be06fc096a
better path going forward to handling upgrades. Old syntax files will stick around for compatibility purposes. Old syntax can be parsed into valid syntax trees via the old syntax (.peg) files, and then old syntax trees should be valid and can be upgraded via the normal code path. This change has lots of improvements to Nomsu codegen too.
127 lines
5.2 KiB
Plaintext
127 lines
5.2 KiB
Plaintext
-- This file contains the parser, which converts Nomsu text into abstract syntax trees
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lpeg = require 'lpeg'
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re = require 're'
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lpeg.setmaxstack 10000
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{:P,:R,:S,:C,:Cmt,:Carg} = lpeg
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{:match, :sub} = string
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{:insert, :remove} = table
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files = require 'files'
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{:NomsuCode, :LuaCode, :Source} = require "code_obj"
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AST = require "nomsu_tree"
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NOMSU_DEFS = with {}
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-- Newline supports either windows-style CR+LF or unix-style LF
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.nl = P("\r")^-1 * P("\n")
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.ws = S(" \t")
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.tonumber = tonumber
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.table = -> {}
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.unpack = unpack or table.unpack
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string_escapes = n:"\n", t:"\t", b:"\b", a:"\a", v:"\v", f:"\f", r:"\r"
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digit, hex = R('09'), R('09','af','AF')
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.escaped_char = (P("\\")*S("xX")*C(hex*hex)) / => string.char(tonumber(@, 16))
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.escaped_char += (P("\\")*C(digit*(digit^-2))) / => string.char(tonumber @)
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.escaped_char += (P("\\")*C(S("ntbavfr"))) / string_escapes
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.operator_char = S("'`~!@$^&*-+=|<>?/")
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.utf8_char = (
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R("\194\223")*R("\128\191") +
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R("\224\239")*R("\128\191")*R("\128\191") +
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R("\240\244")*R("\128\191")*R("\128\191")*R("\128\191"))
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.ident_char = R("az","AZ","09") + P("_") + .utf8_char
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.userdata = Carg(1)
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.add_comment = (src,end_pos,start_pos,comment,userdata)->
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userdata.comments[start_pos] = comment
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return true
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.error = (src,end_pos,start_pos,err_msg,userdata)->
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seen_errors = userdata.errors
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if seen_errors[start_pos]
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return true
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num_errors = 0
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for _ in pairs(seen_errors) do num_errors += 1
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if num_errors >= 10
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seen_errors[start_pos+1] = colored.bright colored.yellow colored.onred "Too many errors, canceling parsing..."
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return #src+1
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err_pos = start_pos
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line_no = files.get_line_number(src, err_pos)
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--src = files.read(userdata.source.filename)
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prev_line = line_no == 1 and "" or files.get_line(src, line_no-1)
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err_line = files.get_line(src, line_no)
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next_line = files.get_line(src, line_no+1)
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i = err_pos-files.get_line_starts(src)[line_no]
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pointer = ("-")\rep(i) .. "^"
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err_msg = colored.bright colored.yellow colored.onred (err_msg or "Parse error").." at #{userdata.source.filename}:#{line_no}:"
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if #prev_line > 0 then err_msg ..= "\n"..colored.dim(prev_line)
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err_line = colored.white(err_line\sub(1, i))..colored.bright(colored.red(err_line\sub(i+1,i+1)))..colored.dim(err_line\sub(i+2,-1))
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err_msg ..= "\n#{err_line}\n#{colored.red pointer}"
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if #next_line > 0 then err_msg ..= "\n"..colored.dim(next_line)
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seen_errors[start_pos] = err_msg
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return true
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setmetatable(NOMSU_DEFS, {__index:(key)=>
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make_node = (start, value, stop, userdata)->
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if userdata.source
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with userdata.source
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value.source = Source(.filename, .start + start-1, .start + stop-1)
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setmetatable(value, AST[key])
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value.comments = userdata.comments
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if value.__init then value\__init!
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return value
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self[key] = make_node
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return make_node
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})
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Parser = {version:2, patterns:{}}
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do
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-- Just for cleanliness, I put the language spec in its own file using a slightly modified
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-- version of the lpeg.re syntax.
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peg_tidier = re.compile [[
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file <- %nl* {~ (def/comment) (%nl+ (def/comment))* %nl* ~}
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def <- anon_def / captured_def
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anon_def <- ({ident} (" "*) ":"
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{~ ((%nl " "+ def_line?)+) / def_line ~}) -> "%1 <- %2"
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captured_def <- ({ident} (" "*) "(" {ident} ")" (" "*) ":"
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{~ ((%nl " "+ def_line?)+) / def_line ~}) -> "%1 <- (({} {| %3 |} {} %%userdata) -> %2)"
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def_line <- (err / [^%nl])+
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err <- ("(!!" { (!("!!)") .)* } "!!)") -> "(({} (%1) %%userdata) => error)"
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ident <- [a-zA-Z_][a-zA-Z0-9_]*
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comment <- "--" [^%nl]*
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]]
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for version=1,Parser.version
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peg_file = io.open("nomsu.#{version}.peg")
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if not peg_file and package.nomsupath
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for path in package.nomsupath\gmatch("[^;]+")
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peg_file = io.open(path.."/nomsu.#{version}.peg")
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break if peg_file
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assert(peg_file, "could not find nomsu .peg file")
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nomsu_peg = peg_tidier\match(peg_file\read('*a'))
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peg_file\close!
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Parser.patterns[version] = re.compile(nomsu_peg, NOMSU_DEFS)
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Parser.parse = (nomsu_code, source=nil, version=nil)->
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source or= nomsu_code.source
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nomsu_code = tostring(nomsu_code)
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version or= nomsu_code\match("^#![^\n]*nomsu[ ]+-V[ ]*([0-9.]+)")
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version = (version and tonumber(version)) or Parser.version
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userdata = {
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errors: {}, :source, comments: {}
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}
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tree = Parser.patterns[version]\match(nomsu_code, nil, userdata)
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unless tree
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error "In file #{colored.blue tostring(source or "<unknown>")} failed to parse:\n#{colored.onyellow colored.black nomsu_code}"
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if type(tree) == 'number'
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return nil
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if next(userdata.errors)
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keys = [k for k,v in pairs(userdata.errors)]
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table.sort(keys)
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errors = [userdata.errors[k] for k in *keys]
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error("Errors occurred while parsing (v#{version}):\n\n"..table.concat(errors, "\n\n"), 0)
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tree.version = userdata.version
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return tree
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return Parser
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