Files
lean4/script/Modulize.lean
2026-01-21 20:25:13 +00:00

78 lines
3.0 KiB
Lean4

import Lake.CLI.Main
/-!
Usage: `lean --run script/Modulize.lean [--meta] file1.lean file2.lean ...`
A simple script that inserts `module` and `public section` into un-modulized files and
bumps their imports to `public`.
When `--meta` is passed, `public meta section` and `public meta import` is used instead.
-/
open Lean Parser.Module
def main (args : List String) : IO Unit := do
let mut args := args
let mut doMeta := false
while !args.isEmpty && args[0]!.startsWith "-" do
match args[0]! with
| "--meta" => doMeta := true
| arg => throw <| .userError s!"unknown flag '{arg}'"
args := args.tail
for path in args do
-- Parse the input file
let mut text IO.FS.readFile path
let inputCtx := Parser.mkInputContext text path
let (header, parserState, msgs) Parser.parseHeader inputCtx
if !msgs.toList.isEmpty then -- skip this file if there are parse errors
msgs.forM fun msg => msg.toString >>= IO.println
throw <| .userError "parse errors in file"
let `(header| $[module%$moduleTk?]? $[prelude%$preludeTk?]? $imps:import*) := header
| throw <| .userError s!"unexpected header syntax of {path}"
if moduleTk?.isSome then
continue
-- initial whitespace if empty header
let startPos := header.raw.getPos? |>.getD parserState.pos
let dummyEnv mkEmptyEnvironment
let (initCmd, parserState', msgs') :=
Parser.parseCommand inputCtx { env := dummyEnv, options := {} } parserState msgs
-- insert section if any trailing command (or error, which could be from an unknown command)
if !initCmd.isOfKind ``Parser.Command.eoi || msgs'.hasErrors then
let insertPos? :=
-- put below initial module docstring if any
guard (initCmd.isOfKind ``Parser.Command.moduleDoc) *> initCmd.getTailPos? <|>
-- else below header
header.raw.getTailPos?
let insertPos := insertPos?.getD startPos -- empty header
let mut sec := if doMeta then
"public meta section"
else
"@[expose] public section"
if !imps.isEmpty then
sec := "\n\n" ++ sec
if insertPos?.isNone then
sec := sec ++ "\n\n"
let insertPos := text.pos! insertPos
text := text.extract text.startPos insertPos ++ sec ++ text.extract insertPos text.endPos
-- prepend each import with `public `
for imp in imps.reverse do
let insertPos := imp.raw.getPos?.get!
let prfx := if doMeta then "public meta " else "public "
let insertPos := text.pos! insertPos
text := text.extract text.startPos insertPos ++ prfx ++ text.extract insertPos text.endPos
-- insert `module` header
let mut initText := text.extract text.startPos (text.pos! startPos)
if !initText.trimAscii.isEmpty then
-- If there is a header comment, preserve it and put `module` in the line after
initText := initText.trimAsciiEnd.toString ++ "\n"
text := initText ++ "module\n\n" ++ text.extract (text.pos! startPos) text.endPos
IO.FS.writeFile path text