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local _
local alpha = {}
_ = string.gsub('abcdefghijklmnopqrstuvwxyz', '.', function(char)
alpha[string.byte(char)] = true
end)
local ALPHA = {}
_ = string.gsub('ABCDEFGHIJKLMNOPQRSTUVWXYZ', '.', function(char)
ALPHA[string.byte(char)] = true
end)
local digit = {}
_ = string.gsub('1234567890', '.', function(char)
digit[string.byte(char)] = true
end)
local white = {}
_ = string.gsub(' \t\n', '.', function(char)
white[string.byte(char)] = true
end)
local char = {}
---@param byte integer
---@return boolean
char.is_upper = function(byte)
return ALPHA[byte]
end
---@param byte integer
---@return boolean
char.is_alpha = function(byte)
return alpha[byte] or ALPHA[byte]
end
---@param byte integer
---@return boolean
char.is_digit = function(byte)
return digit[byte]
end
---@param byte integer
---@return boolean
char.is_white = function(byte)
return white[byte]
end
---@param byte integer
---@return boolean
char.is_symbol = function(byte)
return not (char.is_alnum(byte) or char.is_white(byte))
end
---@param byte integer
---@return boolean
char.is_printable = function(byte)
return string.match(string.char(byte), '^%c$') == nil
end
---@param byte integer
---@return boolean
char.is_alnum = function(byte)
return char.is_alpha(byte) or char.is_digit(byte)
end
---@param text string
---@param index integer
---@return boolean
char.is_semantic_index = function(text, index)
if index <= 1 then
return true
end
local prev = string.byte(text, index - 1)
local curr = string.byte(text, index)
if not char.is_upper(prev) and char.is_upper(curr) then
return true
end
if char.is_symbol(curr) or char.is_white(curr) then
return true
end
if not char.is_alpha(prev) and char.is_alpha(curr) then
return true
end
if not char.is_digit(prev) and char.is_digit(curr) then
return true
end
return false
end
---@param text string
---@param current_index integer
---@return integer
char.get_next_semantic_index = function(text, current_index)
for i = current_index + 1, #text do
if char.is_semantic_index(text, i) then
return i
end
end
return #text + 1
end
---Ignore case match
---@param byte1 integer
---@param byte2 integer
---@return boolean
char.match = function(byte1, byte2)
if not char.is_alpha(byte1) or not char.is_alpha(byte2) then
return byte1 == byte2
end
local diff = byte1 - byte2
return diff == 0 or diff == 32 or diff == -32
end
return char
|
