# buf.ludic — a growable byte buffer for building IR text. The emitter writes
# module-level material (types, globals, string constants) into one buffer and
# function bodies into another, then prints them in order.

struct Buf { data: ptr = ptr_null(), len: int = 0, cap: int = 0 }

fn buf_new() -> Buf {
  let b = new Buf
  b.cap = 256
  b.data = mem_alloc(b.cap)
  b.len = 0
  return b
}
fn buf_ensure(b: Buf, extra: int) -> void {
  if b.len + extra + 1 <= b.cap { return }
  while b.len + extra + 1 > b.cap { b.cap = b.cap * 2 }
  b.data = mem_realloc(b.data, b.cap)
}
fn buf_putc(b: Buf, c: int) -> void {
  buf_ensure(b, 1)
  poke8(b.data, b.len, c)
  b.len = b.len + 1
}
fn buf_puts(b: Buf, s: ptr) -> void {
  let i = 0
  while peek8(s, i) != 0 { buf_putc(b, peek8(s, i)); i = i + 1 }
}
fn buf_puti(b: Buf, n: int) -> void { buf_puts(b, itoa(n)) }
fn buf_str(b: Buf) -> ptr { poke8(b.data, b.len, 0); return b.data }