# check_index.ludic — L4: the checker's name index. The emitter finds a declaration by scanning
# every one (find_fn, find_global, find_comp); a pass that asks about every call and every name
# builds a hash of them once instead. One table per kind of declaration.
const CK_SLOTS: int = 65536
var ck_fn_k: []pointer = new []pointer
var ck_fn_v: []Node = new []Node
var ck_gl_k: []pointer = new []pointer
var ck_gl_v: []Node = new []Node
var ck_rec_k: []pointer = new []pointer
var ck_rec_v: []Node = new []Node
var ck_en_k: []pointer = new []pointer
var ck_en_v: []Node = new []Node
var ck_ex_k: []pointer = new []pointer
var ck_ex_v: []Node = new []Node

function ck_hash(s: pointer) -> int {
  var h = 5381
  var i = 0
  let n = len(s)
  while i < n {
    h = (h * 33 + s[i]) % 1000003
    i += 1
  }
  return h % CK_SLOTS
}
function ck_tab_init(k: []pointer, v: []Node) -> void {
  var i = 0
  while i < CK_SLOTS {
    push(k, null)
    push(v, null)
    i += 1
  }
}
# the first declaration of a name wins, as it does in the emitter
function ck_tab_put(k: []pointer, v: []Node, name: pointer, d: Node) -> void {
  var h = ck_hash(name)
  while k[h] != null {
    if k[h] == name { return }
    h = (h + 1) % CK_SLOTS
  }
  k[h] = name
  v[h] = d
}
function ck_tab_get(k: []pointer, v: []Node, name: pointer) -> Node {
  if name == null { return null }
  var h = ck_hash(name)
  while k[h] != null {
    if k[h] == name { return v[h] }
    h = (h + 1) % CK_SLOTS
  }
  return null
}
function ck_index() -> void {
  ck_tab_init(ck_fn_k, ck_fn_v)
  ck_tab_init(ck_gl_k, ck_gl_v)
  ck_tab_init(ck_rec_k, ck_rec_v)
  ck_tab_init(ck_en_k, ck_en_v)
  ck_tab_init(ck_ex_k, ck_ex_v)
  var i = 0
  while i < len(prog) {
    let d = prog[i]
    if d.kind == N_FN { ck_tab_put(ck_fn_k, ck_fn_v, d.s, d) }
    if d.kind == N_VAR or d.kind == N_CONST { ck_tab_put(ck_gl_k, ck_gl_v, d.s, d) }
    if d.kind == N_COMP { ck_tab_put(ck_rec_k, ck_rec_v, d.s, d) }
    if d.kind == N_ENUM { ck_tab_put(ck_en_k, ck_en_v, d.s, d) }
    if d.kind == N_EXTERN { ck_tab_put(ck_ex_k, ck_ex_v, d.s, d) }
    i += 1
  }
}
function ck_fn(name: pointer) -> Node { return ck_tab_get(ck_fn_k, ck_fn_v, name) }
function ck_global(name: pointer) -> Node { return ck_tab_get(ck_gl_k, ck_gl_v, name) }
function ck_record(name: pointer) -> Node {
  let r = ck_tab_get(ck_rec_k, ck_rec_v, name)
  if r != null { return r }
  return gen_record(name)
}
function ck_enum(name: pointer) -> Node { return ck_tab_get(ck_en_k, ck_en_v, name) }
function ck_extern(name: pointer) -> Node { return ck_tab_get(ck_ex_k, ck_ex_v, name) }