SEMANTICS.md

Semantics

This page is a first try at describing the semantics of Hedy. Because Hedy code is transpiled into Python, we define the semantics of an Hedy program in terms of the semantics of the resulting Python code, or, in case of an error, the resulting HedyException.

Level 1

Commands and types

Level 1 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	'right' + integer | 'left' + integer | empty
echo	integer | string | empty

Correct Programs

Hedy	Python
print x y	print('x y')
forward	t = turtle.Turtle() t.forward(50)
forward 100	t = turtle.Turtle() t.forward(100)
turn	t = turtle.Turtle() t.right(90)
turn left	t = turtle.Turtle() t.left(90)
turn right	t = turtle.Turtle() t.right(90)
turn 100	t = turtle.Turtle() t.right(100)
ask x	answer = input('x')
ask x echo y	answer = input('x') print('y', answer)

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
ask	Incomplete Exception
(forward | turn) text	Invalid Argument Type Exception
(not (print | ask | forward | turn | echo)) (any text)?	Invalid Exception
any valid line(s) of code not using ask echo x	Lonely Echo
_SPACE (print | ask | forward | turn | echo) (any text)?	Invalid space

Level 2

Commands and types

Level 2 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer

Correct Programs

Hedy	Python
print x y	print('x y')
forward	t = turtle.Turtle() t.forward(50)
forward 100	t = turtle.Turtle() t.forward(100)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 100	t = turtle.Turtle() t.right(100)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
x is 90 print x	x = '90' print(x)
x is ask y print x	x = input('y') print(x)
sleep	time.sleep(1)
sleep 1	time.sleep(1)

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
ask	Incomplete Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception

Level 3

Commands and types

Level 3 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list

Correct Programs

Hedy	Python
print x y	print('x y')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
ask x	answer = input('x')
x is ask y print x	x = input('y') print(x)
x is a, b, c (turn | forward) x at random	x = ['a', 'b', 'c'] t = turtle.Turtle() t.right(random.choice(x))
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
ask	Incomplete Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
items is (text without a comma) print items at random	Invalid Argument Type Exception

Level 4

Commands and types

Level 4 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
items is (text without a comma) print items at random	Invalid Argument Type Exception

Level 5

Commands and types

Level 5 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy print 'great' else print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 1 2 one is 1 if one in a print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name print 'found'	Invalid Argument Type Exception

Level 6

Commands and types

Level 6 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy print 'great' else print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name print 'found'	Invalid Argument Type Exception

Level 7

Commands and types

Level 7 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy print 'great' else print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
repeat 3 times print 'hello!'	for i in range(int('3')):   print(f'hello!')
n is 3 repeat n times print 'hello!'	n = '3' for i in range(int(n)):   print(f'hello!')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name print 'found'	Invalid Argument Type Exception

Level 8

Commands

Level 8 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
repeat 3 times   print 'hello!'	for i in range(int('3')):   print(f'hello!')
n is 3 repeat n times   print 'hello!'	n = '3' for i in range(int(n)):   print(f'hello!')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
repeat 3 times print 'hello!'	Invalid command (TODO: this has to be improved)

Level 9

Commands and types

Level 9 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
repeat 3 times   print 'hello!'	for i in range(int('3')):   print(f'hello!')
n is 3 repeat n times   print 'hello!'	n = '3' for i in range(int(n)):   print(f'hello!')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
repeat 3 times print 'hello!'	Invalid command (TODO: this has to be improved)

Level 10

Commands and types

Level 10 supports:

Command	Types
print	integer | string
ask	integer | string
forward	integer | empty
turn	integer | empty
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'
for	string + 'in' + list

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
forward	t = turtle.Turtle() t.forward(50)
forward 50	t = turtle.Turtle() t.forward(50)
a is 50 forward a	a = '50' t = turtle.Turtle() t.forward(a)
turn	t = turtle.Turtle() t.right(90)
turn 90	t = turtle.Turtle() t.right(90)
a is 50 turn a	a = '50' t = turtle.Turtle() t.right(a)
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
repeat 3 times   print 'hello!'	for i in range(int('3')):   print(f'hello!')
n is 3 repeat n times   print 'hello!'	n = '3' for i in range(int(n)):   print(f'hello!')
ns is 1, 2, 3 for n in ns   print n	ns = ['1', '2', '3'] for n in ns:   print(f'{n}')

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask | forward | turn)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask | forward | turn) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
(forward | turn) text	Invalid Argument Type Exception
a is text (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 (forward | turn) a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
repeat 3 times print 'hello!'	Invalid command (TODO: this has to be improved)

