Module: Bob::Compiler::Substitution

Included in:
Walker
Defined in:
lib/bob/compiler/substitution.rb

Constant Summary collapse

SUBSTITUTION_SCANNER = 
/(\\?{{.+?}})/
SUBSTITUTION_PARSER = 
/
  \A
    {{
      [[:blank:]]*
      (?<path> [0-9a-z_]+ (?:\.[0-9a-z_]+)* )
      [[:blank:]]*
      (?:
        \|\|
        [[:blank:]]*
        (?:
          (?: ' (?<fallback> (?:[^'\\{}]|\\.)*) ' ) |
          (?: " (?<fallback> (?:[^"\\{}]|\\.)*) " )
        )
        [[:blank:]]*
      )?
    }}
  \z
/xi

Instance Method Summary collapse

Instance Method Details

#quote_and_substitute(arg, node) ⇒ Object 



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# File 'lib/bob/compiler/substitution.rb', line 25

def quote_and_substitute(arg, node)
  parts = arg.split(SUBSTITUTION_SCANNER).reject(&:empty?)

  if parts.empty?
    %{""}
  else
    parts.map { |str|

      if SUBSTITUTION_SCANNER =~ str
        if str[0] == "\\"
          quote(str[1..-1] || "")
        else
          if (parsed = SUBSTITUTION_PARSER.match(str))
            if parsed[:fallback]
              "env.get(#{quote parsed[:path]}, #{quote unescape parsed[:fallback]})"
            else
              "env.get(#{quote parsed[:path]})"
            end
          else
            warn "Treating invalid substitution as string: #{str.inspect}", node.parent.line
            quote str
          end
        end
      else
        quote str
      end

    }.join(" + ")
  end
end

#unescape(str) ⇒ Object 



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# File 'lib/bob/compiler/substitution.rb', line 56

def unescape(str)
  str.gsub(/\\(.)/, "\\1")
end