336 lines
13 KiB
Text
336 lines
13 KiB
Text
/-
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Copyright (c) 2019 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Sebastian Ullrich, Leonardo de Moura
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-/
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prelude
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import init.lean.name init.lean.format init.data.array
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namespace Lean
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/-- A hygiene marker introduced by a macro expansion. -/
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def MacroScope := Nat
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namespace MacroScope
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instance : DecidableEq MacroScope := inferInstanceAs (DecidableEq Nat)
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instance : HasFormat MacroScope := inferInstanceAs (HasFormat Nat)
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end MacroScope
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abbrev MacroScopes := List MacroScope
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structure SourceInfo :=
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/- Will be inferred after parsing by `Syntax.updateLeading`. During parsing,
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it is not at all clear what the preceding token was, especially with backtracking. -/
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(leading : Substring)
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(pos : String.Pos)
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(trailing : Substring)
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def SourceInfo.updateTrailing : SourceInfo → Substring → SourceInfo
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| ⟨leading, pos, _⟩ trailing := ⟨leading, pos, trailing⟩
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/- Node kind generation -/
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abbrev SyntaxNodeKind := Name
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@[matchPattern] def choiceKind : SyntaxNodeKind := `choice
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@[matchPattern] def nullKind : SyntaxNodeKind := `null
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def strLitKind : SyntaxNodeKind := `strLit
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def numLitKind : SyntaxNodeKind := `numLit
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/- Syntax AST -/
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inductive Syntax
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| missing
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| node (kind : SyntaxNodeKind) (args : Array Syntax) (scopes : MacroScopes)
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| atom (info : Option SourceInfo) (val : String)
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| ident (info : Option SourceInfo) (rawVal : Substring) (val : Name) (preresolved : List Name) (scopes : MacroScopes)
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instance stxInh : Inhabited Syntax :=
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⟨Syntax.missing⟩
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def Syntax.isMissing : Syntax → Bool
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| Syntax.missing := true
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| _ := false
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inductive IsNode : Syntax → Prop
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| mk (kind : SyntaxNodeKind) (args : Array Syntax) (scopes : MacroScopes) : IsNode (Syntax.node kind args scopes)
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def SyntaxNode : Type := {s : Syntax // IsNode s }
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def notIsNodeMissing (h : IsNode Syntax.missing) : False := match h with end
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def notIsNodeAtom {info val} (h : IsNode (Syntax.atom info val)) : False := match h with end
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def notIsNodeIdent {info rawVal val preresolved scopes} (h : IsNode (Syntax.ident info rawVal val preresolved scopes)) : False := match h with end
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def unreachIsNodeMissing {α : Type} (h : IsNode Syntax.missing) : α := False.elim (notIsNodeMissing h)
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def unreachIsNodeAtom {α : Type} {info val} (h : IsNode (Syntax.atom info val)) : α := False.elim (notIsNodeAtom h)
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def unreachIsNodeIdent {α : Type} {info rawVal val preresolved scopes} (h : IsNode (Syntax.ident info rawVal val preresolved scopes)) : α :=
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False.elim (match h with end)
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@[inline] def withArgs {α : Type} (n : SyntaxNode) (fn : Array Syntax → α) : α :=
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match n with
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| ⟨Syntax.node _ args _, _⟩ := fn args
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| ⟨Syntax.missing, h⟩ := unreachIsNodeMissing h
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| ⟨Syntax.atom _ _, h⟩ := unreachIsNodeAtom h
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| ⟨Syntax.ident _ _ _ _ _, h⟩ := unreachIsNodeIdent h
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@[inline] def updateArgs (n : SyntaxNode) (fn : Array Syntax → Array Syntax) : Syntax :=
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match n with
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| ⟨Syntax.node kind args scopes, _⟩ := Syntax.node kind (fn args) scopes
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| ⟨Syntax.missing, h⟩ := unreachIsNodeMissing h
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| ⟨Syntax.atom _ _, h⟩ := unreachIsNodeAtom h
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| ⟨Syntax.ident _ _ _ _ _, h⟩ := unreachIsNodeIdent h
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-- TODO(Sebastian): exhaustively argue why (if?) this is correct
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-- The basic idea is List concatenation with elimination of adjacent identical scopes
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def MacroScopes.flip : MacroScopes → MacroScopes → MacroScopes
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| ys [] := ys
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| ys (x::xs) := match MacroScopes.flip ys xs with
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| y::ys := if x == y then ys else x::y::ys
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| [] := [x]
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namespace Syntax
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def isIdent : Syntax → Bool
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| (Syntax.ident _ _ _ _ _) := true
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| _ := false
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def isOfKind : Syntax → SyntaxNodeKind → Bool
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| (Syntax.node kind _ _) k := k == kind
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| other _ := false
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def flipScopes (scopes : MacroScopes) : Syntax → Syntax
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| (Syntax.ident info rawVal val pre scopes) := Syntax.ident info rawVal val pre (scopes.flip scopes)
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| (Syntax.node kind args scopes) := Syntax.node kind args (scopes.flip scopes)
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| other := other
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@[inline] def toSyntaxNode {α : Type} (s : Syntax) (base : α) (fn : SyntaxNode → α) : α :=
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match s with
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| Syntax.node kind args [] := fn ⟨Syntax.node kind args [], IsNode.mk _ _ _⟩
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| Syntax.node kind args scopes := fn ⟨Syntax.node kind (args.map (flipScopes scopes)) [], IsNode.mk _ _ _⟩
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| other := base
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@[specialize] partial def mreplace {m : Type → Type} [Monad m] (fn : Syntax → m (Option Syntax)) : Syntax → m Syntax
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| stx@(node kind args scopes) := do
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o ← fn stx;