Level 11

Commands and types

Level 11 supports:

Command	Types
print	integer | string
ask	integer | string
is	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'
for	string + 'in' + list | string + 'in' + 'range' + integer + 'to' + integer

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{int(1) + int(1)}')
print 1 - 1	print(f'{int(1) - int(1)}')
print 1 * 1	print(f'{int(1) * int(1)}')
print 1 / 1	print(f'{int(1) / int(1)}')
a is 1 print a	a = '1' print(f'{a}')
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = ['1', '2', '3'] f = '4' a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = ['1', '2', '3'] f = '4' try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
ns is 1, 2, 3 for n in ns   print n	ns = ['1', '2', '3'] for n in ns:   print(f'{n}')
for a in range 2 to 4   a is a + 2	step = 1 if int(2) < int(4) else -1 for a in range(int(2), int(4) + step, step):   a = int(a) + int(2)

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1.0 + 1	Unsupported decimal number
print 1,0 + 1	Unsupported decimal number
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
for a in range 1 to 10 print 'hello!'	No Indentation Exception

Level 12

Commands and types

Level 12 supports:

Command	Types
print	integer | string | float
ask	integer | string | float
is | =	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'
for	string + 'in' + list | string + 'in' + 'range' + integer + 'to' + integer

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{1 + 1}')
print 1 - 1	print(f'{1 - 1}')
print 1 * 1	print(f'{1 * 1}')
print 1 / 1	print(f'{1 / 1}')
print 1.0 + 1	print(f'{1.0 / 1}')
a is 1 print a	a = 1 print(f'{a}')
a is 1.0 print a	a = 1.0 print(f'{a}')
a is 'text' print a	a = 'text' print(f'{a}')
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') try:   x = int(x) except ValueError:   x = float(x)   except ValueError:     pass print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = [1, 2, 3] f = 4 a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
ns is 1, 2, 3 for n in ns   print n	ns = [1, 2, 3] for n in ns:   print(f'{n}')
for a in range 2 to 4   a is a + 2	step = 1 if int(2) < int(4) else -1 for a in range(int(2), int(4) + step, step):   a = a + 2

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1,0 + 1	Invalid Command (TODO: this could be improved)
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
for a in range 1 to 10 print 'hello!'	No Indentation Exception

Level 13

Commands and types

Level 13 supports:

Command	Types
print	integer | string | float
ask	integer | string | float
is | =	string (before `is`) + any (after `is`)
sleep	empty | integer
at random	list
add to	list
remove from	list
if	boolean
if else	boolean
repeat	integer + 'times'
for	string + 'in' + list | string + 'in' + 'range' + integer + 'to' + integer
and	boolean (before `and`) + boolean (after `and`)
or	boolean (before `or`) + boolean (after `or`)

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{1 + 1}')
print 1 - 1	print(f'{1 - 1}')
print 1 * 1	print(f'{1 * 1}')
print 1 / 1	print(f'{1 / 1}')
print 1.0 + 1	print(f'{1.0 / 1}')
a is 1 print a	a = 1 print(f'{a}')
a is 1.0 print a	a = 1.0 print(f'{a}')
a is 'text' print a	a = 'text' print(f'{a}')
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') try:   x = int(x) except ValueError:   x = float(x)   except ValueError:     pass print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = [1, 2, 3] f = 4 a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
name is Hedy if name is hedy (or | and) name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if str(name) == str('Hedy') (or | and) str(name) == str('hedy'):   print(f'great') else:   print(f'fine')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
ns is 1, 2, 3 for n in ns   print n	ns = [1, 2, 3] for n in ns:   print(f'{n}')
for a in range 2 to 4   a is a + 2	step = 1 if int(2) < int(4) else -1 for a in range(int(2), int(4) + step, step):   a = a + 2

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1,0 + 1	Invalid Command (TODO: this could be improved)
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
for a in range 1 to 10 print 'hello!'	No Indentation Exception

Level 14

Commands

Level 14 supports:

• print
• ask
• is
• sleep
• at random
• add to
• remove from
• if
• if else
• repeat
• for

