パーサーコンビネーターを使用したソリューションをここに投稿します。github にある agda-nplib ライブラリを使用します。コードは最適とはほど遠いですが、機能します。
module NewParser where
-- dummy
open import Data.Maybe
open import Data.Bool
-- includes
open import Data.List hiding (map)
-- ***
-- WAS PRELUDE IMPORTS
open import StringHelpers using (charToℕ; stringToℕ)
open import Data.String hiding (_==_; _++_)
open import Data.Char
open import Function
open import Data.Nat
open import Data.Unit
open import Data.Maybe
-- https://github.com/crypto-agda/agda-nplib/tree/master/lib/Text
open import Text.Parser
open import ParserHelpers
--- ****
--- Lessons Learned, this is the key:
--- (was a basic error that tyeps where too specific, generalisation not possible)
-- parseList : {A : Set} → Parser (Maybe A) → Parser (Maybe A) → ℕ → Parser (List (Maybe A))
-- converted to
-- parseList : {A : Set} → Parser A → Parser A → ℕ → Parser (List A)
-- *****
-- General ... Normal List (depth 1)
parseList : {A : Set} → Parser A → Parser A → ℕ → Parser (List A)
parseList oneMatcher manyMatcher n = ⟪ _++_ · (map toL oneMatcher) · (many n manyMatcher) ⟫
parseBracketList : {A : Set} → Parser A → Parser A → ℕ → Parser (List A)
parseBracketList oneMatcher manyMatcher n = bracket '(' (parseList oneMatcher manyMatcher n) ')'
parseCommaListConvert : {A : Set} → (List Char → A) → (Parser (List Char)) → ℕ → Parser (List A)
parseCommaListConvert convert parser = parseBracketList (⟪ convert · parser ⟫) (⟪ convert · parseOne "," *> parser ⟫)
-- For Numbers
number : Parser (List Char)
number = manyOneOf (toList "1234567890")
parseNumList : ℕ → Parser (List (Maybe ℕ))
parseNumList = parseCommaListConvert charsToℕ number
-- Nested List (depth 2)
--
parseListListNum : ℕ → Parser (List (List (Maybe ℕ)))
parseListListNum n = parseList (parseNumList n) ((parseOne ",") *> (parseNumList n)) n
parseManyLists : ℕ → Parser (List (List (Maybe ℕ)))
parseManyLists n = bracket '(' (parseListListNum n) ')'
-- Run the Parsers
--
open import MaybeEliminatorHelper
-- max number of terms is the number of characters in the string
-- this is for the termination checker
runParseList' : String → Maybe (List (Maybe ℕ))
runParseList' s = runParser (parseNumList (strLength s)) (toList s)
runParseList : String → Maybe (List ℕ)
runParseList = maybe-list-maybe-eliminate ∘ runParseList'
-- nested list
runParseNesList' : String → Maybe (List (List( Maybe ℕ)))
runParseNesList' s = runParser (parseManyLists (length (toList s))) (toList s)
runParseNesList : String → Maybe (List (List ℕ))
runParseNesList = maybe-list-list-maybe-eliminate ∘ runParseNesList'
ここに私のヘルパー関数があります：
module MaybeEliminatorHelper where
open import Data.Maybe
open import Category.Monad
open import Function
open import Data.List
open import Category.Functor
sequence-maybe : ∀ {a} {A : Set a} → List (Maybe A) → Maybe (List A)
sequence-maybe = sequence Data.Maybe.monad
join : {A : Set} → Maybe (Maybe A) → Maybe A
join m = m >>= id
where
