Parsel

A parser combinator library for Lua

Usage

local p = require 'parsel'

local digitsParser = p.oneOrMore(p.digit())
local intParserToNumber = p.map(digitsParser, function(digits)
  return tonumber(table.concat(digits, ""))
end)
local parsed = p.parse("1234", intParserToNumber)
print(parsed.result)
-- 1234

Available Parsers

local Parsel = require 'parsel'
Parsel.literal (lit) -- Parse any string literal
Parsel.letter () -- Parse any alphabetic letter
Parsel.digit () -- Parse any digit
Parsel.char () -- Match any single character
Parsel.charExcept (char) -- Match anything but the specified literal single character
Parsel.newline () -- Match single newline char
Parsel.whitespace () -- Match whitespace Matches at least one tab, space, or newline and consumes it
Parsel.optionalWhitespace () -- Match optional whitespace Optionally matches and consumes spaces, tabs and newlines
Parsel.anyLiteral (...) -- Match any literal passed in, succeeds with the match
Parsel.untilLiteral (literal) -- Match the parsers string until the specified literal is found

Available combinators

local Parsel = require 'parsel'
Parsel.any (...) -- Parse any combinators specified in the list
Parsel.either (p1, p2) -- Try first parser, and if that fails, try the second parser
Parsel.oneOrMore (p) -- Parse a combinator at least one time and until the parse fails
Parsel.seq (...) -- Parse all combinators in sequence
Parsel.zeroOrMore (p) -- Parse zero or more instances of combinators
Parsel.optional (p) -- Optionally parse a combinator, return Parsel.nullResult if not matched
Parsel.lazy (f) -- Returns a parser that lazily evaluates a function
Parsel.sepBy (p, delim) -- Match parsers delimited by successful parse of delim
Parsel.sepByAllowTrailing (p, delim) -- Like sepBy, but allow one trailing delim
Parsel.exclude (p, exclusionFunc) -- Fails a parser if it matches condition set by exclusionFunc

Parsing Lua source code

Parsel also comes with a lua parser under the luast/ directory

local p = require 'lua_parser'
local tree, err = p.parse([[local foo = "bar"]])
if err then
  print(err)
end
p.print(tree)
--[[
{
 1: {
   "type": "assignment"
   "value": {
     "type": "string"
     "value": "bar"
   }
   "ident": {
     "type": "identifier"
     "value": "foo"
   }
   "scope": "LOCAL"
 }
}
]]