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{1 + 1}')
print 1 - 1	print(f'{1 - 1}')
print 1 * 1	print(f'{1 * 1}')
print 1 / 1	print(f'{1 / 1}')
print 1.0 + 1	print(f'{1.0 / 1}')
a is 1 print a	a = 1 print(f'{a}')
a is 1.0 print a	a = 1.0 print(f'{a}')
a is 'text' print a	a = 'text' print(f'{a}')
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') try:   x = int(x) except ValueError:   x = float(x)   except ValueError:     pass print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = [1, 2, 3] f = 4 a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
name is Hedy if name is hedy (or | and) name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if str(name) == str('Hedy') (or | and) str(name) == str('hedy'):   print(f'great') else:   print(f'fine')
a is 1 if a (< | <= | > | >= | !=) 2   print a	a = 1 if str(a).zfill(100) (< | <= | > | >= | !=) str('2').zfill(100):   print(f'{a}')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
ns is 1, 2, 3 for n in ns   print n	ns = [1, 2, 3] for n in ns:   print(f'{n}')
for a in range 2 to 4   a is a + 2	step = 1 if int(2) < int(4) else -1 for a in range(int(2), int(4) + step, step):   a = a + 2

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1,0 + 1	Invalid Command (TODO: this could be improved)
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
if '1' < 3   print 'true'	Invalid Argument Type Exception
for a in range 1 to 10 print 'hello!'	No Indentation Exception

Level 15

Commands

Level 15 supports:

• print
• ask
• is
• sleep
• at random
• add to
• remove from
• if
• if else
• repeat
• for
• while

Correct Programs

Hedy	Python
print 'x' 'y'	print('xy')
print 1 + 1	print(f'{1 + 1}')
print 1 - 1	print(f'{1 - 1}')
print 1 * 1	print(f'{1 * 1}')
print 1 / 1	print(f'{1 / 1}')
print 1.0 + 1	print(f'{1.0 / 1}')
a is 1 print a	a = 1 print(f'{a}')
a is 1.0 print a	a = 1.0 print(f'{a}')
a is 'text' print a	a = 'text' print(f'{a}')
sleep	time.sleep(1)
sleep 1	time.sleep(1)
x is ask 'y' print x	x = input('y') try:   x = int(x) except ValueError:   x = float(x)   except ValueError:     pass print(x)
x is a, b, c print x at random	x = ['a', 'b', 'c'] print(random.choice(x))
a is 1, 2, 3 f is 4 add f to a	a = [1, 2, 3] f = 4 a.append(f)
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
a is 1, 2, 3 f is 4 remove f from a	a = [1, 2, 3] f = 4 try:   a.remove(f) except:   pass
name is Hedy if name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if name == 'Hedy':   print(f'great') else:   print(f'fine')
name is Hedy if name is hedy (or | and) name is Hedy   print 'great' else   print 'fine'	naam = 'Hedy' if str(name) == str('Hedy') (or | and) str(name) == str('hedy'):   print(f'great') else:   print(f'fine')
a is 1 if a (< | <= | > | >= | !=) 2   print a	a = 1 if str(a).zfill(100) (< | <= | > | >= | !=) str('2').zfill(100):   print(f'{a}')
items is red, green selected is red if selected in items   print 'found!'	items = ['red', 'green'] selected = 'red' if selected in items:   print(f'found!')
ns is 1, 2, 3 for n in ns   print n	ns = [1, 2, 3] for n in ns:   print(f'{n}')
for a in range 2 to 4   a is a + 2	step = 1 if int(2) < int(4) else -1 for a in range(int(2), int(4) + step, step):   a = a + 2
a is 0 while a < 3   a is a + 1	a = 0 while str(a).zfill(100)<str(3).zfill(100):   a = a + 1

Incorrect Programs

Hedy	Exception
print	Incomplete Exception
print'x'	Invalid command
print 1,0 + 1	Invalid Command (TODO: this could be improved)
ask	Incomplete Exception
(ask | print) (any text without quotes around it)	Unquoted Text Exception
(not (print | ask)) (any text) (not is) (any text)?	Invalid Exception
_SPACE (print | ask) (any text)?	Invalid space
_SPACE (any text) is (any text)?	Invalid space
a is 1, 2, 3 answer is ask 'Is the number in ' a	Invalid Argument Type Exception
a is 1, 2, 3 f is 4 (add | remove) a (to | from) f	Invalid Argument Type Exception
items is 1, 2, 3 print items	Invalid Argument Type Exception
a is 'test' print a + 1	Invalid Argument Type Exception
a is 'text' one is 1 if one in a   print 'found!'	Invalid Argument Type Exception
name is 1, 2 if '1' is name   print 'found'	Invalid Argument Type Exception
if '1' < 3   print 'true'	Invalid Argument Type Exception
for a in range 1 to 10 print 'hello!'	No Indentation Exception