lean4-htt/library/init/lean/path.lean
2019-07-25 19:28:22 -07:00

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/-
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 init.system.io
import init.system.filepath
import init.data.array
namespace Lean
open System.FilePath (pathSeparator searchPathSeparator)
private def pathSep : String := toString pathSeparator
private def searchPathSep : String := toString searchPathSeparator
def mkSearchPathRef : IO (IO.Ref (Array String)) :=
do curr ← IO.realPath ".";
IO.mkRef (Array.singleton curr)
@[init mkSearchPathRef]
constant searchPathRef : IO.Ref (Array String) := default _
def setSearchPath (s : String) : IO Unit :=
searchPathRef.set (s.split searchPathSep).toArray
def getBuiltinSearchPath : IO String :=
do appDir ← IO.appDir;
let libDir := appDir ++ pathSep ++ ".." ++ pathSep ++ "library";
IO.println libDir;
libDirExists ← IO.isDir libDir;
if libDirExists then
IO.realPath libDir
else do
let installedLibDir := appDir ++ pathSep ++ ".." ++ pathSep ++ "lib" ++ pathSep ++ "lean" ++ pathSep ++ "library";
installedLibDirExists ← IO.isDir installedLibDir;
IO.println installedLibDir;
if installedLibDirExists then do
IO.realPath installedLibDir
else
throw (IO.userError "failed to locate builtin search path, please set LEAN_PATH")
def getSearchPathFromEnv : IO (Option (List String)) :=
do val ← IO.getEnv "LEAN_PATH";
match val with
| none => pure none
| some val =>
pure $ val.split searchPathSep
def initSearchPath (path : Option String := "") : IO Unit :=
match path with
| some path => setSearchPath path
| none => do
path ← getSearchPathFromEnv;
match path with
| some path => searchPathRef.set path.toArray
| none => do
path ← getBuiltinSearchPath;
curr ← IO.realPath ".";
searchPathRef.set [path, curr].toArray
def findFile (fname : String) : IO (Option String) :=
do paths ← searchPathRef.get;
paths.mfind $ fun path => do
let curr := path ++ pathSep ++ fname;
ex ← IO.fileExists curr;
if ex then pure (some curr) else pure none
end Lean