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pretty/common.lua
2017-12-11 11:04:11 +01:00

83 lines
2.1 KiB
Lua

--------------------------------------------------------------------------------
-- Enum
local enum_metatable = {
__tostring = function (e) return 'Enum:' .. e.name or 'Enum: no name' end,
__concat = function (a, b) return tostring(a) .. tostring(b) end,
}
local function enum (t)
local e = {}
for _, v in ipairs(t) do
e[v] = setmetatable({ name = v }, enum_metatable)
end
return e
end
--------------------------------------------------------------------------------
-- Unicode
local UNICODE_CHAR_PATTERN = '[\01-\127\192-\255][\128-\191]*'
local UNICODE_ZERO_WIDTH_CHARACTERS = {}
for i = 128, 191 do UNICODE_ZERO_WIDTH_CHARACTERS['\204'..string.char(i)] = true end
for i = 128, 175 do UNICODE_ZERO_WIDTH_CHARACTERS['\205'..string.char(i)] = true end
local function iterate_utf8_chars (str)
-- TODO: Detect invalid codepoints.
return str:gmatch(UNICODE_CHAR_PATTERN)
end
local function utf8_string_length (str)
assert(type(str) == 'string')
local len = 0
for char in iterate_utf8_chars(str) do
if not UNICODE_ZERO_WIDTH_CHARACTERS[char] then
len = len + 1
end
end
return len
end
--------------------------------------------------------------------------------
-- L utility
local function width_of_strings_in_l (l, start_i, stop_i)
-- Argument fixing and Error Checking
assert(type(l) == 'table')
local start_i, stop_i = start_i or 1, stop_i or #l
assert(type(start_i) == 'number')
assert(type(stop_i) == 'number')
-- Do stuff
local width = 0
for i = start_i, stop_i do
local item_width = 0
if type(l[i]) == 'string' then
item_width = utf8_string_length(l[i])
elseif l[i].est_width then
item_width = l[i].est_width
end
width = width + item_width
end
-- Return
return width
end
--------------------------------------------------------------------------------
return {
TABLE_TYPE = enum { 'EMPTY', 'SEQUENCE', 'STRING_MAP', 'PURE_MAP', 'MIXED', 'SET' },
DISPLAY = { HIDE = 1, SMALL = 2, INLINE = 3, EXPAND = 4 },
utf8_string_length = utf8_string_length,
width_of_strings_in_l = width_of_strings_in_l,
}