292 lines
8.3 KiB
Idris
292 lines
8.3 KiB
Idris
module Quox.Parser.Lexer
|
||
|
||
import Quox.CharExtra
|
||
import Quox.Name
|
||
import Data.String.Extra
|
||
import Data.SortedMap
|
||
import public Data.String -- for singleton to reduce in IsReserved
|
||
import public Data.List.Elem
|
||
import public Text.Lexer
|
||
import public Text.Lexer.Tokenizer
|
||
import Derive.Prelude
|
||
%hide TT.Name
|
||
|
||
|
||
%default total
|
||
%language ElabReflection
|
||
|
||
|
||
||| @ Reserved reserved token
|
||
||| @ Name name, possibly qualified
|
||
||| @ Nat nat literal
|
||
||| @ Str string literal
|
||
||| @ Tag tag literal
|
||
||| @ TYPE "Type" or "★" with ascii nat directly after
|
||
||| @ Sup superscript or ^ number (displacement, or universe for ★)
|
||
public export
|
||
data Token =
|
||
Reserved String
|
||
| Name PName
|
||
| Nat Nat
|
||
| Str String
|
||
| Tag String
|
||
| TYPE Nat
|
||
| Sup Nat
|
||
%runElab derive "Token" [Eq, Ord, Show]
|
||
|
||
||| token or whitespace
|
||
||| @ Skip whitespace, comments, etc
|
||
||| @ Invalid a token which failed a post-lexer check
|
||
||| (e.g. a qualified name containing a keyword)
|
||
||| @ T a well formed token
|
||
public export
|
||
data ExtToken = Skip | Invalid String String | T Token
|
||
%runElab derive "ExtToken" [Eq, Ord, Show]
|
||
|
||
|
||
public export
|
||
data ErrorReason =
|
||
NoRuleApply
|
||
| ComposeNotClosing (Int, Int) (Int, Int)
|
||
| Other String
|
||
%runElab derive "ErrorReason" [Eq, Ord, Show]
|
||
|
||
public export
|
||
record Error where
|
||
constructor Err
|
||
reason : ErrorReason
|
||
line, col : Int
|
||
||| `Nothing` if the error is at the end of the input
|
||
char : Maybe Char
|
||
%runElab derive "StopReason" [Eq, Ord, Show]
|
||
%runElab derive "Error" [Eq, Ord, Show]
|
||
|
||
|
||
private
|
||
skip : Lexer -> Tokenizer ExtToken
|
||
skip t = match t $ const Skip
|
||
|
||
private
|
||
tmatch : Lexer -> (String -> Token) -> Tokenizer ExtToken
|
||
tmatch t f = match t (T . f)
|
||
|
||
|
||
||| [todo] escapes other than `\"` and (accidentally) `\\`
|
||
export
|
||
fromStringLit : String -> String
|
||
fromStringLit = pack . go . unpack . drop 1 . dropLast 1 where
|
||
go : List Char -> List Char
|
||
go [] = []
|
||
go ['\\'] = ['\\'] -- i guess???
