Mon, 27 Jul 2009 03:26:17 +0100
minify: Add debug level, add warnings when specified level not valid, don't override options with defaults
1 | 1 | --[[-------------------------------------------------------------------- |
2 | ||
3 | llex.lua: Lua 5.1 lexical analyzer in Lua | |
4 | This file is part of LuaSrcDiet, based on Yueliang material. | |
5 | ||
6 | Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net> | |
7 | The COPYRIGHT file describes the conditions | |
8 | under which this software may be distributed. | |
9 | ||
10 | See the ChangeLog for more information. | |
11 | ||
12 | ----------------------------------------------------------------------]] | |
13 | ||
14 | --[[-------------------------------------------------------------------- | |
15 | -- NOTES: | |
16 | -- * This is a version of the native 5.1.x lexer from Yueliang 0.4.0, | |
17 | -- with significant modifications to handle LuaSrcDiet's needs: | |
18 | -- (1) llex.error is an optional error function handler | |
19 | -- (2) seminfo for strings include their delimiters and no | |
20 | -- translation operations are performed on them | |
21 | -- * ADDED shbang handling has been added to support executable scripts | |
22 | -- * NO localized decimal point replacement magic | |
23 | -- * NO limit to number of lines | |
24 | -- * NO support for compatible long strings (LUA_COMPAT_LSTR) | |
25 | -- * Please read technotes.txt for more technical details. | |
26 | ----------------------------------------------------------------------]] | |
27 | ||
28 | local base = _G | |
29 | local string = require "string" | |
30 | module "llex" | |
31 | ||
32 | local find = string.find | |
33 | local match = string.match | |
34 | local sub = string.sub | |
35 | ||
36 | ---------------------------------------------------------------------- | |
37 | -- initialize keyword list, variables | |
38 | ---------------------------------------------------------------------- | |
39 | ||
40 | local kw = {} | |
41 | for v in string.gmatch([[ | |
42 | and break do else elseif end false for function if in | |
43 | local nil not or repeat return then true until while]], "%S+") do | |
44 | kw[v] = true | |
45 | end | |
46 | ||
47 | -- NOTE: see init() for module variables (externally visible): | |
48 | -- tok, seminfo, tokln | |
49 | ||
50 | local z, -- source stream | |
51 | sourceid, -- name of source | |
52 | I, -- position of lexer | |
53 | buff, -- buffer for strings | |
54 | ln -- line number | |
55 | ||
56 | ---------------------------------------------------------------------- | |
57 | -- add information to token listing | |
58 | ---------------------------------------------------------------------- | |
59 | ||
60 | local function addtoken(token, info) | |
61 | local i = #tok + 1 | |
62 | tok[i] = token | |
63 | seminfo[i] = info | |
64 | tokln[i] = ln | |
65 | end | |
66 | ||
67 | ---------------------------------------------------------------------- | |
68 | -- handles line number incrementation and end-of-line characters | |
69 | ---------------------------------------------------------------------- | |
70 | ||
71 | local function inclinenumber(i, is_tok) | |
72 | local sub = sub | |
73 | local old = sub(z, i, i) | |
74 | i = i + 1 -- skip '\n' or '\r' | |
75 | local c = sub(z, i, i) | |
76 | if (c == "\n" or c == "\r") and (c ~= old) then | |
77 | i = i + 1 -- skip '\n\r' or '\r\n' | |
78 | old = old..c | |
79 | end | |
80 | if is_tok then addtoken("TK_EOL", old) end | |
81 | ln = ln + 1 | |
82 | I = i | |
83 | return i | |
84 | end | |
85 | ||
86 | ---------------------------------------------------------------------- | |
87 | -- initialize lexer for given source _z and source name _sourceid | |
88 | ---------------------------------------------------------------------- | |
89 | ||
90 | function init(_z, _sourceid) | |
91 | z = _z -- source | |
92 | sourceid = _sourceid -- name of source | |
93 | I = 1 -- lexer's position in source | |
94 | ln = 1 -- line number | |
95 | tok = {} -- lexed token list* | |
96 | seminfo = {} -- lexed semantic information list* | |
97 | tokln = {} -- line numbers for messages* | |
98 | -- (*) externally visible thru' module | |
99 | -------------------------------------------------------------------- | |
100 | -- initial processing (shbang handling) | |
101 | -------------------------------------------------------------------- | |
102 | local p, _, q, r = find(z, "^(#[^\r\n]*)(\r?\n?)") | |
103 | if p then -- skip first line | |
