feat(library/init/lean/parser/command): add inductive, structure and class parsers

library/init/lean/parser/command.lean

@@ -29,11 +29,11 @@ def docComment       := parser! "/--" >> commentBody
 def attrArg : Parser := ident <|> strLit <|> numLit
 def attrInstance     := parser! ident >> many attrArg
 def attributes       := parser! "@[" >> sepBy1 attrInstance ", " >> "]"
-def «private»        := parser! "private"
-def «protected»      := parser! "protected"
+def «private»        := parser! "private "
+def «protected»      := parser! "protected "
 def visibility       := «private» <|> «protected»
-def «noncomputable»  := parser! "noncomputable"
-def «unsafe»         := parser! "unsafe"
+def «noncomputable»  := parser! " noncomputable "
+def «unsafe»         := parser! " unsafe "
 def declModifiers    := parser! optional docComment >> optional «attributes» >> optional visibility >> optional «noncomputable» >> optional «unsafe»
 def declId           := parser! ident >> optional (".{" >> sepBy1 ident ", " >> "}")
 def declSig          := parser! many Term.bracktedBinder >> Term.typeSpec
@@ -48,9 +48,23 @@ def «constant»       := parser! "constant " >> declId >> declSig >> optional d
 def «instance»       := parser! "instance " >> optional declId >> declSig >> declVal
 def «axiom»          := parser! "axiom " >> declId >> declSig
 def «example»        := parser! "example " >> declSig >> declVal
+def relaxedInferMod  := parser! "{" >> "}"
+def strictInferMod   := parser! "(" >> ")"
+def inferMod         := relaxedInferMod <|> strictInferMod
+def introRule        := parser! " | " >> ident >> optional inferMod >> optDeclSig
+def «inductive»      := parser! "inductive " >> declId >> optDeclSig >> many introRule
+def structExplicitBinder := parser! "(" >> many ident >> optional inferMod >> optDeclSig >> optional Term.binderDefault >> ")"
+def structImplicitBinder := parser! "{" >> many ident >> optional inferMod >> optDeclSig >> "}"
+def structInstBinder     := parser! "[" >> many ident >> optional inferMod >> optDeclSig >> "]"
+def structFields         := parser! many (structExplicitBinder <|> structImplicitBinder <|> structInstBinder)
+def structCtor           := parser! ident >> optional inferMod >> " :: "
+def structureTk          := parser! "structure "
+def classTk              := parser! "class "
+def «extends»            := parser! " extends " >> sepBy1 termParser ", "
+def «structure»          := parser! (structureTk <|> classTk) >> declId >> many Term.bracktedBinder >> optional «extends» >> Term.optType >> " := " >> optional structCtor >> structFields
 
-@[builtinCommandParser] def declaration :=
-declModifiers >> («abbrev» <|> «def» <|> «theorem» <|> «constant» <|> «instance» <|> «axiom» <|> «example»)
+@[builtinCommandParser] def declaration := parser!
+declModifiers >> («abbrev» <|> «def» <|> «theorem» <|> «constant» <|> «instance» <|> «axiom» <|> «example» <|> «inductive» <|> «structure»)
 
 end Command
 

tests/playground/cmdparsertest1.lean

@@ -22,5 +22,9 @@ test [
 "protected def length.{u} {α : Type u} : List α → Nat
   | [] := 0
   | (a::as) := 1 + length as",
-"/-- doc string test -/   private theorem bla (x : Nat) : x = x := Eq.refl x"
+"/-- doc string test -/   private theorem bla (x : Nat) : x = x := Eq.refl x",
+"class Alternative (f : Type u → Type v) extends Applicative f : Type (max (u+1) v) :=
+(failure : ∀ {α : Type u}, f α)
+(orelse  : ∀ {α : Type u}, f α → f α → f α)
+"
 ]