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Updated notes to reflect new rule shorthand syntax

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This commit is contained in:
Lawrence Bethlenfalvy
2022-07-06 20:18:39 +02:00
parent ec7ad81fac
commit 5d8d515c28
2 changed files with 22 additions and 22 deletions
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38
README.md
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@@ -7,14 +7,14 @@ Hello World in Orchid
```orchid ```orchid
import std::io::(println, out) import std::io::(println, out)
main = println out "Hello World!" main == println out "Hello World!"
``` ```
Basic command line calculator Basic command line calculator
```orchid ```orchid
import std::io::(readln, printf, in, out) import std::io::(readln, printf, in, out)
main = ( main == (
readln in >>= int |> \a. readln in >>= int |> \a.
readln in >>= \op. readln in >>= \op.
readln in >>= int |> \b. readln in >>= int |> \b.
@@ -31,7 +31,7 @@ Grep
```orchid ```orchid
import std::io::(readln, println, in, out, getarg) import std::io::(readln, println, in, out, getarg)
main = loop \r. ( main == loop \r. (
readln in >>= \line. readln in >>= \line.
if (substring (getarg 1) line) if (substring (getarg 1) line)
then (println out ln >>= r) then (println out ln >>= r)
@@ -41,7 +41,7 @@ main = loop \r. (
Filter through an arbitrary collection Filter through an arbitrary collection
```orchid ```orchid
filter = @C:Type -> Type. @:Map C. @T. \f:T -> Bool. \coll:C T. ( filter == @C:Type -> Type. @:Map C. @T. \f:T -> Bool. \coll:C T. (
coll >> \el. if (f el) then (Some el) else Nil coll >> \el. if (f el) then (Some el) else Nil
):(C T) ):(C T)
``` ```
@@ -122,9 +122,9 @@ types whose defaults have implmentations based on your defaults.
For a demonstration, here's a sample implementation of the Option monad. For a demonstration, here's a sample implementation of the Option monad.
```orchid ```orchid
--[[ The definition of Monad ]]-- --[[ The definition of Monad ]]--
Bind = \M:Type -> Type. @T -> @U -> (T -> M U) -> M T -> M U Bind == \M:Type -> Type. @T -> @U -> (T -> M U) -> M T -> M U
Return = \M:Type -> Type. @T -> T -> M T Return == \M:Type -> Type. @T -> T -> M T
Monad = \M:Type -> Type. ( Monad == \M:Type -> Type. (
@:Bind M. @:Bind M.
@:Return M. @:Return M.
0 --[ Note that empty expressions are forbidden so those that exist 0 --[ Note that empty expressions are forbidden so those that exist
@@ -134,19 +134,19 @@ Monad = \M:Type -> Type. (
) )
--[[ The definition of Option ]]-- --[[ The definition of Option ]]--
export Option = \T:Type. @U -> U -> (T -> U) -> U export Option == \T:Type. @U -> U -> (T -> U) -> U
--[ Constructors ]-- --[ Constructors ]--
export Some = @T. \data:T. ( \default. \map. map data ):(Option T) export Some == @T. \data:T. ( \default. \map. map data ):(Option T)
export None = @T. ( \default. \map. default ):(Option T) export None == @T. ( \default. \map. default ):(Option T)
--[ Implement Monad ]-- --[ Implement Monad ]--
default returnOption = Some:(Return Option) default returnOption == Some:(Return Option)
default bindOption = ( @T:Type. @U:Type. default bindOption == ( @T:Type. @U:Type.
\f:T -> U. \opt:Option T. opt None f \f:T -> U. \opt:Option T. opt None f
):(Bind Option) ):(Bind Option)
--[ Sample function that works on unknown monad to demonstrate HKTs. --[ Sample function that works on unknown monad to demonstrate HKTs.
Turns (Option (M T)) into (M (Option T)), "raising" the unknown monad Turns (Option (M T)) into (M (Option T)), "raising" the unknown monad
out of the Option ]-- out of the Option ]--
export raise = @M:Type -> Type. @T:Type. @:Monad M. \opt:Option (M T). ( export raise == @M:Type -> Type. @T:Type. @:Monad M. \opt:Option (M T). (
opt (return None) (\m. bind m (\x. Some x)) opt (return None) (\m. bind m (\x. Some x))
):(M (Option T)) ):(M (Option T))
``` ```
@@ -162,7 +162,7 @@ Add has three arguments, two are the types of the operands and one is
the result: the result:
```orchid ```orchid
default concatListAdd replacing applicativeAdd = @T. ( default concatListAdd replacing applicativeAdd == @T. (
... ...
):(Add (List T) (List T) (List T)) ):(Add (List T) (List T) (List T))
``` ```
@@ -170,7 +170,7 @@ default concatListAdd replacing applicativeAdd = @T. (
For completeness' sake, the original definition might look like this: For completeness' sake, the original definition might look like this:
```orchid ```orchid
default elementwiseAdd = @C:Type -> Type. @T. @U. @V. @:(Applicative C). @:(Add T U V). ( default elementwiseAdd == @C:Type -> Type. @T. @U. @V. @:(Applicative C). @:(Add T U V). (
... ...
):(Add (C T) (C U) (C V)) ):(Add (C T) (C U) (C V))
``` ```
@@ -179,7 +179,7 @@ With the use of autos, here's what the recursive multiplication
implementation looks like: implementation looks like:
```orchid ```orchid
default iterativeMultiply = @T. @:(Add T T T). ( default iterativeMultiply == @T. @:(Add T T T). (
\a:int.\b:T. loop \r. (\i. \a:int.\b:T. loop \r. (\i.
ifthenelse (ieq i 0) ifthenelse (ieq i 0)
b b
@@ -191,7 +191,7 @@ default iterativeMultiply = @T. @:(Add T T T). (
This could then be applied to any type that's closed over addition This could then be applied to any type that's closed over addition
```orchid ```orchid
aroundTheWorldLyrics = ( aroundTheWorldLyrics == (
mult 18 (add (mult 4 "Around the World\n") "\n") mult 18 (add (mult 4 "Around the World\n") "\n")
) )
``` ```
@@ -231,9 +231,9 @@ $a - $b =10=> (sub $a $b)
The recursive addition function now looks like this The recursive addition function now looks like this
```orchid ```orchid
default iterativeMultiply = @T. @:(Add T T T). ( default iterativeMultiply == @T. @:(Add T T T). (
\a:int.\b:T. loop \r. (\i. \a:int.\b:T. loop \r. (\i.
if (i == 0) then b if (i = 0) then b
else (b + (r (i - 1))) else (b + (r (i - 1)))
) a ) a
):(Multiply T int T) ):(Multiply T int T)

6
notes.md
View File

@@ -4,13 +4,13 @@
import std::io::(println, out) -- imports import std::io::(println, out) -- imports
-- single word substitution (alias) -- single word substitution (alias)
greet = \name. printf out "Hello {}!\n" [name] greet == \name. printf out "Hello {}!\n" [name]
-- multi-word exported substitution -- multi-word exported substitution with nonzero priority
export (...$pre ;) $a ...$post) =200=> (...$pre (greet $a) ...$post) export (...$pre ;) $a ...$post) =200=> (...$pre (greet $a) ...$post)
-- single-word exported substitution -- single-word exported substitution
export main = ( export main == (
print "What is your name? >> print "What is your name? >>
readln >>= \name. readln >>= \name.
greet name greet name