|
||
go ('\\' :: c :: cs) = c :: go cs
|
||
go (c :: cs) = c :: go cs
|
||
|
||
private
|
||
string : Tokenizer ExtToken
|
||
string = tmatch stringLit (Str . fromStringLit)
|
||
|
||
private
|
||
nat : Tokenizer ExtToken
|
||
nat = tmatch (some (range '0' '9')) (Nat . cast)
|
||
|
||
private
|
||
tag : Tokenizer ExtToken
|
||
tag = tmatch (is '\'' <+> name) (Tag . drop 1)
|
||
<|> tmatch (is '\'' <+> stringLit) (Tag . fromStringLit . drop 1)
|
||
|
||
|
||
|
||
private %inline
|
||
fromSub : Char -> Char
|
||
fromSub c = case c of
|
||
'₀' => '0'; '₁' => '1'; '₂' => '2'; '₃' => '3'; '₄' => '4'
|
||
'₅' => '5'; '₆' => '6'; '₇' => '7'; '₈' => '8'; '₉' => '9'; _ => c
|
||
|
||
private %inline
|
||
fromSup : Char -> Char
|
||
fromSup c = case c of
|
||
'⁰' => '0'; '¹' => '1'; '²' => '2'; '³' => '3'; '⁴' => '4'
|
||
'⁵' => '5'; '⁶' => '6'; '⁷' => '7'; '⁸' => '8'; '⁹' => '9'; _ => c
|
||
|
||
private %inline
|
||
subToNat : String -> Nat
|
||
subToNat = cast . pack . map fromSub . unpack
|
||
|
||
private %inline
|
||
supToNat : String -> Nat
|
||
supToNat = cast . pack . map fromSup . unpack
|
||
|
||
-- ★0, Type0. base ★/Type is a Reserved
|
||
private
|
||
universe : Tokenizer ExtToken
|
||
universe = universeWith "★" <|> universeWith "Type" where
|
||
universeWith : String -> Tokenizer ExtToken
|
||
universeWith pfx =
|
||
let len = length pfx in
|
||
tmatch (exact pfx <+> digits) (TYPE . cast . drop len)
|
||
|
||
private
|
||
sup : Tokenizer ExtToken
|
||
sup = tmatch (some $ pred isSupDigit) (Sup . supToNat)
|
||
<|> tmatch (is '^' <+> digits) (Sup . cast . drop 1)
|
||
|
||
|
||
private %inline
|
||
choice : (xs : List (Tokenizer a)) -> (0 _ : NonEmpty xs) => Tokenizer a
|
||
choice (t :: ts) = foldl (\a, b => a <|> b) t ts
|
||
|
||
|
||
namespace Reserved
|
||
||| description of a reserved symbol
|
||
||| @ Word a reserved word (must not be followed by letters, digits, etc)
|
||
||| @ Sym a reserved symbol (must not be followed by symbolic chars)
|
||
||| @ Punc a character that doesn't show up in names (brackets, etc);
|
||
||| also a sequence ending in one of those, like `#[`, since the
|
||
||| difference relates to lookahead
|
||
public export
|
||
data Reserved1 = Word String | Sym String | Punc String
|
||
%runElab derive "Reserved1" [Eq, Ord, Show]
|
||
|
||
||| description of a token that might have unicode & ascii-only aliases
|
||
public export
|
||
data Reserved = Only Reserved1 | Or Reserved1 Reserved1
|
||
%runElab derive "Reserved" [Eq, Ord, Show]
|
||
|
||
public export
|
||
Sym1, Word1, Punc1 : String -> Reserved
|
||
Sym1 = Only . Sym
|
||
Word1 = Only . Word
|
||
Punc1 = Only . Punc
|
||
|
||
public export
|
||
resString1 : Reserved1 -> String
|
||
resString1 (Punc x) = x
|
||
resString1 (Word w) = w
|
||
resString1 (Sym s) = s
|
||
|
||
||| return the representative string for a token description. if there are
|
||
||| two, then it's the first one, which should be the full-unicode one
|
||
public export
|
||
resString : Reserved -> String
|
||
resString (Only r) = resString1 r
|
||
resString (r `Or` _) = resString1 r
|
||
|
||
||| return both representative strings for a token description
|
||
public export
|
||
resString2 : Reserved -> List String
|
||
resString2 (Only r) = [resString1 r]
|
||
resString2 (r `Or` s) = [resString1 r, resString1 s]
|
||
|
||
private
|
||
resTokenizer1 : Reserved1 -> String -> Tokenizer ExtToken
|
||
resTokenizer1 r str =
|
||
let res : String -> Token := const $ Reserved str in
|
||
case r of Word w => tmatch (exact w <+> reject idContEnd) res
|
||
Sym s => tmatch (exact s <+> reject symCont) res
|
||
Punc x => tmatch (exact x) res
|
||
|
||
||| match a reserved token
|
||
export
|
||
resTokenizer : Reserved -> Tokenizer ExtToken
|
||
resTokenizer (Only r) = resTokenizer1 r (resString1 r)
|
||
resTokenizer (r `Or` s) =
|
||
resTokenizer1 r (resString1 r) <|> resTokenizer1 s (resString1 r)
|
||
|
||
||| reserved words & symbols.
|
||
||| the tokens recognised by ``a `Or` b`` will be `Reserved a`.
|
||
||| e.g. `=>` in the input (if not part of a longer name)
|
||
||| will be returned as `Reserved "⇒"`.
