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# Evaluates a block at parse time. The result from the block must be a parser
# (something which implements #apply). In the first case, the parser will then
# be applied to the input, creating the result.
#
# Dynamic parses are never cached.
#
# Example:
# dynamic { rand < 0.5 ? str('a') : str('b') }
#
class Parslet::Atoms::Dynamic < Parslet::Atoms::Base
attr_reader :block
def initialize(block)
@block = block
end
def cached?
false
end
def try(source, context, consume_all)
result = block.call(source, context)
# Result is a parslet atom.
return result.apply(source, context, consume_all)
end
def to_s_inner(prec)
"dynamic { ... }"
end
end
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