string_utils.mojo

from list import List

fn __string__mul__(input_string: String, n: Int) -> String:
	var result: String = ""
	for _ in range(n):
		result += input_string
	return result

fn rjust(input_string: String, width: Int, fillchar: String = " ") raises -> String:
	if len(fillchar) != 1:
		raise Error(" The fill character must be exactly one character long")
	let extra = width - len(input_string)
	return __string__mul__(fillchar, extra) + input_string

fn ljust(input_string: String, width: Int, fillchar: String = " ") raises -> String:
	if len(fillchar) != 1:
		raise Error(" The fill character must be exactly one character long")
	let extra = width - len(input_string)
	return input_string + __string__mul__(fillchar, extra)

fn endswith(input_string: String, suffix: String, start: Int = 0, owned end: Int = -1) raises -> Bool:
	if end == -1:
		end = len(input_string)
	if end < start:
		raise Error("The end index must be greater than or equal to the start index")
	if end - start < len(suffix):
		return False
	return input_string[end - len(suffix) : end] == suffix

fn trim(s: String, leading: String, trailing: String) -> String:
	var start = 0
	var end = len(s)
	while start < end and s[start] == leading:
		start += 1
	while end > start and s[end - 1] == trailing:
		end -= 1
	return s[start:end]

fn find(s: String, sub: String) -> Int:
	return find(s, sub, 0)

fn find(s: String, sub: String, start: Int) -> Int:
	let len = s.__len__()
	let sub_len = sub.__len__()
	for i in range(start, len - sub_len + 1):
		var is_match = True
		for j in range(sub_len):
			if s[i + j] != sub[j]:
				is_match = False
				break
		if is_match:
			return i
	return -1 

fn split_to_strings(s: String, sep: String) -> String: 
	var s1 = s
	var result = String() 
	var index = find(s1, sep, 0)
	while index >= 0:
		result += s1[0:index] + "\n"
		s1 = s1[index + len(sep):len(s1)]
		index = find(s1, sep, 0)
	if len(s1) > 0:
		result += s1
	return result

fn split(s: String, sep: String) -> List:
	var s1 = s
	var result: List = List()
	var index = find(s1, sep, 0)
	while index >= 0:
		result.append(s1[0:index])
		s1 = s1[index + len(sep):len(s1)]
		index = find(s1, sep, 0)
	if len(s1) > 0:
		result.append(s1)
	return result

fn remove_char(s: String, char: String) -> String:
	var result = String()
	if char.__len__() == 1:
		var c: String = ""
		for i in range(len(s)):
			c = s[i]
			if c != char:
				result += c
	return result

fn count_char(s: String, char: String) -> Int:
	var count = 0
	if char.__len__() == 1:
		for i in range(len(s)):
			if s[i] == char:
				count += 1
	return count

fn substr(s: String, start: Int, length: Int) -> String:
	return s[start:start+length]

fn substr(s: String, start: Int) -> String:
	let length = len(s) - start
	return s[start:start+length]

fn build_string(char: String, length: Int) -> String:
	var result = String()
	for _ in range(length):
		result += char
	return result