77 lines
2.1 KiB
Plaintext
77 lines
2.1 KiB
Plaintext
include "List.aes"
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namespace Option =
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function is_none(o : option('a)) : bool = switch(o)
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None => true
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Some(_) => false
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function is_some(o : option('a)) : bool = switch(o)
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None => false
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Some(_) => true
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function match(n : 'b, s : 'a => 'b, o : option('a)) : 'b = switch(o)
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None => n
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Some(x) => s(x)
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function default(def : 'a, o : option('a)) : 'a = match(def, (x) => x, o)
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function force(o : option('a)) : 'a = default(abort("Forced None value"), o)
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function on_elem(o : option('a), f : 'a => unit) : unit = match((), f, o)
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function map(f : 'a => 'b, o : option('a)) : option('b) = switch(o)
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None => None
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Some(x) => Some(f(x))
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function map2(f : ('a, 'b) => 'c
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, o1 : option('a)
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, o2 : option('b)
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) : option('c) = switch((o1, o2))
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(Some(x1), Some(x2)) => Some(f(x1, x2))
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_ => None
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function map3( f : ('a, 'b, 'c) => 'd
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, o1 : option('a)
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, o2 : option('b)
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, o3 : option('c)
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) : option('d) = switch((o1, o2, o3))
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(Some(x1), Some(x2), Some(x3)) => Some(f(x1, x2, x3))
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_ => None
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function app_over(f : option ('a => 'b), o : option('a)) : option('b) = switch((f, o))
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(Some(ff), Some(xx)) => Some(ff(xx))
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_ => None
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function flat_map(f : 'a => option('b), o : option('a)) : option('b) = switch(o)
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None => None
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Some(x) => f(x)
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function to_list(o : option('a)) : list('a) = switch(o)
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None => []
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Some(x) => [x]
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function filter_options(l : list(option('a))) : list('a) = switch(l)
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[] => []
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None::t => filter_options(t)
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Some(x)::t => x::filter_options(t)
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function seq_options(l : list (option('a))) : option (list('a)) = switch(l)
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[] => Some([])
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None::_ => None
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Some(x)::t => switch(seq_options(t))
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None => None
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Some(st) => Some(x::st)
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function choose(o1 : option('a), o2 : option('a)) : option('a) =
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if(is_some(o1)) o1 else o2
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function choose_first(l : list(option('a))) : option('a) = switch(l)
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[] => None
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None::t => choose_first(t)
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Some(x)::_ => Some(x)
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