-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
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-- Ada LPeg lexer.
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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('ada')
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-- Whitespace.
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lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
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-- Keywords.
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lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
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abort abs accept all and begin body case declare delay do else elsif end entry
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exception exit for generic goto if in is loop mod new not null or others out
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protected raise record rem renames requeue reverse select separate subtype
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task terminate then type until when while xor
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-- Preprocessor.
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package pragma use with
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-- Function.
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function procedure return
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-- Storage class.
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abstract access aliased array at constant delta digits interface limited of
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private range tagged synchronized
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-- Boolean.
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true false
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]]))
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-- Types.
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lex:add_rule('type', token(lexer.TYPE, word_match[[
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boolean character count duration float integer long_float long_integer
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priority short_float short_integer string
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]]))
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-- Identifiers.
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lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
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-- Strings.
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lex:add_rule('string', token(lexer.STRING,
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lexer.delimited_range('"', true, true)))
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-- Comments.
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lex:add_rule('comment', token(lexer.COMMENT, '--' * lexer.nonnewline^0))
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-- Numbers.
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local hex_num = 'O' * S('xX') * (lexer.xdigit + '_')^1
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local integer = lexer.digit^1 * ('_' * lexer.digit^1)^0
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local float = integer^1 * ('.' * integer^0)^-1 * S('eE') * S('+-')^-1 * integer
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lex:add_rule('number', token(lexer.NUMBER, hex_num +
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S('+-')^-1 * (float + integer) *
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S('LlUuFf')^-3))
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-- Operators.
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lex:add_rule('operator', token(lexer.OPERATOR, S(':;=<>&+-*/.()')))
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return lex
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