1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117

#![feature(test)]
// Copyright 2019 YechaoLi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#[macro_use]
extern crate lazy_static;

pub mod trim;

pub trait Prune: IsNone {
    fn prune(self) -> Self;
}

pub trait IsNone {
    fn is_none(&self) -> bool {
        false
    }
}

impl<T> IsNone for Option<T> {
    fn is_none(&self) -> bool {
        self.is_none()
    }
}

impl<T> Prune for Option<T>
where
    T: Prune + IsNone,
{
    fn prune(self) -> Self {
        match self {
            None => None,
            Some(s) => {
                let s = s.prune();
                if s.is_none() {
                    None
                } else {
                    Some(s)
                }
            }
        }
    }
}

impl<T> IsNone for Vec<T> {}

impl<T> Prune for Vec<T>
where
    T: Prune,
{
    fn prune(self) -> Self {
        self.into_iter().map(Prune::prune).collect()
    }
}

#[derive(Debug)]
pub enum Operator {
    Trim,
    TrimStart,
    TrimEnd,
    NoWhitespace,
    Nested,
    Custom(String),
}

macro_rules! tuple_impls {
    ($(
        ($(($idx:tt)),+)
    )+) => {
        tuple_impls! {
            $(
                ($((T, $idx)),+)
            )+
        }
    };
    ($(
        ($(($T:ident, $idx:tt)),+)
    )+) => {
        $(
            impl<T> IsNone for ($($T),+) {}

            impl<T> Prune for ($($T),+) where T: Prune {
                fn prune(self) -> Self {
                    (
                        $(self.$idx.prune()),+
                    )
                }
            }
        )+
    };
}

tuple_impls! {
    ((0), (1))
    ((0), (1), (2))
    ((0), (1), (2), (3))
    ((0), (1), (2), (3), (4))
    ((0), (1), (2), (3), (4), (5))
    ((0), (1), (2), (3), (4), (5), (6))
    ((0), (1), (2), (3), (4), (5), (6), (7))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12))
}