open RawMonad Data.Maybe.monad
maybe-list-elem : {A : Set} → Maybe (List (Maybe A)) → Maybe (List A)
maybe-list-elem mlm = join (sequence-maybe <$> mlm)
where open RawFunctor functor
{-
sequence-maybe : [Maybe a] -> Maybe [a]
join :: Maybe (Maybe a) -> Maybe a
Maybe (List (List (Maybe A))
Maybe.fmap (List.fmap sequenc-maybe)
Maybe (List (Maybe (List A))
Maybe.fmap sequence-maybe
Maybe (Maybe (List (List A)))
join
Maybe (List (List A))
join . Maybe.fmap sequence-maybe . Maybe.fmap (List.fmap sequenc-maybe)
join . Maybe.fmap (sequence-maybe . List.fmap sequenc-maybe)
(short form)
-}
maybe-list-elem2 : {A : Set} → Maybe (List (List (Maybe A))) → Maybe (List (List A))
maybe-list-elem2 = join ∘ Mfmap (sequence-maybe ∘ Lfmap sequence-maybe)
where
open RawMonad Data.Maybe.monad hiding (join) renaming (_<$>_ to Mfmap)
open RawMonad Data.List.monad hiding (join) renaming (_<$>_ to Lfmap)
maybe-list-maybe-eliminate = maybe-list-elem
maybe-list-list-maybe-eliminate = maybe-list-elem2
その他のヘルパー関数:
-- ***
-- WAS PRELUDE IMPORTS
open import StringHelpers using (charToℕ; stringToℕ)
open import Data.String hiding (_==_)
open import Data.Char
open import Function
open import Data.Nat
open import Data.Unit
open import Data.Maybe
open import Text.Parser
open import Data.List
-- mini helpers
--
parseOne : String → Parser Char
parseOne = oneOf ∘ toList
strLength : String → ℕ
strLength = length ∘ toList
-- misc helpers
--
charsToℕ : List Char → Maybe ℕ
charsToℕ [] = nothing
charsToℕ xs = stringToℕ (fromList xs)
toL : ∀ {a} {A : Set a} → A → List A
toL x = x ∷ []
-- test
l : List (Maybe ℕ)
l = (just 3) ∷ (just 3) ∷ []
-- Parser Helpers Nicolas
--
isSpace : Char → Bool
isSpace = (_==_ ' ')
spaces : Parser ⊤
spaces = manySat isSpace *> pure _
-- decide if seperator before after brackets is spaces
someSpaces : Parser ⊤
someSpaces = someSat isSpace *> pure _
tok : Char → Parser ⊤
tok c = spaces *> char c *> pure _
bracket : ∀ {A} → Char → Parser A → Char → Parser A
bracket start p stop = tok start *> p <* tok stop
そしていくつかのテストケース:
tn09 : pList "12,13,,14" ≡ nothing
tn09 = refl
tn08 : pList "" ≡ nothing
tn08 = refl
tn07 : pList "12,13,14" ≡ nothing
tn07 = refl
-- not working tn06 : pList "(12,13,14,17)," ≡ nothing
-- not working tn06 = refl
tn05 : pList "aa,bb,cc" ≡ nothing
tn05 = refl
tn04 : pList "11" ≡ nothing
tn04 = refl
tn03 : pList "(11,12,13)" ≡ just (11 ∷ 12 ∷ 13 ∷ [])
tn03 = refl
-- new testcases
tn11 : pList2 "((1,2,3),(4,5,6),(7,8,9))" ≡ just ((1 ∷ 2 ∷ 3 ∷ []) ∷ (4 ∷ 5 ∷ 6 ∷ []) ∷ (7 ∷ 8 ∷ 9 ∷ []) ∷ [])
tn11 = refl
-- old testcases
p1 : pList2 "((1,2,3),(4,5,6))" ≡ just ((1 ∷ 2 ∷ 3 ∷ []) ∷ (4 ∷ 5 ∷ 6 ∷ []) ∷ [])
p1 = refl
p2 : pList2 "((1,2,3),(4,5,6),(7,8,9,10))" ≡ just ((1 ∷ 2 ∷ 3 ∷ []) ∷ (4 ∷ 5 ∷ 6 ∷ []) ∷ (7 ∷ 8 ∷ 9 ∷ 10 ∷ []) ∷ [])
p2 = refl
p3 : pList2 "((1),(2))" ≡ just ((1 ∷ []) ∷ (2 ∷ []) ∷ [])
p3 = refl
p4 : pList2 "((1,2))" ≡ just ((1 ∷ 2 ∷ []) ∷ [])
p4 = refl
コードを改善するための提案をお待ちしています。