Initial commit
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4DBug
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if _G.__IMGUI_ENV then setfenv(1, _G.__IMGUI_ENV) end -- [Roblox] shared env, see init.lua
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--- ImGui Sincerely
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-- This is a minimal Lua impl of C-like sscanf, sprintf sub-set
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-- Supports:
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-- - %x, %X, %nx, %nX (where n is a number)
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-- - %d, %nd (where n is a number)
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-- - %f, %lf (very limited)
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--
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-- Returns items_matched instead of EOF on error
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local _byte = string.byte
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local CHAR_PERCENT = _byte'%'
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local CHAR_DOT = _byte'.'
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local CHAR_PLUS, CHAR_MINUS = _byte'+', _byte'-'
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local CHAR_0, CHAR_9 = _byte'0', _byte'9'
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local CHAR_a, CHAR_A = _byte'a', _byte'A'
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local CHAR_d = _byte'd'
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local CHAR_l = _byte'l'
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local CHAR_f, CHAR_F = _byte'f', _byte'F'
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local CHAR_x, CHAR_X = _byte'x', _byte'X'
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local function isspace(c) return c == 32 or c == 9 end
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local function isdigit(c) return c >= CHAR_0 and c <= CHAR_9 end
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local function isxdigit(c) return isdigit(c) or (c >= CHAR_a and c <= CHAR_f) or (c >= CHAR_A and c <= CHAR_F) end
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local function isdigit_under_base(c, base)
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if base == 10 then return isdigit(c)
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elseif base == 16 then return isxdigit(c)
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end
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end
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local function hex_digit_to_int(c)
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if c >= CHAR_0 and c <= CHAR_9 then return c - CHAR_0 end
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if c >= CHAR_a and c <= CHAR_f then return c - CHAR_a + 10 end
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if c >= CHAR_A and c <= CHAR_F then return c - CHAR_A + 10 end
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end
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-- we force this behavior by default
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local function clamp_if_overflow(spec, val)
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if spec == CHAR_d or spec == CHAR_x or spec == CHAR_X then
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if val > INT_MAX then return INT_MAX end
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if val < INT_MIN then return INT_MIN end
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end
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return val
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end
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--- @param buffer char[]
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--- @param buffer_begin int
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--- @param format string
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--- @param result table # table to store parsed values
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local function sscanf(buffer, buffer_begin, format, result)
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local p = buffer_begin
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local f = 1 -- format_begin
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local format_len = #format
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local assigned = 0
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local items_matched = 0
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while f <= format_len do
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repeat
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if isspace(_byte(format, f, f)) then
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while isspace(buffer[p]) do
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p = p + 1
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end
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f = f + 1
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break
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end
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if _byte(format, f, f) ~= CHAR_PERCENT then
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if buffer[p] == _byte(format, f, f) then
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p = p + 1
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f = f + 1
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else
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return items_matched
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end
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break
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end
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-- encountered % in fmt
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f = f + 1
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-- %%
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if _byte(format, f, f) == CHAR_PERCENT then
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if buffer[p] == CHAR_PERCENT then
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p = p + 1
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f = f + 1
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else
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return items_matched
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end
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break
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end
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-- handle optional width
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local width = 0
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while isdigit(_byte(format, f, f)) do
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width = width * 10 + _byte(format, f, f) - CHAR_0
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f = f + 1
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end
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if width == 0 then
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width = math.huge
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end
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local spec = _byte(format, f, f)
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local base
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local is_float = false
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if spec == CHAR_x or spec == CHAR_X then
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base = 16
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elseif spec == CHAR_d then
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base = 10
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elseif spec == CHAR_f or spec == CHAR_F then
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is_float = true
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elseif spec == CHAR_l then
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f = f + 1
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if _byte(format, f, f) == CHAR_f then
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is_float = true -- TODO: distinguish from float?
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else
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return items_matched
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end
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else
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return items_matched
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end
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f = f + 1
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while isspace(buffer[p]) do
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p = p + 1
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end
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local val
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if is_float then
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local sign = 1
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if buffer[p] == CHAR_PLUS then
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p = p + 1
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elseif buffer[p] == CHAR_MINUS then
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sign = -1
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p = p + 1
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end
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-- inf, nan are not handled
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local p_start = p
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local int_part = 0
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while isdigit(buffer[p]) do
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int_part = int_part * 10 + (buffer[p] - CHAR_0)
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p = p + 1
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end
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local frac_part = 0
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local frac_div = 1
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if buffer[p] == CHAR_DOT then
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p = p + 1
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while isdigit(buffer[p]) do
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frac_part = frac_part * 10 + (buffer[p] - CHAR_0)
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frac_div = frac_div * 10
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p = p + 1
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end
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end
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if p == p_start then
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return items_matched
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end
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val = sign * (int_part + frac_part / frac_div)
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else
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local sign = 1
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-- optional sign
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if base == 10 then
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if buffer[p] == CHAR_PLUS then
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p = p + 1
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width = width - 1
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elseif buffer[p] == CHAR_MINUS then
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sign = -1
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p = p + 1
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width = width - 1
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end
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end
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local p_start = p
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while width > 0 and buffer[p] and isdigit_under_base(buffer[p], base) do
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p = p + 1
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width = width - 1
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end
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if p == p_start then
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-- failed to match
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return items_matched
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end
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val = 0
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while p_start < p do
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local c = buffer[p_start]
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p_start = p_start + 1
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val = val * base + sign * hex_digit_to_int(c)
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local old_val = val
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val = clamp_if_overflow(spec, val)
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if old_val ~= val then
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break
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end
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end
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end
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result[assigned + 1] = val
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assigned = assigned + 1
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items_matched = items_matched + 1
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until true
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end
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return items_matched
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end
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local function sprintf()
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end
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return sscanf
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