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(match o with
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| some stx := pure stx
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| none := do args ← args.mmap mreplace; pure (node kind args scopes))
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| stx := do o ← fn stx; pure (o.getOrElse stx)
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@[inline] def replace {m : Type → Type} [Monad m] (fn : Syntax → m (Option Syntax)) := @mreplace Id _
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private def updateInfo : SourceInfo → String.Pos → SourceInfo
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| {leading := {str := s, startPos := _, stopPos := _}, pos := pos, trailing := trailing} last :=
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{leading := {str := s, startPos := last, stopPos := pos}, pos := pos, trailing := trailing}
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/- Remark: the State `String.Pos` is the `SourceInfo.trailing.endPos` of the previous token,
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or the beginning of the String. -/
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@[inline]
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private def updateLeadingAux : Syntax → State String.Pos (Option Syntax)
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| (atom (some info) val) := do
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last ← get;
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set info.trailing.stopPos;
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let newInfo := updateInfo info last;
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pure $ some (atom (some newInfo) val)
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| (ident (some info) rawVal val pre scopes) := do
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last ← get;
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set info.trailing.stopPos;
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let newInfo := updateInfo info last;
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pure $ some (ident (some newInfo) rawVal val pre scopes)
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| _ := pure none
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/-- Set `SourceInfo.leading` according to the trailing stop of the preceding token.
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The Result is a round-tripping Syntax tree IF, in the input Syntax tree,
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* all leading stops, atom contents, and trailing starts are correct
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* trailing stops are between the trailing start and the next leading stop.
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Remark: after parsing all `SourceInfo.leading` fields are Empty.
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The Syntax argument is the output produced by the Parser for `source`.
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This Function "fixes" the `source.leanding` field.
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Note that, the `SourceInfo.trailing` fields are correct.
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The implementation of this Function relies on this property. -/
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def updateLeading : Syntax → Syntax :=
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λ stx, Prod.fst <$> (mreplace updateLeadingAux stx).run 0
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partial def updateTrailing (trailing : Substring) : Syntax → Syntax
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| (Syntax.atom (some info) val) := Syntax.atom (some (info.updateTrailing trailing)) val
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| (Syntax.ident (some info) rawVal val pre scopes) := Syntax.ident (some (info.updateTrailing trailing)) rawVal val pre scopes
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| n@(Syntax.node k args scopes) :=
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if args.size == 0 then n
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else
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let i := args.size - 1;
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let last := updateTrailing (args.get i);
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let args := args.set i last;
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Syntax.node k args scopes
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| other := other
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/-- Retrieve the left-most leaf's info in the Syntax tree. -/
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partial def getHeadInfo : Syntax → Option SourceInfo
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| (atom info _) := info
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| (ident info _ _ _ _ ) := info
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| (node _ args _) := args.find getHeadInfo
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| _ := none
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def getPos (stx : Syntax) : Option String.Pos :=
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SourceInfo.pos <$> stx.getHeadInfo
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private def reprintLeaf : Option SourceInfo → String → String
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| none val := val
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| (some info) val := info.leading.toString ++ val ++ info.trailing.toString
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partial def reprint : Syntax → Option String
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| (atom info val) := reprintLeaf info val
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| (ident info rawVal _ _ _) := reprintLeaf info rawVal.toString
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| (node kind args _) :=
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if kind == choiceKind then
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if args.size == 0 then failure
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else do
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s ← reprint (args.get 0);
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args.mfoldlFrom (λ s stx, do s' ← reprint stx; guard (s == s'); pure s) s 1
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else args.mfoldl (λ r stx, do s ← reprint stx; pure $ r ++ s) ""
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| missing := ""
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open Lean.Format
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protected partial def formatStx : Syntax → Format
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| (atom info val) := format $ repr val
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| (ident _ _ val pre scopes) :=
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let scopes := pre.map format ++ scopes.reverse.map format;
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let scopes := match scopes with [] := format "" | _ := bracket "{" (joinSep scopes ", ") "}";
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format "`" ++ format val ++ scopes
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| (node kind args scopes) :=
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let scopes := match scopes with [] := format "" | _ := bracket "{" (joinSep scopes.reverse ", ") "}";
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if kind = `Lean.Parser.noKind then
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sbracket $ scopes ++ joinSep (args.toList.map formatStx) line
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else
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let shorterName := kind.replacePrefix `Lean.Parser Name.anonymous;
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paren $ joinSep ((format shorterName ++ scopes) :: args.toList.map formatStx) line
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| missing := "<missing>"
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instance : HasFormat Syntax := ⟨Syntax.formatStx⟩
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instance : HasToString Syntax := ⟨toString ∘ format⟩
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end Syntax
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/- Helper functions for creating Syntax objects using C++ -/
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@[export lean.mk_syntax_atom_core]
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def mkSimpleAtom (val : String) : Syntax :=
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Syntax.atom none val
