lean4-htt/library/init/lean/parser/reader/module.lean

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/-
Copyright (c) 2018 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Sebastian Ullrich
Module-level readers and macros
-/
prelude
import init.lean.parser.reader.token init.lean.parser.reader.term init.data.list.instances
namespace lean.parser
namespace reader
open combinators monad_parsec
def symbol_coe : has_coe string reader := ⟨symbol⟩
def seq_coe : has_coe_t (list reader) reader := ⟨seq⟩
local attribute [instance] symbol_coe seq_coe
-- coerce all list literals to `list reader`
local notation `[` l:(foldr `, ` (h t, @list.cons reader h t) list.nil `]`) := l
local postfix `?`:10000 := optional
local postfix *:10000 := many
local postfix +:10000 := many1
def «prelude» := {macro . name := `prelude}
def prelude.reader : reader :=
node «prelude» ["prelude"]
def import_path := {macro . name := `import_path}
def import_path.reader : reader :=
-- use `raw_symbol` to ignore registered tokens like ".."
node import_path [(raw_symbol ".")*, ident]
def «import» := {macro . name := `import}
def import.reader : reader :=
node «import» ["import", import_path.reader+]
section commands
def «open» := {macro . name := `open}
def open_export.reader : reader :=
[ident,
["as", ident]?,
[try ["(", ident], ident*, ")"]?,
[try ["(", "renaming"], [ident, "->", ident]+, ")"]?,
["(", "hiding", ident+, ")"]?
]+
def open.reader : reader :=
node «open» ["open", open_export.reader]
def «section» := {macro . name := `section}
def section.reader : reader :=
node «section» ["section", ident?, recurse*, "end", ident?]
def «notation» := {macro . name := `notation}
def prec : reader := [":", number]/-TODO <|> expr-/
def quoted_symbol : read_m syntax :=
do (s, info) ← with_source_info $ take_until (= '`'),
pure $ syntax.atom ⟨info, atomic_val.string s⟩
def notation_tk :=
any_of [
[raw_symbol "`", {read := quoted_symbol}, raw_symbol "`", prec?]
--TODO, {read := do tk ← token, /- check if reserved token-/}
]
def action : reader :=
[":", any_of [
number,
"max",
"prev",
"scoped"
/-TODO seq [
"(",
any_of ["foldl", "foldr"],
optional prec,
notation_tk,-/]]
def notation_reader : reader :=
any_of [
number,
[ident?,
[notation_tk,
(any_of [
["binder", prec?],
["binders", prec?],
[ident, action?]
])?
]*
]
]
def notation.reader : reader :=
node «notation» ["notation", notation_reader, ":=", term.reader]
def command.reader :=
with_recurse $ any_of [open.reader, section.reader, notation.reader] <?> "command"
/-- Read commands, recovering from errors inside commands (attach partial syntax tree)
as well as unknown commands (skip input). -/
private def commands_aux : bool → list syntax → nat → read_m syntax
| recovering cs 0 := error "unreachable"
-- on end of input, return list of parsed commands
| recovering cs (nat.succ n) := (eoi *> pure (syntax.node ⟨name.anonymous, cs.reverse⟩)) <|> do
(recovering, c) ← catch (do {
c ← command.reader.read,
pure (ff, some c)
} <|> do {
-- unknown command: try to skip token, or else single character
when (¬ recovering) $ do {
it ← left_over,
read_m.log_error $ to_string { parsec.message . expected := dlist.singleton "command", it := it, custom := () }
},
tk_start ← reader_state.token_start <$> get,
-- since the output of the following parser is never captured in a syntax tree...
try (token *> pure ()) <|> (any *> pure ()),
-- ...restore `token_start` after it
modify $ λ st, {st with token_start := tk_start},
pure (tt, none)
}) $ λ msg, do {
-- error inside command: advance input to error position, log error, return partial syntax tree
set_iterator msg.it,
modify $ λ st, {st with token_start := msg.it},
read_m.log_error (to_string msg),
pure (tt, some msg.custom)
},
commands_aux recovering (c.to_monad++cs) n
def commands.reader : reader :=
{ read := do { rem ← remaining, commands_aux ff [] rem.succ },
tokens := command.reader.tokens }
end commands
def module := {macro . name := `module}
def module.reader : reader :=
node module [prelude.reader?, import.reader*, commands.reader]
end reader
end lean.parser