structure Lean.Meta.ElimAltInfo : Type

• name : Lean.Name
• declName? : Option Lean.Name

  A declaration corresponding to the inductive constructor. (For custom recursors, the alternatives correspond to parameter names in the recursor, so we may not have a declaration to point to.) This is used for go-to-definition on the alternative name.

• numFields : Nat
• provesMotive : Bool

  If provesMotive := true, then this alternative has motive as its conclusion. Only for those alternatives the induction tactic should introduce reverted hypotheses.

instance Lean.Meta.instReprElimAltInfo : Repr Lean.Meta.ElimAltInfo

instance Lean.Meta.instInhabitedElimAltInfo : Inhabited Lean.Meta.ElimAltInfo

Equations

• Lean.Meta.instInhabitedElimAltInfo = { default := { name := default, declName? := default, numFields := default, provesMotive := default } }

structure Lean.Meta.ElimInfo : Type

Information about an eliminator as used by induction or cases.

Created from an expression by getElimInfo. This typically contains level metavariables that are instantiated as we go (e.g. in addImplicitTargets), so this is single use.

• elimExpr : Lean.Expr
• elimType : Lean.Expr
• motivePos : Nat
• targetsPos : Array Nat
• altsInfo : Array Lean.Meta.ElimAltInfo

instance Lean.Meta.instReprElimInfo : Repr Lean.Meta.ElimInfo

Equations

• Lean.Meta.instReprElimInfo = { reprPrec := Lean.Meta.reprElimInfo✝ }

instance Lean.Meta.instInhabitedElimInfo : Inhabited Lean.Meta.ElimInfo

def Lean.Meta.altArity (motive : Lean.Expr) (n : Nat) : Lean.Expr → Nat × Bool

Given the type t of an alternative, determines the number of parameters (.forall and .let)-bound, and whether the conclusion is a motive-application.

Equations

• Lean.Meta.altArity motive n (Lean.Expr.forallE binderName binderType b binderInfo) = Lean.Meta.altArity motive (n + 1) b
• Lean.Meta.altArity motive n (Lean.Expr.letE declName type value b nonDep) = Lean.Meta.altArity motive (n + 1) b
• Lean.Meta.altArity motive n x = (n, x.getAppFn == motive)

def Lean.Meta.getElimExprInfo (elimExpr : Lean.Expr) (baseDeclName? : Option Lean.Name := none) : Lean.MetaM Lean.Meta.ElimInfo

def Lean.Meta.getElimInfo (elimName : Lean.Name) (baseDeclName? : Option Lean.Name := none) : Lean.MetaM Lean.Meta.ElimInfo

Equations

• Lean.Meta.getElimInfo elimName baseDeclName? = do let __do_lift ← Lean.Meta.mkConstWithFreshMVarLevels elimName Lean.Meta.getElimExprInfo __do_lift baseDeclName?

def Lean.Meta.addImplicitTargets (elimInfo : Lean.Meta.ElimInfo) (targets : Array Lean.Expr) : Lean.MetaM (Array Lean.Expr)

Eliminators/recursors may have implicit targets. For builtin recursors, all indices are implicit targets. Given an eliminator and the sequence of explicit targets, this methods returns a new sequence containing implicit and explicit targets.

partial def Lean.Meta.addImplicitTargets.collect (elimInfo : Lean.Meta.ElimInfo) (targets : Array Lean.Expr) (type : Lean.Expr) (argIdx targetIdx : Nat) (implicits : Array Lean.MVarId) (targets' : Array Lean.Expr) : Lean.MetaM (Array Lean.MVarId × Array Lean.Expr)

structure Lean.Meta.CustomEliminator : Type

• induction : Bool
• typeNames : Array Lean.Name
• elimName : Lean.Name

instance Lean.Meta.instInhabitedCustomEliminator : Inhabited Lean.Meta.CustomEliminator

instance Lean.Meta.instReprCustomEliminator : Repr Lean.Meta.CustomEliminator

Equations

• Lean.Meta.instReprCustomEliminator = { reprPrec := Lean.Meta.reprCustomEliminator✝ }

structure Lean.Meta.CustomEliminators : Type

• map : Lean.SMap (Bool × Array Lean.Name) Lean.Name

instance Lean.Meta.instInhabitedCustomEliminators : Inhabited Lean.Meta.CustomEliminators

instance Lean.Meta.instReprCustomEliminators : Repr Lean.Meta.CustomEliminators

Equations

• Lean.Meta.instReprCustomEliminators = { reprPrec := Lean.Meta.reprCustomEliminators✝ }

def Lean.Meta.addCustomEliminatorEntry (es : Lean.Meta.CustomEliminators) (e : Lean.Meta.CustomEliminator) : Lean.Meta.CustomEliminators

opaque Lean.Meta.customEliminatorExt : Lean.SimpleScopedEnvExtension Lean.Meta.CustomEliminator Lean.Meta.CustomEliminators

def Lean.Meta.mkCustomEliminator (elimName : Lean.Name) (induction : Bool) : Lean.MetaM Lean.Meta.CustomEliminator

def Lean.Meta.addCustomEliminator (declName : Lean.Name) (attrKind : Lean.AttributeKind) (induction : Bool) : Lean.MetaM Unit

Equations

• Lean.Meta.addCustomEliminator declName attrKind induction = do let e ← Lean.Meta.mkCustomEliminator declName induction Lean.ScopedEnvExtension.add Lean.Meta.customEliminatorExt e attrKind

def Lean.Meta.getCustomEliminators : Lean.CoreM Lean.Meta.CustomEliminators

Gets all the eliminators defined using the @[induction_eliminator] and @[cases_eliminator] attributes.

def Lean.Meta.getCustomEliminator? (targets : Array Lean.Expr) (induction : Bool) : Lean.MetaM (Option Lean.Name)

Gets an eliminator appropriate for the provided array of targets. If induction is true then returns a matching eliminator defined using the @[induction_eliminator] attribute and otherwise returns one defined using the @[cases_eliminator] attribute.

The @[induction_eliminator] attribute is for the induction tactic and the @[cases_eliminator] attribute is for the cases tactic.