Class: Puppet::Pops::Parser::Lexer2

Inherits:

Object

Object
Puppet::Pops::Parser::Lexer2

show all

Includes:: EppSupport, HeredocSupport, InterpolationSupport, LexerSupport, SlurpSupport

Defined in:: lib/puppet/pops/parser/lexer2.rb

Constant Summary collapse

TOKEN_LBRACK = ALl tokens have three slots, the token name (a Symbol), the token text (String), and a token text length. All operator and punctuation tokens reuse singleton arrays Tokens that require unique values create a unique array per token. PEFORMANCE NOTES: This construct reduces the amount of object that needs to be created for operators and punctuation. The length is pre-calculated for all singleton tokens. The length is used both to signal the length of the token, and to advance the scanner position (without having to advance it with a scan(regexp)).

[:LBRACK,       '['.freeze,   1].freeze

TOKEN_LISTSTART =

[:LISTSTART,    '['.freeze,   1].freeze

TOKEN_RBRACK =

[:RBRACK,       ']'.freeze,   1].freeze

TOKEN_LBRACE =

[:LBRACE,       '{'.freeze,   1].freeze

TOKEN_RBRACE =

[:RBRACE,       '}'.freeze,   1].freeze

TOKEN_SELBRACE =

[:SELBRACE,     '{'.freeze,   1].freeze

TOKEN_LPAREN =

[:LPAREN,       '('.freeze,   1].freeze

TOKEN_RPAREN =

[:RPAREN,       ')'.freeze,   1].freeze

TOKEN_EQUALS =

[:EQUALS,       '='.freeze,   1].freeze

TOKEN_APPENDS =

[:APPENDS,      '+='.freeze,  2].freeze

TOKEN_DELETES =

[:DELETES,      '-='.freeze,  2].freeze

TOKEN_ISEQUAL =

[:ISEQUAL,      '=='.freeze,  2].freeze

TOKEN_NOTEQUAL =

[:NOTEQUAL,     '!='.freeze,  2].freeze

TOKEN_MATCH =

[:MATCH,        '=~'.freeze,  2].freeze

TOKEN_NOMATCH =

[:NOMATCH,      '!~'.freeze,  2].freeze

TOKEN_GREATEREQUAL =

[:GREATEREQUAL, '>='.freeze,  2].freeze

TOKEN_GREATERTHAN =

[:GREATERTHAN,  '>'.freeze,   1].freeze

TOKEN_LESSEQUAL =

[:LESSEQUAL,    '<='.freeze,  2].freeze

TOKEN_LESSTHAN =

[:LESSTHAN,     '<'.freeze,   1].freeze

TOKEN_FARROW =

[:FARROW,       '=>'.freeze,  2].freeze

TOKEN_PARROW =

[:PARROW,       '+>'.freeze,  2].freeze

TOKEN_LSHIFT =

[:LSHIFT,       '<<'.freeze,  2].freeze

TOKEN_LLCOLLECT =

[:LLCOLLECT,    '<<|'.freeze, 3].freeze

TOKEN_LCOLLECT =

[:LCOLLECT,     '<|'.freeze,  2].freeze

TOKEN_RSHIFT =

[:RSHIFT,       '>>'.freeze,  2].freeze

TOKEN_RRCOLLECT =

[:RRCOLLECT,    '|>>'.freeze, 3].freeze

TOKEN_RCOLLECT =

[:RCOLLECT,     '|>'.freeze,  2].freeze

TOKEN_PLUS =

[:PLUS,         '+'.freeze,   1].freeze

TOKEN_MINUS =

[:MINUS,        '-'.freeze,   1].freeze

TOKEN_DIV =

[:DIV,          '/'.freeze,   1].freeze

TOKEN_TIMES =

[:TIMES,        '*'.freeze,   1].freeze

TOKEN_MODULO =

[:MODULO,       '%'.freeze,   1].freeze

TOKEN_NOT =

[:NOT,          '!'.freeze,   1].freeze

TOKEN_DOT =

[:DOT,          '.'.freeze,   1].freeze

TOKEN_PIPE =

[:PIPE,         '|'.freeze,   1].freeze

TOKEN_AT =

[:AT ,          '@'.freeze,   1].freeze

TOKEN_ATAT =

[:ATAT ,        '@@'.freeze,  2].freeze

TOKEN_COLON =

[:COLON,        ':'.freeze,   1].freeze

TOKEN_COMMA =

[:COMMA,        ','.freeze,   1].freeze

TOKEN_SEMIC =

