sbt-parboiled2-boost is a SBT plugin that works with entire AST of extended parboiled2-like grammar. It parses all rules of particular grammar, performs deep optimizations for all rules, and produces parboiled2 Scala parsers.

Extended parobiled2 grammar for ABC-parser is as follows:

InputLine ::= &(A ~ "c") ~ oneOrMore("a") ~ B ~ !("a" | "b" | "c") ~ EOI
A: Rule0  ::= "a" ~ optional(A) ~ "b"
B: Rule0  ::= "b" ~ optional(B) ~ "c"

Source code should be placed in $(sourceDirectory in Compile)/parboiled folder.

During compilation the plugin parses these sources, performs optimizations and places output code to $(sourceDirectory in Compile)/scala folder:

import org.parboiled2._

class ABCParser(val input: ParserInput) extends Parser {
  def InputLine = rule { &(A ~ "c") ~ oneOrMore("a") ~ B ~ !("a" | "b" | "c") ~ EOI }

  def A: Rule0 = rule { "a" ~ optional(A) ~ "b" }

  def B: Rule0 = rule { "b" ~ optional(B) ~ "c" }
}

Simple rules calls inlined as is.

"a" ~ "b" ~ "c" rule is squashed to "abc".

Meta-rules without overhead.

https://groups.google.com/forum/#!msg/parboiled-user/kgS30ZQqDYM/0hdXe3AaUy0J

https://github.com/alexander-myltsev/sbt-parboiled2-boost-samples

Originally based on sbt-boilerplate