1+ -- https://github.com/Lautenschlager-id/prepdir/blob/master/init.lua
2+
3+ local prepdir
4+ do
5+ local format = string.format
6+ local gsub = string.gsub
7+ local match = string.match
8+ local sub = string.sub
9+ local rep = string.rep
10+
11+ local conditionalSymbols = {
12+ [' &' = " and"
13+ [' |' = " or"
14+ [' !' = " not "
15+ [" !=" = " ~="
16+ }
17+ local symbolReplace = " [&|!]=?"
18+
19+ local prefix = " ()\t *@#"
20+ local endOfLine = " \r ?\n ()"
21+ local expression = " ([%w_ %+%-%*/%[%]%(%){}&|!%.<>~='\" ]+)"
22+
23+ local tokenCallbacks = { }
24+ local tokenMatchers = {
25+ IF = prefix .. " IF " .. expression .. endOfLine ,
26+ ELIF = prefix .. " ELIF " .. expression .. endOfLine ,
27+ ELSE = prefix .. " ELSE" .. endOfLine ,
28+ ENDIF = prefix .. " ENDIF" .. endOfLine ,
29+ __NEXT = prefix .. " (%S+)"
30+ }
31+
32+ local READING_CHUNK , chunks = false
33+
34+ tokenCallbacks .IF = function (src , endPos )
35+ if READING_CHUNK then return end
36+
37+ local iniPos , condition , endPos = match (src , tokenMatchers .IF , endPos )
38+ if not iniPos then return end
39+
40+ READING_CHUNK = true
41+
42+ chunks [# chunks + 1 ] = {
43+ __len = 1 ,
44+ c = {
45+ [1 ] = {
46+ iniPos = iniPos ,
47+ endPos = endPos ,
48+ condition = condition
49+ }
50+ }
51+ }
52+
53+ return endPos
54+ end
55+
56+ tokenCallbacks .ELIF = function (src , endPos )
57+ if not READING_CHUNK then return end
58+
59+ local iniPos , condition , endPos = match (src , tokenMatchers .ELIF , endPos )
60+ assert (iniPos )
61+
62+ local chunk = chunks [# chunks ]
63+ chunk .__len = chunk .__len + 1
64+ chunk .c [chunk .__len ] = {
65+ iniPos = iniPos ,
66+ endPos = endPos ,
67+ condition = condition
68+ }
69+
70+ return endPos
71+ end
72+
73+ tokenCallbacks .ELSE = function (src , endPos )
74+ if not READING_CHUNK then return end
75+
76+ local iniPos , endPos = match (src , tokenMatchers .ELSE , endPos )
77+ assert (iniPos )
78+
79+ local chunk = chunks [# chunks ]
80+ chunk .__len = chunk .__len + 1
81+ chunk .c [chunk .__len ] = {
82+ iniPos = iniPos ,
83+ endPos = endPos ,
84+ condition = " true"
85+ }
86+
87+ return endPos
88+ end
89+
90+ tokenCallbacks .ENDIF = function (src , endPos )
91+ if not READING_CHUNK then return end
92+
93+ local iniPos , endPos = match (src , tokenMatchers .ENDIF , endPos )
94+ if not iniPos then return end
95+
96+ READING_CHUNK = false
97+
98+ local chunk = chunks [# chunks ]
99+ chunk .c .endif = {
100+ iniPos = iniPos ,
101+ endPos = endPos
102+ }
103+
104+ return endPos
105+ end
106+
107+ tokenCallbacks .__NEXT = function (src , endPos )
108+ local iniPos , token = match (src , tokenMatchers .__NEXT , endPos )
109+ if not iniPos then return end
110+
111+ return token
112+ end
113+
114+ local parser = function (src )
115+ READING_CHUNK , chunks = false , { }
116+
117+ local endPos , ifPos
118+ repeat
119+ -- Opens the conditional
120+ endPos = tokenCallbacks .IF (src , endPos )
121+ if not endPos then
122+ break
123+ end
124+ ifPos = endPos
125+
126+ -- Gets all sub conditionals
127+ local nextToken
128+ repeat
129+ nextToken = tokenCallbacks .__NEXT (src , endPos )
130+ if nextToken == " ELIF" then
131+ endPos = tokenCallbacks .ELIF (src , endPos )
132+ else
133+ break
134+ end
135+ until false
136+
137+ -- Check of else
138+ if nextToken == " ELSE" then
139+ endPos = tokenCallbacks .ELSE (src , endPos )
140+ nextToken = nil
141+ end
142+
143+ -- Finish conditional
144+ nextToken = nextToken or tokenCallbacks .__NEXT (src , endPos )
145+ if nextToken ~= " ENDIF" then
146+ error (string.format (" [PREPDIR] @[%d:] Mandatory token ENDIF to close \z
147+ token IF in @[%d]" , endPos , ifPos ))
148+ end
149+ endPos = tokenCallbacks .ENDIF (src , endPos )
150+ until false
151+
152+ local cc
153+ for c = 1 , # chunks do
154+ c = chunks [c ]
155+ cc = c .c
156+ for sc = 1 , c .__len do
157+ sc = cc [sc ]
158+ sc .condition = gsub (sc .condition , symbolReplace , conditionalSymbols )
159+ end
160+ end
161+ end
162+
163+ local evaluateCondition = function (condition , settings )
164+ return load (" return " .. condition , ' ' ' t' settings )()
165+ end
166+
167+ local sliceString = function (str , boundaries )
168+ assert (# boundaries % 2 == 0 )
169+
170+ for b = # boundaries , 1 , - 2 do
171+ local _ , totalLines = gsub (sub (str , boundaries [b - 1 ], boundaries [b ] - 1 ), ' \n ' ' '
172+ str = sub (str , 1 , boundaries [b - 1 ] - 1 ) .. rep (' \n ' totalLines ) .. sub (str , boundaries [b ])
173+ end
174+
175+ return str
176+ end
177+
178+ local matcher = function (src , settings )
179+ local boundaries , totalBoundaries = { }, 0
180+
181+ local cc , scObj
182+ for c = 1 , # chunks do
183+ c = chunks [c ]
184+ cc = c .c
185+
186+ totalBoundaries = totalBoundaries + 1
187+ boundaries [totalBoundaries ] = cc [1 ].iniPos
188+
189+ for sc = 1 , c .__len do
190+ scObj = cc [sc ]
191+ if evaluateCondition (scObj .condition , settings ) then
192+ totalBoundaries = totalBoundaries + 1
193+ boundaries [totalBoundaries ] = scObj .endPos
194+
195+ totalBoundaries = totalBoundaries + 1
196+ boundaries [totalBoundaries ] = (cc [sc + 1 ] or cc .endif ).iniPos
197+ break
198+ end
199+ end
200+
201+ totalBoundaries = totalBoundaries + 1
202+ boundaries [totalBoundaries ] = cc .endif .endPos
203+ end
204+
205+ return sliceString (src , boundaries )
206+ end
207+
208+ prepdir = function (src , settings )
209+ -- Retrieve
210+ src = src .. " \n " -- For pattern matching
211+
212+ -- Get chunks
213+ parser (src )
214+
215+ src = matcher (src , settings )
216+
217+ return sub (src , 1 , - 2 )
218+ end
219+ end
220+
221+ return prepdir
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