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|
$:.unshift File.dirname(__FILE__) + "/../lib"
# This example demonstrates how to do deepest error reporting, as invented
# by John Mettraux (issue #64).
require 'parslet'
require 'parslet/convenience'
def prettify(str)
puts " "*3 + " "*4 + "." + " "*4 + "10" + " "*3 + "." + " "*4 + "20"
str.lines.each_with_index do |line, index|
printf "%02d %s\n",
index+1,
line.chomp
end
end
class Parser < Parslet::Parser
# commons
rule(:space) { match('[ \t]').repeat(1) }
rule(:space?) { space.maybe }
rule(:newline) { match('[\r\n]') }
rule(:comment) { str('#') >> match('[^\r\n]').repeat }
rule(:line_separator) {
(space? >> ((comment.maybe >> newline) | str(';')) >> space?).repeat(1)
}
rule(:blank) { line_separator | space }
rule(:blank?) { blank.maybe }
rule(:identifier) { match('[a-zA-Z0-9_]').repeat(1) }
# res_statement
rule(:reference) {
(str('@').repeat(1,2) >> identifier).as(:reference)
}
rule(:res_action_or_link) {
str('.').as(:dot) >> (identifier >> str('?').maybe ).as(:name) >> str('()')
}
rule(:res_actions) {
(
reference
).as(:resources) >>
(
res_action_or_link.as(:res_action)
).repeat(0).as(:res_actions)
}
rule(:res_statement) {
res_actions >>
(str(':') >> identifier.as(:name)).maybe.as(:res_field)
}
# expression
rule(:expression) {
res_statement
}
# body
rule(:body) {
(line_separator >> (block | expression)).repeat(1).as(:body) >>
line_separator
}
# blocks
rule(:begin_block) {
(str('concurrent').as(:type) >> space).maybe.as(:pre) >>
str('begin').as(:begin) >>
body >>
str('end')
}
rule(:define_block) {
str('define').as(:define) >> space >>
identifier.as(:name) >> str('()') >>
body >>
str('end')
}
rule(:block) {
define_block | begin_block
}
# root
rule(:radix) {
line_separator.maybe >> block >> line_separator.maybe
}
root(:radix)
end
ds = [
%{
define f()
@res.name
end
},
%{
define f()
begin
@res.name
end
end
}
]
ds.each do |d|
puts '-' * 80
prettify(d)
parser = Parser.new
begin
parser.parse_with_debug(d,
:reporter => Parslet::ErrorReporter::Deepest.new)
end
end
puts '-' * 80
|
