Add ParseCSV as lua function

processor/processor.go

@@ -189,24 +189,122 @@ end
 
 ---@param table table
 ---@param depth number?
-function DumpTable(table, depth)
+function dump(table, depth)
 	if depth == nil then
 		depth = 0
 	end
 	if (depth > 200) then
-		print("Error: Depth > 200 in dumpTable()")
+		print("Error: Depth > 200 in dump()")
 		return
 	end
 	for k, v in pairs(table) do
 		if (type(v) == "table") then
 			print(string.rep("  ", depth) .. k .. ":")
-			DumpTable(v, depth + 1)
+			dump(v, depth + 1)
 		else
 			print(string.rep("  ", depth) .. k .. ": ", v)
 		end
 	end
 end
 
+--- Parses CSV text into rows and fields using a minimal RFC 4180 state machine.
+---
+--- Requirements/assumptions:
+--- - Input is a single string containing the entire CSV content.
+--- - Field separators are commas (,).
+--- - Newlines between rows may be "\n" or "\r\n". "\r\n" is treated as one line break.
+--- - Fields may be quoted with double quotes (").
+--- - Inside quoted fields, doubled quotes ("") represent a literal quote character.
+--- - No backslash escaping is supported (not part of RFC 4180).
+--- - Newlines inside quoted fields are preserved as part of the field.
+--- - Leading/trailing spaces are preserved; no trimming is performed.
+--- - Empty fields and empty rows are preserved.
+--- - The final row is emitted even if the text does not end with a newline.
+---
+--- Returns:
+--- - A table (array) of rows; each row is a table (array) of string fields.
+local function parseCSV(csv)
+	local rows = {}
+	local fields = {}
+	local field = {}
+
+	local STATE_DEFAULT = 1
+	local STATE_IN_QUOTES = 2
+	local STATE_QUOTE_IN_QUOTES = 3
+	local state = STATE_DEFAULT
+
+	local i = 1
+	local len = #csv
+
+	while i <= len do
+		local c = csv:sub(i, i)
+
+		if state == STATE_DEFAULT then
+			if c == '"' then
+				state = STATE_IN_QUOTES
+				i = i + 1
+			elseif c == ',' then
+				table.insert(fields, table.concat(field))
+				field = {}
+				i = i + 1
+			elseif c == '\r' or c == '\n' then
+				table.insert(fields, table.concat(field))
+				field = {}
+				table.insert(rows, fields)
+				fields = {}
+				if c == '\r' and i < len and csv:sub(i + 1, i + 1) == '\n' then
+					i = i + 2
+				else
+					i = i + 1
+				end
+			else
+				table.insert(field, c)
+				i = i + 1
+			end
+		elseif state == STATE_IN_QUOTES then
+			if c == '"' then
+				state = STATE_QUOTE_IN_QUOTES
+				i = i + 1
+			else
+				table.insert(field, c)
+				i = i + 1
+			end
+		else -- STATE_QUOTE_IN_QUOTES
+			if c == '"' then
+				table.insert(field, '"')
+				state = STATE_IN_QUOTES
+				i = i + 1
+			elseif c == ',' then
+				table.insert(fields, table.concat(field))
+				field = {}
+				state = STATE_DEFAULT
+				i = i + 1
+			elseif c == '\r' or c == '\n' then
+				table.insert(fields, table.concat(field))
+				field = {}
+				table.insert(rows, fields)
+				fields = {}
+				state = STATE_DEFAULT
+				if c == '\r' and i < len and csv:sub(i + 1, i + 1) == '\n' then
+					i = i + 2
+				else
+					i = i + 1
+				end
+			else
+				state = STATE_DEFAULT
+				-- Don't increment i, reprocess character in DEFAULT state
+			end
+		end
+	end
+
+	if #field > 0 or #fields > 0 then
+		table.insert(fields, table.concat(field))
+		table.insert(rows, fields)
+	end
+
+	return rows
+end
+
 -- String to number conversion helper
 function num(str)
     return tonumber(str) or 0
@@ -519,25 +617,26 @@ func GetLuaFunctionsHelp() string {
 	return `Lua Functions Available in Global Environment:
 
 MATH FUNCTIONS:
-  min(a, b)           - Returns the minimum of two numbers
+  min(a, b)   - Returns the minimum of two numbers
-  max(a, b)           - Returns the maximum of two numbers
+  max(a, b)   - Returns the maximum of two numbers
-  round(x, n)         - Rounds x to n decimal places (default 0)
+  round(x, n) - Rounds x to n decimal places (default 0)
-  floor(x)            - Returns the floor of x
+  floor(x)    - Returns the floor of x
-  ceil(x)             - Returns the ceiling of x
+  ceil(x)     - Returns the ceiling of x
 
 STRING FUNCTIONS:
-  upper(s)            - Converts string to uppercase
+  upper(s)                - Converts string to uppercase
-  lower(s)            - Converts string to lowercase
+  lower(s)                - Converts string to lowercase
-  format(s, ...)      - Formats string using Lua string.format
+  format(s, ...)          - Formats string using Lua string.format
-  trim(s)             - Removes leading/trailing whitespace
+  trim(s)                 - Removes leading/trailing whitespace
   strsplit(inputstr, sep) - Splits string by separator (default: whitespace)
-  num(str)            - Converts string to number (returns 0 if invalid)
+  parseCSV(csv)           - Parses CSV text into rows of fields
-  str(num)            - Converts number to string
+  num(str)                - Converts string to number (returns 0 if invalid)
-  is_number(str)      - Returns true if string is numeric
+  str(num)                - Converts number to string
+  is_number(str)          - Returns true if string is numeric
 
 TABLE FUNCTIONS:
-  DumpTable(table, depth) - Prints table structure recursively
+  dump(table, depth) - Prints table structure recursively
-  isArray(t)          - Returns true if table is a sequential array
+  isArray(t)         - Returns true if table is a sequential array
 
 HTTP FUNCTIONS:
   fetch(url, options) - Makes HTTP request, returns response table
@@ -552,12 +651,12 @@ UTILITY FUNCTIONS:
   print(...)          - Prints arguments to Go logger
 
 EXAMPLES:
-  round(3.14159, 2)   -> 3.14
+  round(3.14159, 2)      -> 3.14
   strsplit("a,b,c", ",") -> {"a", "b", "c"}
-  upper("hello")      -> "HELLO"
+  upper("hello")         -> "HELLO"
-  min(5, 3)           -> 3
+  min(5, 3)              -> 3
-  num("123")          -> 123
+  num("123")             -> 123
-  is_number("abc")    -> false
+  is_number("abc")       -> false
   fetch("https://api.example.com/data")
   re("(\\w+)@(\\w+)", "user@domain.com") -> {"user@domain.com", "user", "domain.com"}`
 }