mi n i ma l i s t i c t y p e d L u a i s h e r - - PowerPoint PPT Presentation

mi n i ma l i s t i c t y p e d L u a i s h e r e

H i s h a m Mu h a mma d

< h i s h a m@k

• n

g h q . c

• m>

mi n i ma l i s t i c e x p e r i me n t a l e me r g i n g

mi n i ma l i s t i c e x p e r i me n t a l e me r g i n g

u n t y p e d : n

• t

y p e s a t a l l

a s s e mb l y , u n ( i ) t y p e d l a mb d a c a l c u l u s

t y p e d : t y p e s e x i s t !

s t r i n g a n d n u mb e r a r e d i fg e r e n t t h i n g s

( e v e n i f y

• u

c a n d

• "

1 " + 2 )

d y n a mi c a l l y t y p e d : v a l u e s h a v e t y p e s , v a r i a b l e s d

• n

' t

L u a , S c h e me , J a v a S c r i p t , P y t h

• n

, R u b y , P H P , e t c .

s t a t i c a l l y t y p e d : v a l u e s h a v e t y p e s , v a r i a b l e s h a v e t y p e s

C , J a v a , G

• ,

C # , R u s t , H a s k e l l , e t c .

P y t h

• n

→ my p y , p y t y p e R u b y → S

• r

b e t P H P → H a c k J a v a S c r i p t → T y p e S c r i p t R a c k e t → T y p e d R a c k e t e t c .

L u a ?

a d d i n g t y p e s (

• r

a n y t h i n g ! ) ma k e s a l a n g u a g e l a r g e r

• c
• n

c e p t u a l l y

• a

n d i n i mp l e me n t a t i

• n

a d d i n g t y p e s (

• r

a n y t h i n g ! ) ma k e s a l a n g u a g e l a r g e r

• c
• n

c e p t u a l l y

• a

n d i n i mp l e me n t a t i

• n

a d d i n g t y p e s (

• r

a n y t h i n g ! ) ma k e s a l a n g u a g e l a r g e r

• c
• n

c e p t u a l l y

• a

n d i n i mp l e me n t a t i

• n

i f t h e l a n g u a g e g r

• ws

t

• mu

c h , i t d

• e

s n ' t f e e l l i k e L u a a n y mo r e

i f t h e l a n g u a g e g r

• ws

t

• mu

c h , i t d

• e

s n ' t f e e l l i k e L u a a n y mo r e i f t h e t y p e c h e c k e r i s t

• s

i mp l i s t i c , i t d

• e

s n ' t f e e l l i k e L u a a n y mo r e

b u t we w a n t b

• t

h :

a s ma l l l a n g u a g e t h a t fj t s i n y

• u

r h e a d a t y p e c h e c k e r t h a t c a t c h e s wh e n y

• u

ma k e a s i l l y t y p

t h e c h a l l e n g e : t

• fj

n d t h e s we e t s p

• t

b e t we e n mi n i ma l i s m a n d f u n c t i

• n

a l i t y

t l

mi n i ma l i mp l e me n t a t i

• n

i n t h e L u a s p i r i t : L u a : 2 9 7 k B t a r b a l l p u r e s t a n d a r d C , n

• d

e p e n d e n c i e s t l : s i n g l e fj l e , c u r r e n t l y 4 8 6 l i n e s p u r e L u a , n

• d

e p e n d e n c i e s

n

• d

e p e n d e n c i e s : d r

• p

t l . l u a i n y

• u

r L u a p r

• j

e c t a n d

• fg

y

• u

g

tl check file.tl → tl gen file.tl → file.lua tl run file.tl

t wo mo d e s : . t l ( " s t r i c t " mo d e ) . l u a ( " l a x " mo d e )

function f(x) return x end local z = f(0)

function f(x: number): number return x end local z = f(0)

t l r e p

• r

t s e r r

• r

s a n d u n k n

• wn

s s e p a r a t e l y

t y p e c h e c k e r : t h e b u l k

• f

t h e c

• mp

i l e r

function keys(t: {string: string}): {string} local ks = {} for k, v in pairs(t) do table.insert(ks, k) end return ks end

t y p e s

• f

t a b l e s

wh a t i s a L u a t a b l e ?

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

t a b l e s i n t l : ma p s , l i k e {string:boolean} a r r a y , l i k e {string} r e c

• r

d , l i k e Point a r r a y

• r

e c

• r

d , l i k e Node a r r a y

• ma

p ? n

• t

y e t

n

• mi

n a l r e c

• r

d s Point = record x: number

y: number

end

n

• i

n h e r i t a n c e

• r

i n t e r f a c e s / t r a i t s ( f

• r

n

• w?

