404 lines
17 KiB
Text
404 lines
17 KiB
Text
/-
|
||
Copyright (c) 2020 Microsoft Corporation. All rights reserved.
|
||
Released under Apache 2.0 license as described in the file LICENSE.
|
||
Authors: Leonardo de Moura
|
||
-/
|
||
import Lean.Elab.Command
|
||
import Lean.Parser.Syntax
|
||
import Lean.Elab.Util
|
||
|
||
namespace Lean.Elab.Term
|
||
/--
|
||
Expand `optional «precedence»` where
|
||
«precedence» := leading_parser " : " >> precedenceParser -/
|
||
def expandOptPrecedence (stx : Syntax) : MacroM (Option Nat) :=
|
||
if stx.isNone then
|
||
return none
|
||
else
|
||
return some (← evalPrec stx[0][1])
|
||
|
||
private def mkParserSeq (ds : Array (Term × Nat)) : TermElabM (Term × Nat) := do
|
||
if ds.size == 0 then
|
||
throwUnsupportedSyntax
|
||
else if ds.size == 1 then
|
||
pure ds[0]!
|
||
else
|
||
let mut (r, stackSum) := ds[0]!
|
||
for (d, stackSz) in ds[1:ds.size] do
|
||
r ← `(ParserDescr.binary `andthen $r $d)
|
||
stackSum := stackSum + stackSz
|
||
return (r, stackSum)
|
||
|
||
structure ToParserDescrContext where
|
||
catName : Name
|
||
first : Bool
|
||
leftRec : Bool -- true iff left recursion is allowed
|
||
/-- See comment at `Parser.ParserCategory`. -/
|
||
behavior : Parser.LeadingIdentBehavior
|
||
|
||
abbrev ToParserDescrM := ReaderT ToParserDescrContext (StateRefT (Option Nat) TermElabM)
|
||
abbrev ToParserDescr := ToParserDescrM (Term × Nat)
|
||
private def markAsTrailingParser (lhsPrec : Nat) : ToParserDescrM Unit := set (some lhsPrec)
|
||
|
||
@[inline] private def withNotFirst {α} (x : ToParserDescrM α) : ToParserDescrM α :=
|
||
withReader (fun ctx => { ctx with first := false }) x
|
||
|
||
def ensureUnaryOutput (x : Term × Nat) : Term :=
|
||
let (stx, stackSz) := x
|
||
if stackSz != 1 then
|
||
Unhygienic.run ``(ParserDescr.unary $(quote `group) $stx)
|
||
else
|
||
stx
|
||
|
||
@[inline] private def withNestedParser (x : ToParserDescr) : ToParserDescr := do
|
||
withReader (fun ctx => { ctx with leftRec := false, first := false }) x
|
||
|
||
def checkLeftRec (stx : Syntax) : ToParserDescrM Bool := do
|
||
let ctx ← read
|
||
unless ctx.first && stx.getKind == ``Lean.Parser.Syntax.cat do
|
||
return false
|
||
let cat := stx[0].getId.eraseMacroScopes
|
||
unless cat == ctx.catName do
|
||
return false
|
||
let prec? ← liftMacroM <| expandOptPrecedence stx[1]
|
||
unless ctx.leftRec do
|
||
throwErrorAt stx[3] "invalid occurrence of '{cat}', parser algorithm does not allow this form of left recursion"
|
||
markAsTrailingParser (prec?.getD 0)
|
||
return true
|
||
|
||
/-- Resolve the given parser name and return a list of candidates.
|
||
Each candidate is a pair `(resolvedParserName, isDescr)`.
