str = string

dexprlist = sequence[dexpr]
dexpr = oneof[
	      acons: acs,
	      apply: op,
	      assign: assn,
	      const: con,
	      field: fspec,
	      idn: ident,
	      instance: instance,
	      none: null,
	      object: odesc,
	      scons: scs,
	      sel: sel,
	      tgen: tgen,
	      vcons: vcs
	      ]

odesc = record[value: _obj, 
	       ops: anop
	       ]

tgen = record[name: string,
		parms: list]

sel = record[name: string,
		parms: list]

instance = record[ops: anop]

acs = record[typ: string,
	     parm: list,
	     start: _obj,
	     vals: list
	     ]

scs = record[typ: string,
	     parms: list,
	     vals: list
	     ]

vcs = record[typ: string,
	     parms: list,
	     val: _obj,
	     tg: int
	     ]

fspec = record[name: string, typ: _obj]
fspeclist = sequence[fspec]

dvardesc = oneof[const: con, object: ops]


rinfo = record[signal_name: string, 
	       routine_name: string]

list = sequence[_obj]
ident = string
con = oneof[int_: int,
	    bool_: bool,
	    null_: null,
	    char_: char,
	    real_: real,
	    str: string
	    ]

assn = record[left: list,
	      right: list
	      ]

op = record[op: string,
	    tparms: list,
	    oparms: list,
	    args: list
	    ]
l2d = _cvt[list, dexprlist]
l2f = _cvt[list, fspeclist]
d2l = _cvt[dexprlist, list]
d2o = _cvt[dexpr, _obj]
o2d = _cvt[_obj, dexpr]
anop = _vec[_obj]
ops = sequence[anop]

rtn_info = record[a_nm: string,
		  b_fname: string,
		  c_is_iter: bool,
		  d_is_parmd: bool,
		  e_addr: int,
		  f_nargs: int,
		  g_vals: ops,
		  h_sigds: sigdesclist,
		  i_locals: ops,
		  j_owns: ops,
		  k_ptowns: ops,
		  l_popowns: ops,
		  m_type_formals: ss,
		  n_op_formals: ss
		  ]

sigdesclist = sequence[sigdesc]

sigdesc = record[a_nm: string,
		 b_vals: ops]

ss = sequence[string]

ss2l = _cvt[ss, list]