-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
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-- AWK LPeg lexer.
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-- Modified by Wolfgang Seeberg 2012, 2013.
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local lexer = require('lexer')
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local token, word_match = lexer.token, lexer.word_match
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local P, R, S = lpeg.P, lpeg.R, lpeg.S
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local lex = lexer.new('awk')
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local LEFTBRACKET = '['
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local RIGHTBRACKET = ']'
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local SLASH = '/'
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local BACKSLASH = '\\'
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local CARET = '^'
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local CR = '\r'
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local LF = '\n'
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local CRLF = CR .. LF
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local DQUOTE = '"'
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local DELIMITER_MATCHES = {['('] = ')', ['['] = ']'}
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local COMPANION = {['('] = '[', ['['] = '('}
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local CC = {
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alnum = 1, alpha = 1, blank = 1, cntrl = 1, digit = 1, graph = 1, lower = 1,
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print = 1, punct = 1, space = 1, upper = 1, xdigit = 1
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}
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local LastRegexEnd = 0
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local BackslashAtCommentEnd = 0
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local KW_BEFORE_RX = {
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case = 1, ['do'] = 1, ['else'] = 1, exit = 1, print = 1, printf = 1,
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['return'] = 1
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}
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local function findKeyword(input, e)
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local i = e
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while i > 0 and input:find("^[%l]", i) do i = i - 1 end
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local w = input:sub(i + 1, e)
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if i == 0 then
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return KW_BEFORE_RX[w] == 1
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elseif input:find("^[%u%d_]", i) then
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return false
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else
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return KW_BEFORE_RX[w] == 1
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end
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end
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local function isRegex(input, i)
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while i >= 1 and input:find('^[ \t]', i) do i = i - 1 end
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if i < 1 then return true end
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if input:find("^[-!%%&(*+,:;<=>?[^{|}~\f]", i) or findKeyword(input, i) then
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return true
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elseif input:sub(i, i) == SLASH then
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return i ~= LastRegexEnd -- deals with /xx/ / /yy/.
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elseif input:find('^[]%w)."]', i) then
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return false
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elseif input:sub(i, i) == LF then
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if i == 1 then return true end
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i = i - 1
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if input:sub(i, i) == CR then
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if i == 1 then return true end
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i = i - 1
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end
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elseif input:sub(i, i) == CR then
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if i == 1 then return true end
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i = i - 1
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else
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return false
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end
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if input:sub(i, i) == BACKSLASH and i ~= BackslashAtCommentEnd then
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return isRegex(input, i - 1)
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else
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return true
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end
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end
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local function eatCharacterClass(input, s, e)
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local i = s
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while i <= e do
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if input:find('^[\r\n]', i) then
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return false
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elseif input:sub(i, i + 1) == ':]' then
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local str = input:sub(s, i - 1)
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return CC[str] == 1 and i + 1
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end
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i = i + 1
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end
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return false
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end
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local function eatBrackets(input, i, e)
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if input:sub(i, i) == CARET then i = i + 1 end
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if input:sub(i, i) == RIGHTBRACKET then i = i + 1 end
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while i <= e do
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if input:find('^[\r\n]', i) then
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return false
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elseif input:sub(i, i) == RIGHTBRACKET then
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return i
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elseif input:sub(i, i + 1) == '[:' then
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i = eatCharacterClass(input, i + 2, e)
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if not i then return false end
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elseif input:sub(i, i) == BACKSLASH then
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i = i + 1
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if input:sub(i, i + 1) == CRLF then i = i + 1 end
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end
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i = i + 1
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end
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return false
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end
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local function eatRegex(input, i)
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local e = #input
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while i <= e do
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if input:find('^[\r\n]', i) then
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return false
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elseif input:sub(i, i) == SLASH then
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LastRegexEnd = i
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return i
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elseif input:sub(i, i) == LEFTBRACKET then
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i = eatBrackets(input, i + 1, e)
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if not i then return false end
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elseif input:sub(i, i) == BACKSLASH then
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i = i + 1
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if input:sub(i, i + 1) == CRLF then i = i + 1 end
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end
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i = i + 1
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end
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return false
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end
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local ScanRegexResult
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local function scanGawkRegex(input, index)
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if isRegex(input, index - 2) then
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local i = eatRegex(input, index)
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if not i then
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ScanRegexResult = false
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return false
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end
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local rx = input:sub(index - 1, i)
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for bs in rx:gmatch("[^\\](\\+)[BSsWwy<>`']") do
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-- /\S/ is special, but /\\S/ is not.
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if #bs % 2 == 1 then return i + 1 end
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end
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ScanRegexResult = i + 1
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else
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ScanRegexResult = false
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end
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return false
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end
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-- Is only called immediately after scanGawkRegex().
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local function scanRegex()
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return ScanRegexResult
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end
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local function scanString(input, index)
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local i = index
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local e = #input
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while i <= e do
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if input:find('^[\r\n]', i) then
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return false
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elseif input:sub(i, i) == DQUOTE then
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return i + 1
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elseif input:sub(i, i) == BACKSLASH then
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i = i + 1
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-- lexer.delimited_range() doesn't handle CRLF.
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if input:sub(i, i + 1) == CRLF then i = i + 1 end
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end
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i = i + 1
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end
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return false
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end
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-- purpose: prevent isRegex() from entering a comment line that ends with a
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-- backslash.
