Method: Ppr::Preprocessor#initialize

Defined in:

lib/ppr/ppr_core.rb

#initialize(params = {}, apply: ".do", applyR: ".doR", define: ".def", defineR: ".defR", assign: ".assign", loadm: ".load", requirem: ".require", ifm: ".if", elsem: ".else", endifm: ".endif", endm: ".end", expand: ":<", separator: /^|[^\w]|$/, glue: "##", escape: "\\") ⇒ Preprocessor

Creates a new preprocessor, where apply, applyR, define, defineR, assign, loadm, requirem, ifm, elsem and endm are the keywords defining the beginings and end of a macro definitions, and where separator is the regular expression used for separating macro references to the remaining of the code, expand is the string representing the expansion operator of the macro, glue is string used for glueing a macro expension to the text, escape is the escape character.

Assigned parameters can be added through param to be used within the macros of the preprocessed text.

# File 'lib/ppr/ppr_core.rb', line 386

def initialize(params = {},
               apply: ".do", applyR: ".doR", 
               define: ".def", defineR: ".defR",
               assign: ".assign",
               loadm: ".load", requirem: ".require",
               ifm: ".if", elsem: ".else", endifm: ".endif",
               endm: ".end",
               expand: ":<",
               separator: /^|[^\w]|$/, glue: "##",
               escape: "\\")
    # Check and Initialize the keywords
    # NOTE: since there are a lot of checks, use a generic but
    # harder to read code.
    keys = [ "apply", "applyR", "define", "defineR", "assign",
             "loadm", "requirem", "ifm", "elsem", "endifm", "endm"]
    # Sort the keywords by string content to quickly find erroneously
    # identical ones.
    keys.sort_by! {|key| eval(key) }
    # Check for identical keywords.
    keys.each_with_index do |key,i|
        value = eval(key)
        if i+1 < keys.size then
            # Check if the next keyword has the same string.
            nvalue = eval(keys[i+1])
            if value == nvalue then
                # Two keywords with same string.
                raise "'#{key}:#{value}' and '#{keys[i+1]}:#{nvalue}' keywords must be different."
            end
        end
    end

    # Seperate the begin of macro keywords from the others (they
    # are used differently).
    other_keys = ["elsem", "endifm", "endm"]
    begin_keys = keys - other_keys
    # Assign the begin of macro keywords to the corresponding attributes.
    begin_keys.each do |key|
        eval("@#{key} = #{key}.to_s")
    end
    # Generates the structures used for detecting the keywords.
    # For the begining of macros.
    @macro_keys = (begin_keys - other_keys).map do
        |key| self.instance_variable_get("@#{key}")
    end.sort!.reverse
    # For the other keywords.
    other_keys.each do |key|
        eval('@'+key+' = Regexp.new("^\s*#{Regexp.escape('+key+')}\s*$")')
    end

    # Sets the expand command.
    @expand = expand.to_s
    # Check and set the separator, the glue and the escape.
    @separator = Regexp.new("(?:#{separator}|#{glue})")
    @glue = glue.to_s

    # Initialize the current line number to 0.
    @number = LineNumber.new(0)
    # Initialize the macros.
    @macros = KeywordSearcher.new(@separator)

    # Initialize the stack for handling the if macros.
    @if_mode = []

    # Create the execution context for the macros.
    @generator = SaferGenerator.new
    @context = Object.new
    # Process the preprocessing parameters.
    params.each do |k,v|
        parameter_set(k,v)
    end
end