Class: Peruby::Lexer::State

Inherits:
Object
  • Object
show all
Defined in:
lib/peruby/lexer/state.rb

Overview

Tracks whether the lexer expects a term, operator, statement, block, or reference.

Defined Under Namespace

Classes: Frame

Constant Summary collapse

STATES = 
%i[state term operator block ref].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ State

Returns a new instance of State.



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# File 'lib/peruby/lexer/state.rb', line 13

def initialize
  @expect = :state
  @brackets = []
end

Instance Attribute Details

#brackets ⇒ Object (readonly)

Returns the value of attribute brackets.



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# File 'lib/peruby/lexer/state.rb', line 10

def brackets
  @brackets
end

#expect ⇒ Object

Returns the value of attribute expect.



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# File 'lib/peruby/lexer/state.rb', line 11

def expect
  @expect
end

Instance Method Details

#block! ⇒ Object 



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# File 'lib/peruby/lexer/state.rb', line 41

def block!
  @expect = :block
end

#operator! ⇒ Object 



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# File 'lib/peruby/lexer/state.rb', line 33

def operator!
  @expect = :term
end

#pop(close) ⇒ Object

Raises:



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# File 'lib/peruby/lexer/state.rb', line 22

def pop(close)
  frame = @brackets.pop
  raise CompileError, "Unmatched #{close}" unless frame

  frame
end

#push(open, kind, line) ⇒ Object 



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# File 'lib/peruby/lexer/state.rb', line 18

def push(open, kind, line)
  @brackets << Frame.new(open, kind, line)
end

#statement! ⇒ Object 



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# File 'lib/peruby/lexer/state.rb', line 37

def statement!
  @expect = :state
end

#term! ⇒ Object 



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# File 'lib/peruby/lexer/state.rb', line 29

def term!
  @expect = :operator
end