|
||
`isDescr == true` if the type of `resolvedParserName` is a `ParserDescr`. -/
|
||
def resolveParserName [Monad m] [MonadInfoTree m] [MonadResolveName m] [MonadEnv m] [MonadError m] (parserName : Syntax) : m (List (Name × Bool)) := do
|
||
try
|
||
let candidates ← resolveGlobalConstWithInfos parserName
|
||
/- Convert `candidates` in a list of pairs `(c, isDescr)`, where `c` is the parser name,
|
||
and `isDescr` is true iff `c` has type `Lean.ParserDescr` or `Lean.TrailingParser` -/
|
||
let env ← getEnv
|
||
return candidates.filterMap fun c =>
|
||
match env.find? c with
|
||
| none => none
|
||
| some info =>
|
||
match info.type with
|
||
| Expr.const ``Lean.Parser.TrailingParser _ => (c, false)
|
||
| Expr.const ``Lean.Parser.Parser _ => (c, false)
|
||
| Expr.const ``Lean.ParserDescr _ => (c, true)
|
||
| Expr.const ``Lean.TrailingParserDescr _ => (c, true)
|
||
| _ => none
|
||
catch _ => return []
|
||
|
||
open TSyntax.Compat in
|
||
/--
|
||
Given a `stx` of category `syntax`, return a `(newStx, lhsPrec?)`,
|
||
where `newStx` is of category `term`. After elaboration, `newStx` should have type
|
||
`TrailingParserDescr` if `lhsPrec?.isSome`, and `ParserDescr` otherwise. -/
|
||
partial def toParserDescr (stx : Syntax) (catName : Name) : TermElabM (Term × Option Nat) := do
|
||
let env ← getEnv
|
||
let behavior := Parser.leadingIdentBehavior env catName
|
||
let ((newStx, _), lhsPrec?) ← (process stx { catName := catName, first := true, leftRec := true, behavior := behavior }).run none
|
||
return (newStx, lhsPrec?)
|
||
where
|
||
process (stx : Syntax) : ToParserDescr := withRef stx do
|
||
let kind := stx.getKind
|
||
if kind == nullKind then
|
||
processSeq stx
|
||
else if kind == choiceKind then
|
||
process stx[0]
|
||
else if kind == ``Lean.Parser.Syntax.paren then
|
||
process stx[1]
|
||
else if kind == ``Lean.Parser.Syntax.cat then
|
||
processNullaryOrCat stx
|
||
else if kind == ``Lean.Parser.Syntax.unary then
|
||
processAlias stx[0] #[stx[2]]
|
||
else if kind == ``Lean.Parser.Syntax.binary then
|
||
processAlias stx[0] #[stx[2], stx[4]]
|
||
else if kind == ``Lean.Parser.Syntax.sepBy then
|
||
processSepBy stx
|
||
else if kind == ``Lean.Parser.Syntax.sepBy1 then
|
||
processSepBy1 stx
|
||
else if kind == ``Lean.Parser.Syntax.atom then
|
||
processAtom stx
|
||
else if kind == ``Lean.Parser.Syntax.nonReserved then
|
||
processNonReserved stx
|
||
else
|
||
let stxNew? ← liftM (liftMacroM (expandMacro? stx) : TermElabM _)
|
||
match stxNew? with
|
||
| some stxNew => process stxNew
|
||
| none => throwErrorAt stx "unexpected syntax kind of category `syntax`: {kind}"
|
||
|
||
/-- Sequence (aka NullNode) -/
|
||
processSeq (stx : Syntax) := do
|
||
let args := stx.getArgs
|
||
if (← checkLeftRec stx[0]) then
|
||
if args.size == 1 then throwErrorAt stx "invalid atomic left recursive syntax"
|
||
let args := args.eraseIdx 0
|
||
