solver.Phase(queens, solver.CHOOSE_MIN_SIZE_LOWEST_MAX, solver.ASSIGN_CENTER_VALUE) solver.NewSearch(db) # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() print print "Solutions found:", num_solutions print "Time:", solver.WallTime(), "ms" Solving the N-queens Problem what’s the point in presenting all you code if people can’t follow?
  • 35.
    import sys from ortools.constraint_solverimport pywrapcp # By default, solve the 8x8 problem. n = 8 if len(sys.argv) < 2 else int(sys.argv[1]) # Creates the solver. solver = pywrapcp.Solver("n-queens") # Creates the variables. # The array index is the row, and the value is the column. queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)] # Creates the constraints. # All columns must be different. # (The "not on the same row" constraint is implicit from the array we're # using to store our variables; since no two elements of an array # can have the same index, there can be no queens with the same row.) solver.Add(solver.AllDifferent(queens)) # No two queens can be on the same diagonal. solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)])) solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)])) db = solver.Phase(queens, solver.CHOOSE_MIN_SIZE_LOWEST_MAX, solver.ASSIGN_CENTER_VALUE) solver.NewSearch(db) # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() print print "Solutions found:", num_solutions print "Time:", solver.WallTime(), "ms" Solving the N-queens Problem keep just the relevant code
  • 36.
    import sys from ortools.constraint_solverimport pywrapcp # By default, solve the 8x8 problem. n = 8 if len(sys.argv) < 2 else int(sys.argv[1]) # Creates the solver. solver = pywrapcp.Solver("n-queens") # Creates the variables. # The array index is the row, and the value is the column. queens = [solver.IntVar(0, n - 1, "x%i" % i) for i in range(n)] # Creates the constraints. # All columns must be different. # (The "not on the same row" constraint is implicit from the array we're # using to store our variables; since no two elements of an array # can have the same index, there can be no queens with the same row.) solver.Add(solver.AllDifferent(queens)) # No two queens can be on the same diagonal. solver.Add(solver.AllDifferent([queens[i] + i for i in range(n)])) solver.Add(solver.AllDifferent([queens[i] - i for i in range(n)])) db = solver.Phase(queens, solver.CHOOSE_MIN_SIZE_LOWEST_MAX, solver.ASSIGN_CENTER_VALUE) solver.NewSearch(db) # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() print print "Solutions found:", num_solutions print "Time:", solver.WallTime(), "ms" Solving the N-queens Problem use ellipsis…
  • 37.
    ... # Creates thesolver. solver = pywrapcp.Solver("n-queens") ... # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() ... Solving the N-queens Problem
  • 38.
    ... # Creates thesolver. solver = pywrapcp.Solver("n-queens") ... # Iterates through the solutions, displaying each. num_solutions = 0 while solver.NextSolution(): queen_columns = [int(queens[i].Value()) for i in range(n)] # Displays the solution just computed. for i in range(n): for j in range(n): if queen_columns[i] == j: print "Q", else: print "_", print print num_solutions += 1 solver.EndSearch() ... Solving the N-queens Problem the focus is now on the algorithm
 not the boilerplate
  • 39.
    rule 5: $ usescreen annotation $
  • 40.
    do you wantto focus your audience’s attention on a specific area in the screen?
  • 41.
    thinking of usinga laser pointer?
  • 42.
    do you expectyour audience to track this?
  • 43.
    always create slidesas if you are the person sitting
 in the last row of the conference hall. use screen annotations.
  • 44.
    always create slidesas if you are the person sitting
 in the last row of the conference hall. use screen annotations.
  • 45.
    always create slidesas if you are the person sitting
 in the last row of the conference hall. use screen annotations.
  • 46.
    always create slidesas if you are the person sitting
 in the last row of the conference hall. use screen annotations.
  • 47.
    putting it alltogether $ ECMAScript 2015 Promise example $
  • 48.
    putting it alltogether $ ECMAScript 2015 Promise example $ the next slides will introduce the
 ECMAScript 2015 Promise Object
  • 49.
    fetchGraphData(graphName, function(error, graphData)){ if (error) { // handle error } // ... renderGraph(graphData, function(error)) { if (error) { // handle error } // ... notifyClients(msg, result, function(error, response)) { if (error) { // handle error } // ... }); }); }); Typical JS code results with
 many nested callbacks
  • 50.
    fetchGraphData(graphName, function(error, graphData)){ if (error) { // handle error } // ... renderGraph(graphData, function(error)) { if (error) { // handle error } // ... notifyClients(msg, result, function(error, response)) { if (error) { // handle error } // ... }); }); }); makes it hard to follow
  • 51.
    fetchGraphData(graphName, function(error, graphData)){ if (error) { // handle error } // ... renderGraph(graphData, function(error)) { if (error) { // handle error } // ... notifyClients(msg, result, function(error, response)) { if (error) { // handle error } // ... }); }); }); error handling is duplicated
  • 52.
  • 53.
    function fetchGraphData(graphName) { returnnew Promise(function(resolve, reject)) { let request = new XMLHttpRequest(); ...
 // XMLHttpRequest to server request.open(‘GET’, ‘http://example.com', true); request.onload = function() { if (request.status == 200) { resolve(request.response); } else { reject(new Error(request.status)); } }; }); The Promise object is used for deferred and asynchronous computations
  • 54.
    function fetchGraphData(graphName) { returnnew Promise(function(resolve, reject)) { let request = new XMLHttpRequest(); ...
 // XMLHttpRequest to server request.open(‘GET’, ‘http://example.com', true); request.onload = function() { if (request.status == 200) { resolve(request.response); } else { reject(new Error(request.status)); } }; }); resolve is called once operation has completed successfully
  • 55.
    function fetchGraphData(graphName) { returnnew Promise(function(resolve, reject)) { let request = new XMLHttpRequest(); ...
 // XMLHttpRequest to server request.open(‘GET’, ‘http://example.com', true); request.onload = function() { if (request.status == 200) { resolve(request.response); } else { reject(new Error(request.status)); } }; }); reject is called if the operation has been rejected
  • 56.
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  • 60.
    1 codeware - 5rules 2 3 4 5
  • 61.
    codeware - 5rules 2 3 4 5 monospaced font
  • 62.
    codeware - 5rules 3 4 5 monospaced font BIG
  • 63.
    codeware - 5rules 4 5 monospaced font BIG smart syntax
 highlighting
  • 64.
    codeware - 5rules 5 monospaced font BIG smart syntax highlighting ellipsis...
  • 65.
    monospaced font codeware - 5rules BIG smart syntax highlighting ellipsis... screen annotation
  • 66.
    Credits The Noun Project: Checkby useiconic.com Close by Thomas Drach N-queens problem: OR-tools solution to the N-queens problem. Inspired by Hakan Kjellerstrand's solution at http://www.hakank.org/google_or_tools/, which is licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0 https://developers.google.com/optimization/puzzles/queens#python
  • 67.
    for more tips
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