|
||
public export
|
||
reserved : List Reserved
|
||
reserved =
|
||
[Punc1 "(", Punc1 ")", Punc1 "[", Punc1 "]", Punc1 "{", Punc1 "}",
|
||
Punc1 ",", Punc1 ";", Punc1 "#[",
|
||
Sym1 "@",
|
||
Sym1 ":",
|
||
Sym "⇒" `Or` Sym "=>",
|
||
Sym "→" `Or` Sym "->",
|
||
Sym "×" `Or` Sym "**",
|
||
Sym "≡" `Or` Sym "==",
|
||
Sym "∷" `Or` Sym "::",
|
||
Punc1 ".",
|
||
Word1 "case",
|
||
Word1 "case0", Word1 "case1",
|
||
Word "caseω" `Or` Word "case#",
|
||
Word1 "return",
|
||
Word1 "of",
|
||
Word1 "fst", Word1 "snd",
|
||
Word1 "_",
|
||
Word1 "Eq",
|
||
Word "λ" `Or` Word "fun",
|
||
Word "δ" `Or` Word "dfun",
|
||
Word "ω" `Or` Sym "#",
|
||
Sym "★" `Or` Word "Type",
|
||
Word "ℕ" `Or` Word "Nat",
|
||
Word1 "IOState",
|
||
Word1 "String",
|
||
Word1 "zero", Word1 "succ",
|
||
Word1 "coe", Word1 "comp",
|
||
Word1 "def",
|
||
Word1 "def0",
|
||
Word "defω" `Or` Word "def#",
|
||
Word1 "postulate",
|
||
Word1 "postulate0",
|
||
Word "postulateω" `Or` Word "postulate#",
|
||
Sym1 "=",
|
||
Word1 "load",
|
||
Word1 "namespace"]
|
||
|
||
public export
|
||
reservedStrings : List String
|
||
reservedStrings = map resString reserved
|
||
|
||
public export
|
||
allReservedStrings : List String
|
||
allReservedStrings = foldMap resString2 reserved
|
||
|
||
||| `IsReserved str` is true if `Reserved str` might actually show up in
|
||
||| the token stream
|
||
public export
|
||
IsReserved : String -> Type
|
||
IsReserved str = So (str `elem` allReservedStrings)
|
||
|
||
private
|
||
name : Tokenizer ExtToken
|
||
name =
|
||
match name $ \str =>
|
||
let parts = split (== '.') $ normalizeNfc str in
|
||
case find (`elem` allReservedStrings) (toList parts) of
|
||
Nothing => T $ Name $ fromListP parts
|
||
Just w => Invalid "reserved word '\{w}' inside name \{str}" str
|
||
|
||
export
|
||
tokens : Tokenizer ExtToken
|
||
tokens = choice $
|
||
map skip [pred isWhitespace,
|
||
lineComment (exact "--" <+> reject symCont),
|
||
blockComment (exact "{-") (exact "-}")] <+>
|
||
[universe] <+> -- ★ᵢ takes precedence over bare ★
|
||
map resTokenizer reserved <+>
|
||
[sup, nat, string, tag, name]
|
||
|
||
export
|
||
check : Alternative f =>
|
||
WithBounds ExtToken -> Either Error (f (WithBounds Token))
|
||
check (MkBounded val irr bounds@(MkBounds line col _ _)) = case val of
|
||
Skip => Right empty
|
||
T tok => Right $ pure $ MkBounded tok irr bounds
|
||
Invalid msg tok => Left $ Err (Other msg) line col (index 0 tok)
|
||
|
||
export
|
||
toErrorReason : StopReason -> Maybe ErrorReason
|
||
toErrorReason EndInput = Nothing
|
||
toErrorReason NoRuleApply = Just NoRuleApply
|
||
toErrorReason (ComposeNotClosing s e) = Just $ ComposeNotClosing s e
|
||
|
||
export
|
||
lex : String -> Either Error (List (WithBounds Token))
|
||
lex str =
|
||
let (res, reason, line, col, str) = lex tokens str in
|
||
case toErrorReason reason of
|
||
Nothing => concatMap check res @{MonoidApplicative}
|
||
Just e => Left $ Err {reason = e, line, col, char = index 0 str}
|