csv.lua@0e2b5dc7ae34 (annotated)
csv.lua
Fri, 26 Mar 2010 01:30:24 +0000
- author
- Matthew Wild <mwild1@gmail.com>
- date
- Fri, 26 Mar 2010 01:30:24 +0000
- changeset 0
- 0e2b5dc7ae34
- child 3
- 5b24d66365ec
- permissions
- -rw-r--r--
Initial commit
| 0 | 1 | |
| 2 | local lpeg = require "lpeg" | |
| 3 | local setmetatable, tonumber = | |
| 4 | setmetatable, tonumber; | |
| 5 | local s_char = string.char; | |
| 6 | ||
| 7 | module("csv"); | |
| 8 | ||
| 9 | local delim = lpeg.P","; | |
| 10 | ||
| 11 | local char_escape = lpeg.R"az" + lpeg.S"\\\r\n" + delim; | |
| 12 | local numeric_escape = (lpeg.R"09"^1)^-3; | |
| 13 | local escape = (lpeg.P"\\" * (char_escape + numeric_escape)); | |
| 14 | ||
| 15 | local value = (escape + (1-delim))^0; | |
| 16 | ||
| 17 | local escape_map = setmetatable({ | |
| 18 | t = "\t", b = "\b", f = "\f"; | |
| 19 | n = "\n", r = "\r", v = "\v"; }, | |
| 20 | { __index = function (_, n) | |
| 21 | if tonumber(n) then | |
| 22 | print"n" | |
| 23 | return s_char(tonumber(n)); | |
| 24 | else | |
| 25 | return n; | |
| 26 | end | |
| 27 | end | |
| 28 | }); | |
| 29 | ||
| 30 | function read_record(line, value_callback) | |
| 31 | local fieldpos = 0; | |
| 32 | local callback = function (v) | |
| 33 | return value_callback(v:gsub("\\(.)", escape_map)); | |
| 34 | end; | |
| 35 | repeat | |
| 36 | fieldpos = lpeg.match(value / callback, line, fieldpos+1); | |
| 37 | until fieldpos >= #line; | |
| 38 | end | |
| 39 | ||
| 40 | return _M; |
