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kraken/stdlib/regex.krak

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import io
import vector
import string
fun regex(in: char*):regex {
return regex(string::string(in))
}
fun regex(in: string::string):regex {
var out.construct(in):regex
return out
}
obj regexState(Object) {
var character: char
var next_states: vector::vector<regexState*>
fun construct(charIn:char): regexState* {
character = charIn
next_states.construct()
return this
}
fun construct(): regexState* {
return construct(0)
}
fun copy_construct(old:regexState*): void {
character = regexState->character
next_states.copy_construct(&regexState->next_states)
}
fun destruct():void {
next_states.destruct()
}
fun match(input: char): vector::vector<regexState*> {
return next_states.filter(fun(it:regexState*):bool { return it->character == input; } )
}
}
obj regex(Object) {
var regexString: string::string
var begin: regexState
fun construct(regexStringIn: string::string): regex* {
regexState.construct()
regexString.copy_construct(&regexStringIn)
var traverse = &begin
for (var i = 0; i < regexString.length(); i++;) {
var next = new<regexState>()->construct(regexString[i])
traverse->next_states->add(next)
traverse = next
}
traverse->next_states->add(new<regexState>()->construct(1))
return this
}
fun copy_construct(old:regex*):void {
begin.copy_construct(&old->begin)
regexString.copy_construct(&old->regexString)
}
fun destruct():void {
begin.destruct()
regexString.destruct()
}
fun long_match(to_match: char*): int { return long_match(string::string(to_match)); }
fun long_match(to_match: string::string): int {
var next = vector::vector(&begin)
var longest = 0
for (var i = 0; i < to_match.length(); i++;) {
if (next.size == 0)
return longest
if (next.any_true(fun(state: regexState*):bool { return state->character == 1; }))
longest = i
next = next.flatten_map(fun(state: regexState*): vector::vector<regexState*> { return state->match(to_match[i]); })
}
if (next.any_true(fun(state: regexState*):bool { return state->character == 1; }))
return to_match.length()
return longest
}
}