Class: Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/magister_cli/parser.rb

Constant Summary collapse

@@actions = 
[
    ['login', ['username', 'password', 'school']],
    ['auth', ['token', 'school']],
    ['quit', []],
    ['exit', []],
    ['get_classes', ['date_from', 'date_to']]
]

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/magister_cli/parser.rb', line 15

def initialize(string)
    @tokenizer = Tokenizer.new(string)
    @string = string
end

Instance Method Details

#get_args(actionName) ⇒ Object 



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# File 'lib/magister_cli/parser.rb', line 34

def get_args(actionName)
    @@actions.each do |action|
        if action[0] == actionName
            return action[1].dup
        end
    end
end

#is_action?(actionName) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magister_cli/parser.rb', line 20

def is_action?(actionName)
    @@actions.each do |action|
        if action[0] == actionName
            return true
        end
    end
    return false
end

#parse ⇒ Object 



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# File 'lib/magister_cli/parser.rb', line 42

def parse()
    tokens = @tokenizer.tokenize

    i = 0

    ast = Array.new
    while i < tokens.length
        tmp = 0
        props = false
        opts = false
        altOpts = false # true if opts are in the place props would be

        if tokens[0 + i]["type"] != "KEYWORD"
            puts "Current index: #{i.to_s}"
            raise SyntaxError.new "Expected #{tokens[0 + i]["value"]} to be a KEYWORD, is a #{tokens[0 + i]["type"]}"
        end

        if tokens[1 + i] != nil && tokens[1 + i]["type"] == "PARAMS"
            tmp += 1
            props = true
        end

        if tokens[2 + i] != nil && tokens[2 + i]["type"] == "OPTIONS"
            tmp += 1
            opts = true
        end

        if tokens[1 + i] != nil && tokens[1 + i]["type"] == "OPTIONS"
            if opts || props
                raise SyntaxError.new "Cant have type OPTIONS here, must be PARAMS"
            end
            opts = true
            altOpts = true
            tmp += 1
        end

        ast_node = {"action" => tokens[0 + i]["value"]}

        if props
            ast_node["parameters"] = tokens[1 + i]["value"]
        end

        if opts
            if altOpts
                ast_node["options"] = tokens[1 + i]["value"]
            else
                ast_node["options"] = tokens[2 + i]["value"]
            end
        end

        if !is_action? ast_node["action"]
            throw SyntaxError.new "#{ast_node["action"]} is not a valid action!"
        end

        lacking = Array.new
        lacking = get_args(ast_node["action"])

        if props
            ast_node["parameters"].each do |prop|
                if !lacking.include? prop["key"]
                    raise SyntaxError.new "#{prop["key"]} is is already defined or is not a valid parameter for #{ast_node["action"]}!"
                end
                lacking.delete prop["key"]
            end
        else
            ast_node["parameters"] = Array.new
        end

        ast_node["lacking_params"] = lacking

        ast.append(ast_node)

        i += tmp + 1 # + 1 for the keyword itself
    end

    ast
end

#string=(string) ⇒ Object 



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# File 'lib/magister_cli/parser.rb', line 29

def string=(string)
    @string = string
    @tokenizer = Tokenizer.new(string)
end