let args ← args.mapM fun arg => withNestedParser do process arg
|
||
mkParserSeq args
|
||
else
|
||
let args ← args.mapIdxM fun i arg => withReader (fun ctx => { ctx with first := ctx.first && i.val == 0 }) do process arg
|
||
mkParserSeq args
|
||
|
||
ensureNoPrec (stx : Syntax) :=
|
||
unless stx[1].isNone do
|
||
throwErrorAt stx[1] "unexpected precedence"
|
||
|
||
processParserCategory (stx : Syntax) := do
|
||
let catName := stx[0].getId.eraseMacroScopes
|
||
if (← read).first && catName == (← read).catName then
|
||
throwErrorAt stx "invalid atomic left recursive syntax"
|
||
let prec? ← liftMacroM <| expandOptPrecedence stx[1]
|
||
let prec := prec?.getD 0
|
||
return (← `(ParserDescr.cat $(quote catName) $(quote prec)), 1)
|
||
|
||
processAlias (id : Syntax) (args : Array Syntax) := do
|
||
let aliasName := id.getId.eraseMacroScopes
|
||
let info ← Parser.getParserAliasInfo aliasName
|
||
let args ← args.mapM (withNestedParser ∘ process)
|
||
let (args, stackSz) := if let some stackSz := info.stackSz? then
|
||
if !info.autoGroupArgs then
|
||
(args.map (·.1), stackSz)
|
||
else
|
||
(args.map ensureUnaryOutput, stackSz)
|
||
else
|
||
let (args, stackSzs) := args.unzip
|
||
(args, stackSzs.foldl (· + ·) 0)
|
||
let stx ← match args with
|
||
| #[] => Parser.ensureConstantParserAlias aliasName; ``(ParserDescr.const $(quote aliasName))
|
||
| #[p1] => Parser.ensureUnaryParserAlias aliasName; ``(ParserDescr.unary $(quote aliasName) $p1)
|
||
| #[p1, p2] => Parser.ensureBinaryParserAlias aliasName; ``(ParserDescr.binary $(quote aliasName) $p1 $p2)
|
||
| _ => unreachable!
|
||
return (stx, stackSz)
|
||
|
||
processNullaryOrCat (stx : Syntax) := do
|
||
match (← resolveParserName stx[0]) with
|
||
| [(c, true)] =>
|
||
ensureNoPrec stx
|
||
-- `syntax _ :=` at least enforces this
|
||
let stackSz := 1
|
||
return (mkIdentFrom stx c, stackSz)
|
||
| [(c, false)] =>
|
||
ensureNoPrec stx
|
||
-- as usual, we assume that people using `Parser` know what they are doing
|
||
let stackSz := 1
|
||
return (← `(ParserDescr.parser $(quote c)), stackSz)
|
||
| cs@(_ :: _ :: _) => throwError "ambiguous parser declaration {cs.map (·.1)}"
|
||
| [] =>
|
||
let id := stx[0].getId.eraseMacroScopes
|
||
if Parser.isParserCategory (← getEnv) id then
|
||
processParserCategory stx
|
||
else if (← Parser.isParserAlias id) then
|
||
ensureNoPrec stx
|
||
processAlias stx[0] #[]
|
||
else
|
||
throwError "unknown parser declaration/category/alias '{id}'"
|
||
|
||
processSepBy (stx : Syntax) := do
|
||
let p ← ensureUnaryOutput <$> withNestedParser do process stx[1]
|
||
let sep := stx[3]
|
||
let psep ← if stx[4].isNone then `(ParserDescr.symbol $sep) else ensureUnaryOutput <$> withNestedParser do process stx[4][1]
|
||
let allowTrailingSep := !stx[5].isNone
|
||
return (← `(ParserDescr.sepBy $p $sep $psep $(quote allowTrailingSep)), 1)
|
||
|
||
processSepBy1 (stx : Syntax) := do
