Dawid Sobczak
e6b88d5a0f
The goal of stage 06 is to try parse zig synax in lua. I pulled in lpeglable 1.2.0 and parser-gen off github to get started. All of this needs to be cleaned up rather soon. Lua boostraps using tcc and musl from the previous stage. Since musl 0.6.0 doesn't support dynamic linking this build of lua doesn't support shared libraries. I couldn't easily patch musl with dlopen and friends so instead I link statically and call deps with c api.
55 lines
1.5 KiB
Lua
55 lines
1.5 KiB
Lua
package.path = package.path .. ";../?.lua"
|
|
local pg = require "parser-gen"
|
|
local peg = require "peg-parser"
|
|
local errs = {errMissingThen = "Missing Then"}
|
|
pg.setlabels(errs)
|
|
|
|
|
|
local grammar = pg.compile([[
|
|
|
|
program <- stmtsequence !.
|
|
stmtsequence <- statement (';' statement)*
|
|
statement <- ifstmt / repeatstmt / assignstmt / readstmt / writestmt
|
|
ifstmt <- 'if' exp 'then'^errMissingThen stmtsequence elsestmt? 'end'
|
|
elsestmt <- ('else' stmtsequence)
|
|
repeatstmt <- 'repeat' stmtsequence 'until' exp
|
|
assignstmt <- IDENTIFIER ':=' exp
|
|
readstmt <- 'read' IDENTIFIER
|
|
writestmt <- 'write' exp
|
|
exp <- simpleexp (COMPARISONOP simpleexp)*
|
|
COMPARISONOP <- '<' / '='
|
|
simpleexp <- term (ADDOP term)*
|
|
ADDOP <- [+-]
|
|
term <- factor (MULOP factor)*
|
|
MULOP <- [*/]
|
|
factor <- '(' exp ')' / NUMBER / IDENTIFIER
|
|
|
|
NUMBER <- '-'? [0-9]+
|
|
KEYWORDS <- 'if' / 'repeat' / 'read' / 'write' / 'then' / 'else' / 'end' / 'until'
|
|
RESERVED <- KEYWORDS ![a-zA-Z]
|
|
IDENTIFIER <- !RESERVED [a-zA-Z]+
|
|
HELPER <- ';' / %nl / %s / KEYWORDS / !.
|
|
SYNC <- (!HELPER .)*
|
|
|
|
]], _, true)
|
|
local errors = 0
|
|
local function printerror(desc,line,col,sfail,trec)
|
|
errors = errors+1
|
|
print("Error #"..errors..": "..desc.." on line "..line.."(col "..col..")")
|
|
end
|
|
|
|
|
|
local function parse(input)
|
|
errors = 0
|
|
result, errors = pg.parse(input,grammar,printerror)
|
|
return result, errors
|
|
end
|
|
|
|
if arg[1] then
|
|
-- argument must be in quotes if it contains spaces
|
|
res, errs = parse(arg[1])
|
|
peg.print_t(res)
|
|
peg.print_r(errs)
|
|
end
|
|
local ret = {parse=parse}
|
|
return ret
|