lean4-htt/src/Lean/Meta/Reduce.lean
Joachim Breitner 60096e7d15
refactor: more idiomatic syntax for if h: (#5567)
https://github.com/leanprover/lean4/pull/5552 introduced a fair number
of `if h:`, but the slightly preferred style is `if h :`, with a space,
so here goes a quick `sed`.
2024-10-01 15:23:54 +00:00

48 lines
1.7 KiB
Text

/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
prelude
import Lean.Meta.Basic
import Lean.Meta.FunInfo
import Lean.Util.MonadCache
namespace Lean.Meta
partial def reduce (e : Expr) (explicitOnly skipTypes skipProofs := true) : MetaM Expr :=
let rec visit (e : Expr) : MonadCacheT Expr Expr MetaM Expr :=
checkCache e fun _ => Core.withIncRecDepth do
if (← (pure skipTypes <&&> isType e)) then
return e
else if (← (pure skipProofs <&&> isProof e)) then
return e
else
let e ← whnf e
match e with
| Expr.app .. =>
let f ← visit e.getAppFn
let nargs := e.getAppNumArgs
let finfo ← getFunInfoNArgs f nargs
let mut args := e.getAppArgs
for i in [:args.size] do
if h : i < finfo.paramInfo.size then
let info := finfo.paramInfo[i]
if !explicitOnly || info.isExplicit then
args ← args.modifyM i visit
else
args ← args.modifyM i visit
if f.isConstOf ``Nat.succ && args.size == 1 && args[0]!.isRawNatLit then
return mkRawNatLit (args[0]!.rawNatLit?.get! + 1)
else
return mkAppN f args
| Expr.lam .. => lambdaTelescope e fun xs b => do mkLambdaFVars xs (← visit b)
| Expr.forallE .. => forallTelescope e fun xs b => do mkForallFVars xs (← visit b)
| Expr.proj n i s .. => return mkProj n i (← visit s)
| _ => return e
visit e |>.run
def reduceAll (e : Expr) : MetaM Expr :=
reduce e false false false
end Lean.Meta