104 | I = I + #q | |
105 | addtoken("TK_COMMENT", q) | |
106 | if #r > 0 then inclinenumber(I, true) end | |
107 | end | |
108 | end | |
109 | ||
110 | ---------------------------------------------------------------------- | |
111 | -- returns a chunk name or id, no truncation for long names | |
112 | ---------------------------------------------------------------------- | |
113 | ||
114 | function chunkid() | |
115 | if sourceid and match(sourceid, "^[=@]") then | |
116 | return sub(sourceid, 2) -- remove first char | |
117 | end | |
118 | return "[string]" | |
119 | end | |
120 | ||
121 | ---------------------------------------------------------------------- | |
122 | -- formats error message and throws error | |
123 | -- * a simplified version, does not report what token was responsible | |
124 | ---------------------------------------------------------------------- | |
125 | ||
126 | function errorline(s, line) | |
127 | local e = error or base.error | |
128 | e(string.format("%s:%d: %s", chunkid(), line or ln, s)) | |
129 | end | |
130 | local errorline = errorline | |
131 | ||
132 | ------------------------------------------------------------------------ | |
133 | -- count separators ("=") in a long string delimiter | |
134 | ------------------------------------------------------------------------ | |
135 | ||
136 | local function skip_sep(i) | |
137 | local sub = sub | |
138 | local s = sub(z, i, i) | |
139 | i = i + 1 | |
140 | local count = #match(z, "=*", i) -- note, take the length | |
141 | i = i + count | |
142 | I = i | |
143 | return (sub(z, i, i) == s) and count or (-count) - 1 | |
144 | end | |
145 | ||
146 | ---------------------------------------------------------------------- | |
147 | -- reads a long string or long comment | |
148 | ---------------------------------------------------------------------- | |
149 | ||
150 | local function read_long_string(is_str, sep) | |
151 | local i = I + 1 -- skip 2nd '[' | |
152 | local sub = sub | |
153 | local c = sub(z, i, i) | |
154 | if c == "\r" or c == "\n" then -- string starts with a newline? | |
155 | i = inclinenumber(i) -- skip it | |
156 | end | |
157 | local j = i | |
158 | while true do | |
159 | local p, q, r = find(z, "([\r\n%]])", i) -- (long range) | |
160 | if not p then | |
161 | errorline(is_str and "unfinished long string" or | |
162 | "unfinished long comment") | |
163 | end | |
164 | i = p | |
165 | if r == "]" then -- delimiter test | |
166 | if skip_sep(i) == sep then | |
167 | buff = sub(z, buff, I) | |
168 | I = I + 1 -- skip 2nd ']' | |
169 | return buff | |
170 | end | |
171 | i = I | |
172 | else -- newline | |
173 | buff = buff.."\n" | |
174 | i = inclinenumber(i) | |
175 | end | |
176 | end--while | |
177 | end | |
178 | ||
179 | ---------------------------------------------------------------------- | |
180 | -- reads a string | |
181 | ---------------------------------------------------------------------- | |
182 | ||
183 | local function read_string(del) | |
184 | local i = I | |
185 | local find = find | |
186 | local sub = sub | |
187 | while true do | |
188 | local p, q, r = find(z, "([\n\r\\\"\'])", i) -- (long range) | |
189 | if p then | |
190 | if r == "\n" or r == "\r" then | |
191 | errorline("unfinished string") | |
192 | end | |
193 | i = p | |
194 | if r == "\\" then -- handle escapes | |
195 | i = i + 1 | |
196 | r = sub(z, i, i) | |
197 | if r == "" then break end -- (EOZ error) | |
198 | p = find("abfnrtv\n\r", r, 1, true) | |
199 | ------------------------------------------------------ | |
200 | if p then -- special escapes | |
201 | if p > 7 then | |
202 | i = inclinenumber(i) | |
203 | else | |
204 | i = i + 1 | |
205 | end | |
206 | ------------------------------------------------------ | |
207 | elseif find(r, "%D") then -- other non-digits | |
208 | i = i + 1 | |
209 | ------------------------------------------------------ | |
210 | else -- \xxx sequence | |
211 | local p, q, s = find(z, "^(%d%d?%d?)", i) | |
212 | i = q + 1 | |
213 | if s + 1 > 256 then -- UCHAR_MAX | |
214 | errorline("escape sequence too large") | |
215 | end | |
216 | ------------------------------------------------------ | |
217 | end--if p | |
218 | else | |
219 | i = i + 1 | |
220 | if r == del then -- ending delimiter | |
221 | I = i | |
222 | return sub(z, buff, i - 1) -- return string | |
223 | end | |
224 | end--if r | |
225 | else | |
226 | break -- (error) | |
227 | end--if p | |