|
||
let p ← ensureUnaryOutput <$> withNestedParser do process stx[1]
|
||
let sep := stx[3]
|
||
let psep ← if stx[4].isNone then `(ParserDescr.symbol $sep) else ensureUnaryOutput <$> withNestedParser do process stx[4][1]
|
||
let allowTrailingSep := !stx[5].isNone
|
||
return (← `(ParserDescr.sepBy1 $p $sep $psep $(quote allowTrailingSep)), 1)
|
||
|
||
isValidAtom (s : String) : Bool :=
|
||
!s.isEmpty &&
|
||
s.front != '\'' &&
|
||
s.front != '\"' &&
|
||
!(s.front == '`' && (s.endPos == ⟨1⟩ || isIdFirst (s.get ⟨1⟩) || isIdBeginEscape (s.get ⟨1⟩))) &&
|
||
!s.front.isDigit
|
||
|
||
processAtom (stx : Syntax) := do
|
||
match stx[0].isStrLit? with
|
||
| some atom =>
|
||
unless isValidAtom atom do
|
||
throwErrorAt stx "invalid atom"
|
||
/- For syntax categories where initialized with `LeadingIdentBehavior` different from default (e.g., `tactic`), we automatically mark
|
||
the first symbol as nonReserved. -/
|
||
if (← read).behavior != Parser.LeadingIdentBehavior.default && (← read).first then
|
||
return (← `(ParserDescr.nonReservedSymbol $(quote atom) false), 1)
|
||
else
|
||
return (← `(ParserDescr.symbol $(quote atom)), 1)
|
||
| none => throwUnsupportedSyntax
|
||
|
||
processNonReserved (stx : Syntax) := do
|
||
match stx[1].isStrLit? with
|
||
| some atom => return (← `(ParserDescr.nonReservedSymbol $(quote atom) false), 1)
|
||
| none => throwUnsupportedSyntax
|
||
|
||
|
||
end Term
|
||
|
||
namespace Command
|
||
open Lean.Syntax
|
||
open Lean.Parser.Term hiding macroArg
|
||
open Lean.Parser.Command
|
||
|
||
private def declareSyntaxCatQuotParser (catName : Name) : CommandElabM Unit := do
|
||
if let .str _ suffix := catName then
|
||
let quotSymbol := "`(" ++ suffix ++ "|"
|
||
let name := catName ++ `quot
|
||
let cmd ← `(
|
||
@[termParser] def $(mkIdent name) : Lean.ParserDescr :=
|
||
Lean.ParserDescr.node `Lean.Parser.Term.quot $(quote Lean.Parser.maxPrec)
|
||
(Lean.ParserDescr.node $(quote name) $(quote Lean.Parser.maxPrec)
|
||
(Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol $(quote quotSymbol))
|
||
(Lean.ParserDescr.binary `andthen
|
||
(Lean.ParserDescr.cat $(quote catName) 0)
|
||
(Lean.ParserDescr.symbol ")")))))
|
||
elabCommand cmd
|
||
|
||
@[builtinCommandElab syntaxCat] def elabDeclareSyntaxCat : CommandElab := fun stx => do
|
||
let catName := stx[1].getId
|
||
let catBehavior :=
|
||
if stx[2].isNone then
|
||
Parser.LeadingIdentBehavior.default
|
||
else if stx[2][3].getKind == ``Parser.Command.catBehaviorBoth then
|
||
Parser.LeadingIdentBehavior.both
|
||
else
|
||
Parser.LeadingIdentBehavior.symbol
|
||
let attrName := catName.appendAfter "Parser"
|
||
let env ← getEnv
|
||
let env ← Parser.registerParserCategory env attrName catName catBehavior
|
||
setEnv env
|
||
declareSyntaxCatQuotParser catName
|
||
|
||
/--
|
||
Auxiliary function for creating declaration names from parser descriptions.
