argparse

argparse is a feature-rich command line parser for Lua inspired by argparse for Python.

Not everything stated here is implemented.

Features:

• Declarative and usual interfaces.

  Declarative:

  parser:argument "input"
     :description "Path to input file. "
     :convert(io.open)
  parser:option "-v" "--verbose"
     :description "Sets logging level. "
     :count "*"
  

  Usual:

  parser:argument("input", {
     description = "Path to input file. ",
     convert = io.open
  })
  parser:option("-v", "--verbose", {
     description  = "Sets logging level. ",
     count = "*"
  })
  

• Parses:

  • Short options(e.g. -q);
  • Combined short options(e.g. -zx);
  • Short options combined with arguments(e.g. -I/usr/local/include);
  • Long options(e.g. --quiet);
  • Long options with arguments(e.g. --from there);
  • GNU-style long options with arguments(e.g. --from=there).

• Supports named arguments consuming several arguments.

• Supports options and flags which can be invoked several times, consuming several arguments.

  Example:

  parser:option "-p" "--pair"
     :count "*"
     :args(2)
  
  parser:flag "-v" "--verbose"
     :count "*"
  
  local args = parser:parse{"--pair", "Alice", "Bob", "-p", "Emma", "John", "-vvv"}
  -- args = {
  --    pair = {
  --       {"Alice", "Bob"},
  --       {"Emma", "John"}
  --    },
  --    verbose = 3
  -- }
  

• Supports default values and automatic conversions for arguments.

• Automatically generates error, usage and help(NYI) messages.

• Supports commands(e.g. in git CLI add, commit, push, etc. are commands). Each command has its own set of options and arguments.