I ran into an issue today with fancy quotes in Lua source files. It appears the playdate compiler (pdc) is trying to be "helpful" by silently pre-processing “smart quote” characters translating them into regular double quotes.
As a result, using those utf-8 literals in a string literal ("chicken “salad” sandwich" in a Lua source file will generate a compile time error, despite it being correct Lua code. Womp womp.
The characters in question:
U+201C “ Left double curved quote (8220 in decimal)
U+201D ” Right double curved quote (8221 in decimal)
If anyone you want to use fancy quotes in your fonts, here's a workaround:
-- local text = "chicken “salad” sandwich"
local text = table.concat({
"chicken ",
utf8.char(8220), "salad", utf8.char(8221),
" sandwich"
})
font:drawText(text, 1, 1)
I'd love to see Panic deprecate this behavior of pdc and just throw an error when it encounters a raw smart quote when parsing (unless inside a string literal) like vanilla Lua. I also understand this is super-low priority and so likely won't change.
In trying to debug this character-by-character in the problematic strings I also discovered that Lua's string.sub(str, start, end) is not utf-8 aware so cannot directly be used to iterate character-by-character over non-ASCII strings.
Here is an example of how to properly iterate glyph-by-glyph in a UTF-8 string in lua:
function utf8_debug(str)
local n = 0
print("utf8_debug:", str)
print("pos", "byt", "chr", "codepoint")
print("---", "---", "---", "---------")
for p, c in utf8.codes(str) do
n = n + 1
print(n, p, utf8.char(c), string.format("U+%04x (%d)", c, c):upper())
end
end
text = table.concat({ utf8.char(8220), "\"' ", utf8.char(8221) })
utf8_debug(text)