|
||
Example:
|
||
Given
|
||
```
|
||
syntax term "+" term : term
|
||
syntax "[" sepBy(term, ", ") "]" : term
|
||
```
|
||
It generates the names `term_+_` and `term[_,]`
|
||
-/
|
||
partial def mkNameFromParserSyntax (catName : Name) (stx : Syntax) : MacroM Name := do
|
||
mkUnusedBaseName <| Name.mkSimple <| appendCatName <| visit stx ""
|
||
where
|
||
visit (stx : Syntax) (acc : String) : String :=
|
||
match stx.isStrLit? with
|
||
| some val => acc ++ (val.trim.map fun c => if c.isWhitespace then '_' else c).capitalize
|
||
| none =>
|
||
match stx with
|
||
| Syntax.node _ k args =>
|
||
if k == ``Lean.Parser.Syntax.cat then
|
||
acc ++ "_"
|
||
else
|
||
args.foldl (init := acc) fun acc arg => visit arg acc
|
||
| Syntax.ident .. => acc
|
||
| Syntax.atom .. => acc
|
||
| Syntax.missing => acc
|
||
|
||
appendCatName (str : String) :=
|
||
match catName with
|
||
| .str _ s => s ++ str
|
||
| _ => str
|
||
|
||
/-- We assume a new syntax can be treated as an atom when it starts and ends with a token.
|
||
Here are examples of atom-like syntax.
|
||
```
|
||
syntax "(" term ")" : term
|
||
syntax "[" (sepBy term ",") "]" : term
|
||
syntax "foo" : term
|
||
```
|
||
-/
|
||
private partial def isAtomLikeSyntax (stx : Syntax) : Bool :=
|
||
let kind := stx.getKind
|
||
if kind == nullKind then
|
||
isAtomLikeSyntax stx[0] && isAtomLikeSyntax stx[stx.getNumArgs - 1]
|
||
else if kind == choiceKind then
|
||
isAtomLikeSyntax stx[0] -- see toParserDescr
|
||
else if kind == ``Lean.Parser.Syntax.paren then
|
||
isAtomLikeSyntax stx[1]
|
||
else
|
||
kind == ``Lean.Parser.Syntax.atom
|
||
|
||
def resolveSyntaxKind (k : Name) : CommandElabM Name := do
|
||
checkSyntaxNodeKindAtNamespaces k (← getCurrNamespace)
|
||
<|>
|
||
throwError "invalid syntax node kind '{k}'"
|
||
|
||
@[builtinCommandElab «syntax»] def elabSyntax : CommandElab := fun stx => do
|
||
let `($[$doc?:docComment]? $[ @[ $attrInstances:attrInstance,* ] ]? $attrKind:attrKind syntax $[: $prec? ]? $[(name := $name?)]? $[(priority := $prio?)]? $[$ps:stx]* : $catStx) ← pure stx
|
||
| throwUnsupportedSyntax
|
||
let cat := catStx.getId.eraseMacroScopes
|
||
unless (Parser.isParserCategory (← getEnv) cat) do
|
||
throwErrorAt catStx "unknown category '{cat}'"
|
||
let syntaxParser := mkNullNode ps
|
||
-- If the user did not provide an explicit precedence, we assign `maxPrec` to atom-like syntax and `leadPrec` otherwise.
|
||
let precDefault := if isAtomLikeSyntax syntaxParser then Parser.maxPrec else Parser.leadPrec
|
||
let prec ← match prec? with
|
||
| some prec => liftMacroM <| evalPrec prec
|
||
| none => pure precDefault
|
||
let name ← match name? with
|
||
| some name => pure name.getId
|
||
| none => liftMacroM <| mkNameFromParserSyntax cat syntaxParser
|
||
let prio ← liftMacroM <| evalOptPrio prio?
