Crystalの入力を爆速にする

執筆途中です

getchar_unlocked

hr.icon

↑これから若干修正しています（末尾に改行がない場合壊れた問題を修正）

moduleに変更

code: (cr)

module FastIn

extend self

lib LibC

fun getchar = getchar_unlocked : Char

end

module Scanner

extend self

{% for int_t in Int::Primitive.union_types %}

{% if Int::Signed.union_types.includes?(int_t) %}

{% else %}

{% end %}

c = next_char

res = {{ int_t }}.new(c.ord - '0'.ord)

sgn = 1

case c

when '-'

res = {{ int_t }}.new(LibC.getchar.ord - '0'.ord)

sgn = -1

when '+'

res = {{ int_t }}.new(LibC.getchar.ord - '0'.ord)

end

until ascii_voidchar?(c = LibC.getchar)

res = (res << 1) + (res << 3) + (c.ord ^ 48)

end

res * sgn + offset

end

{% end %}

def read_char : Char

next_char

end

def read_word : String

c = next_char

until ascii_voidchar?(c = LibC.getchar)

s << c

end

s.join

end

private def next_char : Char

c = '_'

while ascii_voidchar?(c = LibC.getchar)

end

c

end

private def ascii_voidchar?(c)

c.ascii_whitespace? || c.ord == -1

end

end

end