228 | end--while | |
229 | errorline("unfinished string") | |
230 | end | |
231 | ||
232 | ------------------------------------------------------------------------ | |
233 | -- main lexer function | |
234 | ------------------------------------------------------------------------ | |
235 | ||
236 | function llex() | |
237 | local find = find | |
238 | local match = match | |
239 | while true do--outer | |
240 | local i = I | |
241 | -- inner loop allows break to be used to nicely section tests | |
242 | while true do--inner | |
243 | ---------------------------------------------------------------- | |
244 | local p, _, r = find(z, "^([_%a][_%w]*)", i) | |
245 | if p then | |
246 | I = i + #r | |
247 | if kw[r] then | |
248 | addtoken("TK_KEYWORD", r) -- reserved word (keyword) | |
249 | else | |
250 | addtoken("TK_NAME", r) -- identifier | |
251 | end | |
252 | break -- (continue) | |
253 | end | |
254 | ---------------------------------------------------------------- | |
255 | local p, _, r = find(z, "^(%.?)%d", i) | |
256 | if p then -- numeral | |
257 | if r == "." then i = i + 1 end | |
258 | local _, q, r = find(z, "^%d*[%.%d]*([eE]?)", i) | |
259 | i = q + 1 | |
260 | if #r == 1 then -- optional exponent | |
261 | if match(z, "^[%+%-]", i) then -- optional sign | |
262 | i = i + 1 | |
263 | end | |
264 | end | |
265 | local _, q = find(z, "^[_%w]*", i) | |
266 | I = q + 1 | |
267 | local v = sub(z, p, q) -- string equivalent | |
268 | if not base.tonumber(v) then -- handles hex test also | |
269 | errorline("malformed number") | |
270 | end | |
271 | addtoken("TK_NUMBER", v) | |
272 | break -- (continue) | |
273 | end | |
274 | ---------------------------------------------------------------- | |
275 | local p, q, r, t = find(z, "^((%s)[ \t\v\f]*)", i) | |
276 | if p then | |
277 | if t == "\n" or t == "\r" then -- newline | |
278 | inclinenumber(i, true) | |
279 | else | |
280 | I = q + 1 -- whitespace | |
281 | addtoken("TK_SPACE", r) | |
282 | end | |
283 | break -- (continue) | |
284 | end | |
285 | ---------------------------------------------------------------- | |
286 | local r = match(z, "^%p", i) | |
287 | if r then | |
288 | buff = i | |
289 | local p = find("-[\"\'.=<>~", r, 1, true) | |
290 | if p then | |
291 | -- two-level if block for punctuation/symbols | |
292 | -------------------------------------------------------- | |
293 | if p <= 2 then | |
294 | if p == 1 then -- minus | |
295 | local c = match(z, "^%-%-(%[?)", i) | |
296 | if c then | |
297 | i = i + 2 | |
298 | local sep = -1 | |
299 | if c == "[" then | |
300 | sep = skip_sep(i) | |
301 | end | |
302 | if sep >= 0 then -- long comment | |
303 | addtoken("TK_LCOMMENT", read_long_string(false, sep)) | |
304 | else -- short comment | |
305 | I = find(z, "[\n\r]", i) or (#z + 1) | |
306 | addtoken("TK_COMMENT", sub(z, buff, I - 1)) | |
307 | end | |
308 | break -- (continue) | |
309 | end | |
310 | -- (fall through for "-") | |
311 | else -- [ or long string | |
312 | local sep = skip_sep(i) | |
313 | if sep >= 0 then | |
314 | addtoken("TK_LSTRING", read_long_string(true, sep)) | |
315 | elseif sep == -1 then | |
316 | addtoken("TK_OP", "[") | |
317 | else | |
318 | errorline("invalid long string delimiter") | |
319 | end | |
320 | break -- (continue) | |
321 | end | |
322 | -------------------------------------------------------- | |
323 | elseif p <= 5 then | |
324 | if p < 5 then -- strings | |
325 | I = i + 1 | |
326 | addtoken("TK_STRING", read_string(r)) | |
327 | break -- (continue) | |
328 | end | |
329 | r = match(z, "^%.%.?%.?", i) -- .|..|... dots | |
330 | -- (fall through) | |
331 | -------------------------------------------------------- | |
332 | else -- relational | |
333 | r = match(z, "^%p=?", i) | |
334 | -- (fall through) | |
335 | end | |
336 | end | |
337 | I = i + #r | |
338 | addtoken("TK_OP", r) -- for other symbols, fall through | |
339 | break -- (continue) | |
340 | end | |
341 | ---------------------------------------------------------------- | |
342 | local r = sub(z, i, i) | |
343 | if r ~= "" then | |
344 | I = i + 1 | |
345 | addtoken("TK_OP", r) -- other single-char tokens | |
346 | break | |
347 | end | |
348 | addtoken("TK_EOS", "") -- end of stream, | |
349 | return -- exit here | |
350 | ---------------------------------------------------------------- | |
351 | end--while inner | |
352 | end--while outer | |
353 | end | |
354 | ||
355 | return base.getfenv() |