hex.input_dec_uint

dst[:n] = the unsigned decimal number read from input (mod 16^n).
Reads ASCII ‘0’..’9’ until a ‘\n’ or ‘\0’ (EOF) terminator;
jumps to error on any other byte. Inverse of hex.print_dec_uint.

Signature

def input_dec_uint n, dst, error @ loop, valid_hi, terminator, digit_char, add_digit, digit, byte, end { ... }

Defined in hex/input.fj — lines 102–124 (view on GitHub).

Complexity

• Time: ~ d(n(10@+39)) + (d+1)(7@+11)    (d = number of input digits; estimate)

• Space: ~ n(9@+132) + 8@+100             (estimate)

See the complexity glossary for what @, w, dw, dbit, n mean.

Requires init

The following must be initialised before this macro is invoked:

• hex.init

Source

Click to view the macro body

def input_dec_uint n, dst, error @ loop, valid_hi, terminator, digit_char, add_digit, digit, byte, end {
    .zero n, dst
    .zero n, digit
  loop:
    .input byte                                       // byte = [low nibble, high nibble]
    .if_flags byte+dw, (1<<0)|(1<<3), error, valid_hi // high nibble must be 0 (terminator) or 3 (digit)
  valid_hi:
    .if_flags byte+dw, 1<<3, terminator, digit_char
  terminator:
    .if_flags byte, (1<<0x0)|(1<<0xA), error, end     // '\0' (0x00) or '\n' (0x0A)
  digit_char:
    .if_flags byte, (1<<10)-1, error, add_digit       // low nibble must be 0..9
  add_digit:
    .mul10 n, dst
    .zero digit
    .xor digit, byte
    .add n, dst, digit
    ;loop

  digit: hex.vec n
  byte:  hex.vec 2
  end:
}

Depends on

• hex.add/3

• hex.if_flags

• hex.input/1

• hex.mul10

• hex.xor/2

• hex.zero/1

• hex.zero/2

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