)

wi t h d y n a mi c t y p e s , i t ' s t r i v i a l t

• wr

i t e v e r y g e n e r i c c

• d

e

function keys(t: {`K: `V}): {`K} local ks = {} for k, v in pairs(t) do table.insert(ks, k) end return ks end

p r i

• r

i t i z i n g p r a c t i c a l n e e d s

• v

e r a f e a t u r e c h e c k l i s t

y a y , t y p e s ! n

• w

wh a t ?

wh i c h e r r

• r

s a r e l e f t ?

• ops.lua:279: attempt to index a nil value (field '?')

stack traceback:

• ops.lua:279: in function 'oh_no'
• ops.lua:12: in function 'not_again'
• ops.lua:490: in function 'main'

[C]: in ?

t l ( a n d L u a ) : a n y v a r i a b l e ma y b e n i l

• p

t i

• n

t y p e s ? Maybe i n H a s k e l l , Result i n R u s t , e t c . . .

t r i c k i e r f

• r

L u a : e v e r y t[x] r e t u r n s a n

• p

t i

• n

t y p e ? n a h

. . . h a v e t h e c

• mp

i l e r d e t e c t i t ?

d u g

• u

t

• f

t h e r a b b i t h

• l

e !

. . . b y t h e F O S D E M d e a d l i n e a n d b y u s e r f e e d b a c k !

i

p r a c t i c a l i s s u e s !

d e fj n i t i

• n

fj l e s require("socket") wh e n t y p e c h e c k i n g , l

• a

d socket.d.tl wh e n r u n n i n g , l

• a

d socket.lua

L u a h a s n

• f

u n c t i

• n
• v

e r l

• a

d i n g ! b u t i t ' s c

• mmo

n t

• f

a k e i t

c h a l l e n g e :

love.graphics.print({{1,1,1,1}, "Hello", {1,0,0,1}, " World"})

wh a t i s t h e t y p e

• f

coloredtext?

wh a t i s t h e t y p e

• f

coloredtext? 1 . any

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any}

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}}

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}} 5 . {[i%2==1]:{number},[i%2==0]:string}

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}} 5 . {[i%2==1]:{number},[i%2==0]:string} 6 . {[i%2==1]:({number}|len==4), [i%2==0]:string}

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}} 5 . {[i%2==1]:{number},[i%2==0]:string} 6 . {[i%2==1]:({number}|len==4), [i%2==0]:string} 7 . ({[i%2==1]:({number}|len==4), [i%2==0]:string}|len%2==0)

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}} 5 . {[i%2==1]:{number},[i%2==0]:string} 6 . {[i%2==1]:({number}|len==4), [i%2==0]:string} 7 . ({[i%2==1]:({number}|len==4), [i%2==0]:string}|len%2==0) 8 . ({[i%2==1]:({[0-1]}|len==4), [i%2==0]:string}|len%2==0)

wh a t i s t h e t y p e

• f

coloredtext? 1 . any 2 . table 3 . {any} 4 . {string or {number}} 5 . {[i%2==1]:{number},[i%2==0]:string} 6 . {[i%2==1]:({number}|len==4), [i%2==0]:string} 7 . ({[i%2==1]:({number}|len==4), [i%2==0]:string}|len%2==0) 8 . ({[i%2==1]:({[0-1]}|len==4), [i%2==0]:string}|len%2==0)

local ColorText = record r: number g: number b: number a: number text: string end function my_typed_print(colortext: {ColorText})

• - ...

end my_typed_print({ {r = 1, g = 1, b = 1, a = 1, text = "Hello"}, {r = 1, g = 0, b = 0, a = 0, text = " World"} })

t y p e s i n L u a — d i d t h e y d e l i v e r ? i s i t e a s i e r t

• ma

i n t a i n a n a p p l i c a t i

• n

?

t y p e s i n L u a — d i d t h e y d e l i v e r ? i s i t e a s i e r t

• ma

i n t a i n a n a p p l i c a t i

• n

? Y E S !

s

• ,

i n c l

• s

i n g

h t t p : / / g i t h u b . c

• m/

h i s h a mh m/ t l r e l e a s e . 1 . luarocks install tl ( s t i l l l

• k

i n g f

• r

a b e t t e r n a me ! )

L u a a n d t y p e s : j

• i

n u s ! t h a n k y

• u