[:SEMIC,        ';'.freeze,   1].freeze

TOKEN_QMARK =

[:QMARK,        '?'.freeze,   1].freeze

TOKEN_TILDE = lexed but not an operator in Puppet

[:TILDE,        '~'.freeze,   1].freeze

TOKEN_REGEXP =

[:REGEXP,       nil,   0].freeze

TOKEN_IN_EDGE =

[:IN_EDGE,      '->'.freeze,  2].freeze

TOKEN_IN_EDGE_SUB =

[:IN_EDGE_SUB,  '~>'.freeze,  2].freeze

TOKEN_OUT_EDGE =

[:OUT_EDGE,     '<-'.freeze,  2].freeze

TOKEN_OUT_EDGE_SUB =

[:OUT_EDGE_SUB, '<~'.freeze,  2].freeze

TOKEN_STRING = Tokens that are always unique to what has been lexed

[:STRING, nil,          0].freeze

TOKEN_WORD =

[:WORD, nil,            0].freeze

TOKEN_DQPRE =

[:DQPRE,  nil,          0].freeze

TOKEN_DQMID =

[:DQPRE,  nil,          0].freeze

TOKEN_DQPOS =

[:DQPRE,  nil,          0].freeze

TOKEN_NUMBER =

[:NUMBER, nil,          0].freeze

TOKEN_VARIABLE =

[:VARIABLE, nil,        1].freeze

TOKEN_VARIABLE_EMPTY =

[:VARIABLE, ''.freeze,  1].freeze

TOKEN_HEREDOC = HEREDOC has syntax as an argument.

[:HEREDOC, nil, 0].freeze

TOKEN_EPPSTART = EPP_START is currently a marker token, may later get syntax

[:EPP_START, nil, 0].freeze

TOKEN_EPPEND =

[:EPP_END, '%>', 2].freeze

TOKEN_EPPEND_TRIM =

[:EPP_END_TRIM, '-%>', 3].freeze

TOKEN_OTHER = This is used for unrecognized tokens, will always be a single character. This particular instance is not used, but is kept here for documentation purposes.

[:OTHER,  nil,  0]

KEYWORDS = Keywords are all singleton tokens with pre calculated lengths. Booleans are pre-calculated (rather than evaluating the strings “false” “true” repeatedly.

{
  "case"     => [:CASE,     'case',     4],
  "class"    => [:CLASS,    'class',    5],
  "default"  => [:DEFAULT,  'default',  7],
  "define"   => [:DEFINE,   'define',   6],
  "if"       => [:IF,       'if',       2],
  "elsif"    => [:ELSIF,    'elsif',    5],
  "else"     => [:ELSE,     'else',     4],
  "inherits" => [:INHERITS, 'inherits', 8],
  "node"     => [:NODE,     'node',     4],
  "and"      => [:AND,      'and',      3],
  "or"       => [:OR,       'or',       2],
  "undef"    => [:UNDEF,    'undef',    5],
  "false"    => [:BOOLEAN,  false,      5],
  "true"     => [:BOOLEAN,  true,       4],
  "in"       => [:IN,       'in',       2],
  "unless"   => [:UNLESS,   'unless',   6],
  "function" => [:FUNCTION, 'function', 8],
  "type"     => [:TYPE,     'type',     4],
  "attr"     => [:ATTR,     'attr',     4],
  "private"  => [:PRIVATE,  'private',  7],
}

KEYWORD_NAMES = Reverse lookup of keyword name to string

{}

PATTERN_WS =

%r{[[:blank:]\r]+}

PATTERN_COMMENT = The single line comment includes the line ending.

%r{#.*\r?}

PATTERN_MLCOMMENT =

%r{/\*(.*?)\*/}m

PATTERN_REGEX =

%r{/[^/\n]*/}

PATTERN_REGEX_END =

%r{/}

PATTERN_REGEX_A = for replacement to “”

%r{\A/}

PATTERN_REGEX_Z = for replacement to “”

%r{/\Z}

PATTERN_REGEX_ESC = for replacement to “/”

%r{\\/}

PATTERN_CLASSREF = The NAME and CLASSREF in 4x are strict. Each segment must start with a letter a-z and may not contain dashes (w includes letters, digits and _).

