86a3219e7f
"package.nomsupath" to search for files in different locations, and prioritizing use of "luafilesystem" over system calls.
124 lines
5.4 KiB
Plaintext
124 lines
5.4 KiB
Plaintext
-- This file contains the parser, which converts Nomsu text into abstract syntax trees
|
|
lpeg = require 'lpeg'
|
|
re = require 're'
|
|
lpeg.setmaxstack 10000
|
|
{:P,:R,:V,:S,:Cg,:C,:Cp,:B,:Cmt,:Carg} = lpeg
|
|
utils = require 'utils'
|
|
{:match, :sub, :rep, :gsub, :format, :byte, :match, :find} = string
|
|
{:NomsuCode, :LuaCode, :Source} = require "code_obj"
|
|
AST = require "nomsu_tree"
|
|
|
|
NOMSU_DEFS = with {}
|
|
-- Newline supports either windows-style CR+LF or unix-style LF
|
|
.nl = P("\r")^-1 * P("\n")
|
|
.ws = S(" \t")
|
|
.tonumber = tonumber
|
|
string_escapes = n:"\n", t:"\t", b:"\b", a:"\a", v:"\v", f:"\f", r:"\r"
|
|
digit, hex = R('09'), R('09','af','AF')
|
|
.escaped_char = (P("\\")*S("xX")*C(hex*hex)) / => string.char(tonumber(@, 16))
|
|
.escaped_char += (P("\\")*C(digit*(digit^-2))) / => string.char(tonumber @)
|
|
.escaped_char += (P("\\")*C(S("ntbavfr"))) / string_escapes
|
|
.operator_char = S("'`~!@$^&*-+=|<>?/")
|
|
.utf8_char = (
|
|
R("\194\223")*R("\128\191") +
|
|
R("\224\239")*R("\128\191")*R("\128\191") +
|
|
R("\240\244")*R("\128\191")*R("\128\191")*R("\128\191"))
|
|
.ident_char = R("az","AZ","09") + P("_") + .utf8_char
|
|
|
|
-- If the line begins with #indent+4 spaces, the pattern matches *those* spaces
|
|
-- and adds them to the current indent (not any more).
|
|
.indent = Cmt Carg(1), (start, userdata)=>
|
|
indented = userdata.indent..' '
|
|
if sub(@, start, start+#indented-1) == indented
|
|
userdata.indent = indented
|
|
return start + #indented
|
|
-- If the number of leading space characters is <= the number of spaces in the current
|
|
-- indent minus 4, this pattern matches and decrements the current indent exactly once.
|
|
.dedent = Cmt Carg(1), (start, userdata)=>
|
|
dedented = sub(userdata.indent, 1, -5)
|
|
if #match(@, "^[ ]*", start) <= #dedented
|
|
userdata.indent = dedented
|
|
return start
|
|
-- If the number of leading space characters is >= the number of spaces in the current
|
|
-- indent, this pattern matches and does not modify the indent.
|
|
.nodent = Cmt Carg(1), (start, userdata)=>
|
|
if sub(@, start, start+#userdata.indent-1) == userdata.indent
|
|
return start + #userdata.indent
|
|
|
|
.userdata = Carg(1)
|
|
|
|
.error = (src,end_pos,start_pos,err_msg,userdata)->
|
|
seen_errors = userdata.errors
|
|
if seen_errors[start_pos]
|
|
return true
|
|
if utils.size(seen_errors) >= 10
|
|
seen_errors[start_pos+1] = colored.bright colored.yellow colored.onred "Too many errors, canceling parsing..."
|
|
return #src+1
|
|
err_pos = start_pos
|
|
line_no = pos_to_line(src, err_pos)
|
|
src = FILE_CACHE[userdata.source.filename]
|
|
line_starts = LINE_STARTS[src]
|
|
prev_line = line_no == 1 and "" or src\sub(line_starts[line_no-1] or 1, line_starts[line_no]-2)
|
|
err_line = src\sub(line_starts[line_no], (line_starts[line_no+1] or 0)-2)
|
|
next_line = src\sub(line_starts[line_no+1] or -1, (line_starts[line_no+2] or 0)-2)
|
|
i = err_pos-line_starts[line_no]
|
|
pointer = ("-")\rep(i) .. "^"
|
|
err_msg = colored.bright colored.yellow colored.onred (err_msg or "Parse error").." at #{userdata.source.filename}:#{line_no}:"
|
|
if #prev_line > 0 then err_msg ..= "\n"..colored.dim(prev_line)
|
|
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))
|
|
err_msg ..= "\n#{err_line}\n#{colored.red pointer}"
|
|
if #next_line > 0 then err_msg ..= "\n"..colored.dim(next_line)
|
|
seen_errors[start_pos] = err_msg
|
|
return true
|
|
|
|
setmetatable(NOMSU_DEFS, {__index:(key)=>
|
|
make_node = (start, value, stop, userdata)->
|
|
if userdata.source
|
|
with userdata.source
|
|
value.source = Source(.filename, .start + start-1, .start + stop-1)
|
|
setmetatable(value, AST[key])
|
|
if value.__init then value\__init!
|
|
for i=1,#value do assert(value[i])
|
|
return value
|
|
|
|
self[key] = make_node
|
|
return make_node
|
|
})
|
|
|
|
NOMSU_PATTERN = do
|
|
-- Just for cleanliness, I put the language spec in its own file using a slightly modified
|
|
-- version of the lpeg.re syntax.
|
|
peg_tidier = re.compile [[
|
|
file <- {~ %nl* (def/comment) (%nl+ (def/comment))* %nl* ~}
|
|
def <- anon_def / captured_def
|
|
anon_def <- ({ident} (" "*) ":"
|
|
{((%nl " "+ [^%nl]*)+) / ([^%nl]*)}) -> "%1 <- %2"
|
|
captured_def <- ({ident} (" "*) "(" {ident} ")" (" "*) ":"
|
|
{((%nl " "+ [^%nl]*)+) / ([^%nl]*)}) -> "%1 <- (({} %3 {} %%userdata) -> %2)"
|
|
ident <- [a-zA-Z_][a-zA-Z0-9_]*
|
|
comment <- "--" [^%nl]*
|
|
]]
|
|
nomsu_peg = peg_tidier\match(io.open((package.nomsupath or '.').."/nomsu.peg")\read('*a'))
|
|
re.compile(nomsu_peg, NOMSU_DEFS)
|
|
|
|
parse = (nomsu_code, source=nil)->
|
|
nomsu_code = tostring(nomsu_code)
|
|
userdata = {
|
|
indent: "", errors: {}, :source
|
|
}
|
|
tree = NOMSU_PATTERN\match(nomsu_code, nil, userdata)
|
|
unless tree
|
|
error "In file #{colored.blue tostring(source or "<unknown>")} failed to parse:\n#{colored.onyellow colored.black nomsu_code}"
|
|
if type(tree) == 'number'
|
|
tree = nil
|
|
|
|
if next(userdata.errors)
|
|
keys = utils.keys(userdata.errors)
|
|
table.sort(keys)
|
|
errors = [userdata.errors[k] for k in *keys]
|
|
error("Errors occurred while parsing:\n\n"..table.concat(errors, "\n\n"), 0)
|
|
|
|
return tree
|
|
|
|
return parse
|