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@[export lean.mk_syntax_ident_core]
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def mkSimpleIdent (val : Name) : Syntax :=
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Syntax.ident none (toString val).toSubstring val [] []
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@[export lean.mk_syntax_list_core]
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def mkListNode (args : Array Syntax) : Syntax :=
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Syntax.node nullKind args []
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/- Helper functions for creating string and numeric literals -/
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def mkLit (kind : SyntaxNodeKind) (val : String) (info : Option SourceInfo := none) : Syntax :=
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let atom := Syntax.atom info val;
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Syntax.node kind (Array.singleton atom) []
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def mkStrLit (val : String) (info : Option SourceInfo := none) : Syntax :=
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mkLit strLitKind val info
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def mkNumLit (val : String) (info : Option SourceInfo := none) : Syntax :=
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mkLit numLitKind val info
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@[export lean.mk_syntax_str_lit_core]
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def mkStrLitAux (val : String) : Syntax :=
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mkStrLit val
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@[export lean.mk_syntax_num_lit_core]
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def mkNumLitAux (val : Nat) : Syntax :=
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mkNumLit (toString val)
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namespace Syntax
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def isStrLit : Syntax → Option String
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| (Syntax.node k args _) :=
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if k == strLitKind && args.size == 1 then
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match args.get 0 with
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| (Syntax.atom _ val) := some val
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| _ := none
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else
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none
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| _ := none
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/- Recall that we don't have special Syntax constructors for storing numeric atoms.
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The idea is to have an extensible approach where embedded DSLs may have new kind of atoms and/or
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different ways of representing them. So, our atoms contain just the parsed string.
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The main Lean parser uses the kind `numLitKind` for storing natural numbers that can be encoded
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in binary, octal, decimal and hexadecimal format. `isNatLit` implements a "decoder"
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for Syntax objects representing these numerals. -/
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private partial def decodeBinLitAux (s : String) : Nat → Nat → Option Nat
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| i val :=
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if s.atEnd i then some val
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else
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let c := s.get i;
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if c == '0' then decodeBinLitAux (s.next i) (2*val)
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else if c == '1' then decodeBinLitAux (s.next i) (2*val + 1)
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else none
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private partial def decodeOctalLitAux (s : String) : Nat → Nat → Option Nat
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| i val :=
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if s.atEnd i then some val
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else
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let c := s.get i;
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if '0' ≤ c && c ≤ '7' then decodeOctalLitAux (s.next i) (8*val + c.toNat - '0'.toNat)
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else none
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private partial def decodeHexLitAux (s : String) : Nat → Nat → Option Nat
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| i val :=
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if s.atEnd i then some val
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else
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let c := s.get i;
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if '0' ≤ c && c ≤ '9' then decodeHexLitAux (s.next i) (16*val + c.toNat - '0'.toNat)
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else if 'a' ≤ c && c ≤ 'f' then decodeHexLitAux (s.next i) (16*val + 10 + c.toNat - 'a'.toNat)
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else if 'A' ≤ c && c ≤ 'F' then decodeHexLitAux (s.next i) (16*val + 10 + c.toNat - 'A'.toNat)
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else none
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private partial def decodeDecimalLitAux (s : String) : Nat → Nat → Option Nat
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| i val :=
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if s.atEnd i then some val
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else
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let c := s.get i;
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if '0' ≤ c && c ≤ '9' then decodeDecimalLitAux (s.next i) (10*val + c.toNat - '0'.toNat)
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else none
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private def decodeNatLitVal (s : String) : Option Nat :=
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let len := s.length;
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if len == 0 then none
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else
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let c := s.get 0;
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if c == '0' then
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if len == 1 then some 0
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else
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let c := s.get 1;
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if c == 'x' || c == 'X' then decodeHexLitAux s 2 0
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else if c == 'b' || c == 'B' then decodeBinLitAux s 2 0
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else if c == 'o' || c == 'O' then decodeOctalLitAux s 2 0
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else if c.isDigit then decodeDecimalLitAux s 0 0
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else none
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else if c.isDigit then decodeDecimalLitAux s 0 0
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else none
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def isNatLit : Syntax → Option Nat
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| (Syntax.node k args _) :=
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if k == numLitKind && args.size == 1 then
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match args.get 0 with
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| (Syntax.atom _ val) := decodeNatLitVal val
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| _ := none
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else
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none
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| _ := none
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def isIdOrAtom : Syntax → Option String
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| (Syntax.atom _ val) := some val
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| (Syntax.ident _ rawVal _ _ _) := some rawVal.toString
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| _ := none
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end Syntax
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end Lean
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