Price fraction: Difference between revisions
→{{header|AppleScript}}: Added a functional variant.
(→{{header|AppleScript}}: Added a version taking a look-up table as a parameter.) |
(→{{header|AppleScript}}: Added a functional variant.) |
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=={{header|AppleScript}}==
===Procedural===
The task description doesn't make a lot of sense, implying that the pharmacist charges no more than 1.00 for his wares and that even whole-number prices are nudged by 0.10 and odd ones aren't. This offering takes any decimal currency value and standardises just the fractional part:
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Originals: 0.92, 0.86, 0.10, 0.40, 0.00, 0.34, 0.44, 0.77, 0.67, 0.19, 1.00, 0.02, 0.49, 0.40, 0.61, 0.91, 0.85, 0.54, 0.01, 0.04
Standardised: 0.98, 0.94, 0.18, 0.54, 0.00, 0.50, 8.00, 0.86, 0.78, 0.32, 1.00, 0.10, 0.62, 0.54, 0.74, 0.98, 0.90, 0.66, 0.10, 0.10"</lang>
===Functional===
<lang applescript>---------------------- PRICE FRACTION ----------------------
property table : [¬
{0.06, 0.1}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38}, ¬
{0.31, 0.44}, {0.36, 0.5}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62}, ¬
{0.56, 0.66}, {0.61, 0.7}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, ¬
{0.81, 0.86}, {0.86, 0.9}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.0}]
-- rescaled :: [(Float, Float)] -> Float -> Float
on rescaled(table)
script
on |λ|(x)
if 0 > x or 1.01 < x then
|Left|("Out of range.")
else
|Right|(snd(my head(dropWhile(compose(ge(x), my fst), table))))
end if
end |λ|
end script
end rescaled
--------------------------- TEST ---------------------------
on run
fTable("Price adjustments:\n", ¬
showReal(2), either(identity, showReal(2)), ¬
rescaled(table), enumFromThenTo(-0.05, 0, 1.1))
end run
----------- GENERAL AND REUSABLE PURE FUNCTIONS ------------
-- Left :: a -> Either a b
on |Left|(x)
{type:"Either", |Left|:x, |Right|:missing value}
end |Left|
-- Right :: b -> Either a b
on |Right|(x)
{type:"Either", |Left|:missing value, |Right|:x}
end |Right|
-- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
on compose(f, g)
script
property mf : mReturn(f)
property mg : mReturn(g)
on |λ|(x)
mf's |λ|(mg's |λ|(x))
end |λ|
end script
end compose
-- drop :: Int -> [a] -> [a]
-- drop :: Int -> String -> String
on drop(n, xs)
set c to class of xs
if script is not c then
if string is not c then
if n < length of xs then
items (1 + n) thru -1 of xs
else
{}
end if
else
if n < length of xs then
text (1 + n) thru -1 of xs
else
""
end if
end if
else
take(n, xs) -- consumed
return xs
end if
end drop
-- dropWhile :: (a -> Bool) -> [a] -> [a]
-- dropWhile :: (Char -> Bool) -> String -> String
on dropWhile(p, xs)
set lng to length of xs
set i to 1
tell mReturn(p)
repeat while i ≤ lng and |λ|(item i of xs)
set i to i + 1
end repeat
end tell
drop(i - 1, xs)
end dropWhile
-- either :: (a -> c) -> (b -> c) -> Either a b -> c
on either(lf, rf)
script
on |λ|(e)
if missing value is |Left| of e then
tell mReturn(rf) to |λ|(|Right| of e)
else
tell mReturn(lf) to |λ|(|Left| of e)
end if
end |λ|
end script
end either
-- enumFromThenTo :: Int -> Int -> Int -> [Int]
on enumFromThenTo(x1, x2, y)
set xs to {}
set d to x2 - x1
set v to x1
repeat until v ≥ y
set end of xs to v
set v to d + v
end repeat
return xs
end enumFromThenTo
-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
tell mReturn(f)
set v to startValue
set lng to length of xs
repeat with i from 1 to lng
set v to |λ|(v, item i of xs, i, xs)
end repeat
return v
end tell
end foldl
-- fst :: (a, b) -> a
on fst(tpl)
if class of tpl is record then
|1| of tpl
else
item 1 of tpl
end if
end fst
-- fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String
on fTable(s, xShow, fxShow, f, xs)
set ys to map(xShow, xs)
set w to maximum(map(my |length|, ys))
script arrowed
on |λ|(a, b)
justifyRight(w, space, a) & " -> " & b
end |λ|
end script
s & linefeed & unlines(zipWith(arrowed, ¬
ys, map(compose(fxShow, f), xs)))
end fTable
-- ge :: Ord a => a -> a -> Bool
on ge(a)
-- True if a is greater
-- than or equal to b.