|
||
let stxNodeKind := (← getCurrNamespace) ++ name
|
||
let catParserId := mkIdentFrom stx (cat.appendAfter "Parser")
|
||
let (val, lhsPrec?) ← runTermElabM none fun _ => Term.toParserDescr syntaxParser cat
|
||
let declName := mkIdentFrom stx name
|
||
let attrInstance ← `(attrInstance| $attrKind:attrKind $catParserId:ident $(quote prio):num)
|
||
let attrInstances := attrInstances.getD { elemsAndSeps := #[] }
|
||
let attrInstances := attrInstances.push attrInstance
|
||
let d ← if let some lhsPrec := lhsPrec? then
|
||
`($[$doc?:docComment]? @[$attrInstances,*] def $declName:ident : Lean.TrailingParserDescr :=
|
||
ParserDescr.trailingNode $(quote stxNodeKind) $(quote prec) $(quote lhsPrec) $val)
|
||
else
|
||
`($[$doc?:docComment]? @[$attrInstances,*] def $declName:ident : Lean.ParserDescr :=
|
||
ParserDescr.node $(quote stxNodeKind) $(quote prec) $val)
|
||
trace `Elab fun _ => d
|
||
withMacroExpansion stx d <| elabCommand d
|
||
|
||
@[builtinCommandElab «syntaxAbbrev»] def elabSyntaxAbbrev : CommandElab := fun stx => do
|
||
let `($[$doc?:docComment]? syntax $declName:ident := $[$ps:stx]*) ← pure stx | throwUnsupportedSyntax
|
||
-- TODO: nonatomic names
|
||
let (val, _) ← runTermElabM none fun _ => Term.toParserDescr (mkNullNode ps) Name.anonymous
|
||
let stxNodeKind := (← getCurrNamespace) ++ declName.getId
|
||
let stx' ← `($[$doc?:docComment]? def $declName:ident : Lean.ParserDescr := ParserDescr.nodeWithAntiquot $(quote (toString declName.getId)) $(quote stxNodeKind) $val)
|
||
withMacroExpansion stx stx' <| elabCommand stx'
|
||
|
||
def checkRuleKind (given expected : SyntaxNodeKind) : Bool :=
|
||
given == expected || given == expected ++ `antiquot
|
||
|
||
def inferMacroRulesAltKind : TSyntax ``matchAlt → CommandElabM SyntaxNodeKind
|
||
| `(matchAltExpr| | $pat:term => $_) => do
|
||
if !pat.raw.isQuot then
|
||
throwUnsupportedSyntax
|
||
let quoted := getQuotContent pat
|
||
pure quoted.getKind
|
||
| _ => throwUnsupportedSyntax
|
||
|
||
/--
|
||
Infer syntax kind `k` from first pattern, put alternatives of same kind into new `macro/elab_rules (kind := k)` via `mkCmd (some k)`,
|
||
leave remaining alternatives (via `mkCmd none`) to be recursively expanded. -/
|
||
def expandNoKindMacroRulesAux (alts : Array (TSyntax ``matchAlt)) (cmdName : String) (mkCmd : Option Name → Array (TSyntax ``matchAlt) → CommandElabM Command) : CommandElabM Command := do
|
||
let mut k ← inferMacroRulesAltKind alts[0]!
|
||
if k.isStr && k.getString! == "antiquot" then
|
||
k := k.getPrefix
|
||
if k == choiceKind then
|
||
throwErrorAt alts[0]!
|
||
"invalid {cmdName} alternative, multiple interpretations for pattern (solution: specify node kind using `{cmdName} (kind := ...) ...`)"
|
||
else
|
||
let altsK ← alts.filterM fun alt => return checkRuleKind (← inferMacroRulesAltKind alt) k
|
||
let altsNotK ← alts.filterM fun alt => return !checkRuleKind (← inferMacroRulesAltKind alt) k
|
||
if altsNotK.isEmpty then
|
||
mkCmd k altsK
|
||
else
|
||
`($(← mkCmd k altsK):command $(← mkCmd none altsNotK))
|
||
|
||
def strLitToPattern (stx: Syntax) : MacroM Syntax :=
|
||
match stx.isStrLit? with
|
||
| some str => return mkAtomFrom stx str
|
||
| none => Macro.throwUnsupported
|
||
|
||
builtin_initialize
|
||
registerTraceClass `Elab.syntax
|
||
|
||
end Lean.Elab.Command
|