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local function scanComment(input, index)
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local _, i = input:find('[^\r\n]*', index)
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if input:sub(i, i) == BACKSLASH then BackslashAtCommentEnd = i end
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return i + 1
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end
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local function scanFieldDelimiters(input, index)
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local i = index
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local e = #input
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local left = input:sub(i - 1, i - 1)
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local count = 1
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local right = DELIMITER_MATCHES[left]
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local left2 = COMPANION[left]
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local count2 = 0
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local right2 = DELIMITER_MATCHES[left2]
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while i <= e do
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if input:find('^[#\r\n]', i) then
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return false
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elseif input:sub(i, i) == right then
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count = count - 1
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if count == 0 then return count2 == 0 and i + 1 end
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elseif input:sub(i, i) == left then
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count = count + 1
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elseif input:sub(i, i) == right2 then
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count2 = count2 - 1
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if count2 < 0 then return false end
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elseif input:sub(i, i) == left2 then
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count2 = count2 + 1
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elseif input:sub(i, i) == DQUOTE then
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i = scanString(input, i + 1)
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if not i then return false end
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i = i - 1
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elseif input:sub(i, i) == SLASH then
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if isRegex(input, i - 1) then
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i = eatRegex(input, i + 1)
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if not i then return false end
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end
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elseif input:sub(i, i) == BACKSLASH then
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if input:sub(i + 1, i + 2) == CRLF then
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i = i + 2
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elseif input:find('^[\r\n]', i + 1) then
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i = i + 1
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end
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end
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i = i + 1
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end
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return false
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end
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-- Whitespace.
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lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
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-- Comments.
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lex:add_rule('comment', token(lexer.COMMENT, '#' * P(scanComment)))
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-- Strings.
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lex:add_rule('string', token(lexer.STRING, DQUOTE * P(scanString)))
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-- No leading sign because it might be binary.
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local float = ((lexer.digit^1 * ('.' * lexer.digit^0)^-1) +
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('.' * lexer.digit^1)) *
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(S('eE') * S('+-')^-1 * lexer.digit^1)^-1
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-- Fields. E.g. $1, $a, $(x), $a(x), $a[x], $"1", $$a, etc.
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lex:add_rule('field',
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token('field', P('$') * S('$+-')^0 *
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(float +
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lexer.word^0 * '(' * P(scanFieldDelimiters) +
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lexer.word^1 * ('[' * P(scanFieldDelimiters))^-1 +
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'"' * P(scanString) +
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'/' * P(eatRegex) * '/')))
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lex:add_style('field', lexer.STYLE_LABEL)
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-- Regular expressions.
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-- Slash delimited regular expressions are preceded by most operators or
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-- the keywords 'print' and 'case', possibly on a preceding line. They
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-- can contain unescaped slashes and brackets in brackets. Some escape
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-- sequences like '\S', '\s' have special meanings with Gawk. Tokens that
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-- contain them are displayed differently.
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lex:add_rule('gawkRegex', token('gawkRegex', SLASH * P(scanGawkRegex)))
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lex:add_style('gawkRegex', lexer.STYLE_PREPROCESSOR..',underlined')
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lex:add_rule('regex', token(lexer.REGEX, SLASH * P(scanRegex)))
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-- Operators.
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lex:add_rule('gawkOperator', token('gawkOperator', P("|&") + "@" + "**=" +
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"**"))
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lex:add_style('gawkOperator', lexer.STYLE_OPERATOR..',underlined')
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lex:add_rule('operator', token(lexer.OPERATOR, S('!%&()*+,-/:;<=>?[\\]^{|}~')))
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-- Numbers.
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lex:add_rule('gawkNumber', token('gawkNumber', lexer.hex_num + lexer.oct_num))
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lex:add_style('gawkNumber', lexer.STYLE_NUMBER..',underlined')
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lex:add_rule('number', token(lexer.NUMBER, float))
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-- Keywords.
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lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
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BEGIN END atan2 break close continue cos delete do else exit exp fflush for
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function getline gsub if in index int length log match next nextfile print
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printf rand return sin split sprintf sqrt srand sub substr system tolower
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toupper while
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]]))
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lex:add_rule('builtInVariable', token('builtInVariable', word_match[[
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ARGC ARGV CONVFMT ENVIRON FILENAME FNR FS NF NR OFMT OFS ORS RLENGTH RS RSTART
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SUBSEP
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]]))
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lex:add_style('builtInVariable', lexer.STYLE_CONSTANT)
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lex:add_rule('gawkBuiltInVariable', token('gawkBuiltInVariable', word_match[[
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ARGIND BINMODE ERRNO FIELDWIDTHS FPAT FUNCTAB IGNORECASE LINT PREC PROCINFO
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ROUNDMODE RT SYMTAB TEXTDOMAIN
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]]))
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lex:add_style('gawkBuiltInVariable', lexer.STYLE_CONSTANT..',underlined')
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-- Functions.
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lex:add_rule('function', token(lexer.FUNCTION, lexer.word * #P('(')))
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-- Identifiers.
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lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
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-- Fold points.
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lex:add_fold_point(lexer.OPERATOR, '{', '}')
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lex:add_fold_point(lexer.COMMENT, '#', lexer.fold_line_comments('#'))
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return lex
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