script
on |λ|(b)
a ≥ b
end |λ|
end script
end ge
-- head :: [a] -> a
on head(xs)
if xs = {} then
missing value
else
item 1 of xs
end if
end head
-- identity :: a -> a
on identity(x)
-- The argument unchanged.
x
end identity
-- justifyLeft :: Int -> Char -> String -> String
on justifyLeft(n, cFiller, strText)
if n > length of strText then
text 1 thru n of (strText & replicate(n, cFiller))
else
strText
end if
end justifyLeft
-- justifyRight :: Int -> Char -> String -> String
on justifyRight(n, cFiller, strText)
if n > length of strText then
text -n thru -1 of ((replicate(n, cFiller) as text) & strText)
else
strText
end if
end justifyRight
-- length :: [a] -> Int
on |length|(xs)
set c to class of xs
if list is c or string is c then
length of xs
else
(2 ^ 29 - 1) -- (maxInt - simple proxy for non-finite)
end if
end |length|
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
-- The list obtained by applying f
-- to each element of xs.
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
-- max :: Ord a => a -> a -> a
on max(x, y)
if x > y then
x
else
y
end if
end max
-- maximum :: Ord a => [a] -> a
on maximum(xs)
script
on |λ|(a, b)
if a is missing value or b > a then
b
else
a
end if
end |λ|
end script
foldl(result, missing value, xs)
end maximum
-- min :: Ord a => a -> a -> a
on min(x, y)
if y < x then
y
else
x
end if
end min
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
-- 2nd class handler function lifted into 1st class script wrapper.
if script is class of f then
f
else
script
property |λ| : f
end script
end if
end mReturn
-- Egyptian multiplication - progressively doubling a list, appending
-- stages of doubling to an accumulator where needed for binary
-- assembly of a target length
-- replicate :: Int -> a -> [a]
on replicate(n, a)
set out to {}
if 1 > n then return out
set dbl to {a}
repeat while (1 < n)
if 0 < (n mod 2) then set out to out & dbl
set n to (n div 2)
set dbl to (dbl & dbl)
end repeat
return out & dbl
end replicate
-- showReal :: Num b => Int -> b -> String
on showReal(n)
script
on |λ|(x)
set {l, r} to splitOn(".", (x as real) as string)
l & "." & justifyLeft(n, "0", r)
end |λ|
end script
end showReal
-- snd :: (a, b) -> b
on snd(tpl)
if class of tpl is record then
|2| of tpl
else
item 2 of tpl
end if
end snd
-- splitOn :: String -> String -> [String]
on splitOn(pat, src)
set {dlm, my text item delimiters} to ¬
{my text item delimiters, pat}
set xs to text items of src
set my text item delimiters to dlm
return xs
end splitOn
-- str :: a -> String
on str(x)
x as text
end str
-- take :: Int -> [a] -> [a]
-- take :: Int -> String -> String
on take(n, xs)
set c to class of xs
if list is c then
if 0 < n then
items 1 thru min(n, length of xs) of xs
else
{}
end if
else if string is c then
if 0 < n then
text 1 thru min(n, length of xs) of xs
else
""
end if
else if script is c then
set ys to {}
repeat with i from 1 to n
set v to |λ|() of xs
if missing value is v then
return ys
else
set end of ys to v
end if
end repeat
return ys
else
missing value
end if
end take
-- unlines :: [String] -> String
on unlines(xs)
-- A single string formed by the intercalation
-- of a list of strings with the newline character.
set {dlm, my text item delimiters} to ¬
{my text item delimiters, linefeed}
set s to xs as text
set my text item delimiters to dlm
s
end unlines
-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
on zipWith(f, xs, ys)
set lng to min(length of xs, length of ys)
set lst to {}
if 1 > lng then
return {}
else
tell mReturn(f)
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, item i of ys)
end repeat
return lst
end tell
end if
end zipWith</lang>
{{Out}}
<pre>Price adjustments:
-0.05 -> Out of range.
0.00 -> 0.10
0.05 -> 0.10
0.10 -> 0.18
0.15 -> 0.26
0.20 -> 0.32
0.25 -> 0.38
0.30 -> 0.44
0.35 -> 0.50
0.40 -> 0.54
0.45 -> 0.58
0.50 -> 0.62
0.55 -> 0.66
0.60 -> 0.70
0.65 -> 0.74
0.70 -> 0.78
0.75 -> 0.82
0.80 -> 0.86
0.85 -> 0.90
0.90 -> 0.94
0.95 -> 0.98
1.00 -> 1.00
1.05 -> Out of range.</pre>
=={{header|AutoHotkey}}==
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