%r{((::){0,1}[A-Z][\w]*)+}

PATTERN_NAME =

%r{((::)?[a-z][\w]*)(::[a-z][\w]*)*}

PATTERN_BARE_WORD =

%r{[a-z_](?:[\w-]*[\w])?}

PATTERN_DOLLAR_VAR =

%r{\$(::)?(\w+::)*\w+}

PATTERN_NUMBER =

%r{\b(?:0[xX][0-9A-Fa-f]+|0?\d+(?:\.\d+)?(?:[eE]-?\d+)?)\b}

STRING_BSLASH_BSLASH = PERFORMANCE NOTE: Comparison against a frozen string is faster (than unfrozen).

'\\'.freeze

Instance Attribute Summary collapse

#locator ⇒ Object readonly

Instance Method Summary collapse

#clear ⇒ Object

Clears the lexer state (it is not required to call this as it will be garbage collected and the next lex call (lex_string, lex_file) will reset the internal state..
#emit(token, byte_offset) ⇒ Object

Emits (produces) a token [:tokensymbol, TokenValue] and moves the scanner’s position past the token.
#emit_completed(token, byte_offset) ⇒ Object

Emits the completed token on the form [:tokensymbol, TokenValue. This method does not alter the scanner’s position..
#enqueue(emitted_token) ⇒ Object

Allows subprocessors for heredoc etc to enqueue tokens that are tokenized by a different lexer instance.
#enqueue_completed(token, byte_offset) ⇒ Object

Enqueues a completed token at the given offset.
#file ⇒ Object

TODO: This method should not be used, callers should get the locator since it is most likely required to compute line, position etc given offsets.
#file=(file) ⇒ Object

Convenience method, and for compatibility with older lexer.
#fullscan ⇒ Object

Scans all of the content and returns it in an array Note that the terminating [false, false] token is included in the result.
#initialize ⇒ Lexer2 constructor

A new instance of Lexer2.
#initvars ⇒ Object
#lex_file(file) ⇒ Object

Initializes lexing of the content of the given file.
#lex_string(string, path = '') ⇒ Object
#lex_token ⇒ Object

This lexes one token at the current position of the scanner.
#lex_unquoted_string(string, locator, escapes, interpolate) ⇒ Object

Lexes an unquoted string.
#regexp_acceptable? ⇒ Boolean

Answers after which tokens it is acceptable to lex a regular expression.
#scan {|[false, false]| ... } ⇒ Object

A block must be passed to scan.
#string=(string) ⇒ Object

Convenience method, and for compatibility with older lexer.

Methods included from EppSupport

#fullscan_epp, #interpolate_epp, #scan_epp

Methods included from SlurpSupport

#slurp, #slurp_dqstring, #slurp_sqstring, #slurp_uqstring

Methods included from InterpolationSupport

#enqueue_until, #interpolate_dq, #interpolate_tail_dq, #interpolate_tail_uq, #interpolate_uq, #interpolate_uq_to, #transform_to_variable

Methods included from HeredocSupport

#heredoc, #heredoc_text

Methods included from LexerSupport

#assert_numeric, #followed_by, #format_quote, #lex_error, #lex_error_without_pos, #positioned_message

Constructor Details

#initialize ⇒ `Lexer2`

Returns a new instance of Lexer2.



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# File 'lib/puppet/pops/parser/lexer2.rb', line 177

def initialize()
end

Instance Attribute Details

#locator ⇒ `Object` (readonly)



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# File 'lib/puppet/pops/parser/lexer2.rb', line 175

def locator
  @locator
end

Instance Method Details

#clear ⇒ `Object`

Clears the lexer state (it is not required to call this as it will be garbage collected and the next lex call (lex_string, lex_file) will reset the internal state.

# File 'lib/puppet/pops/parser/lexer2.rb', line 183

def clear()
  # not really needed, but if someone wants to ensure garbage is collected as early as possible
  @scanner = nil
  @locator = nil
  @lexing_context = nil
end

#emit(token, byte_offset) ⇒ `Object`

Emits (produces) a token [:tokensymbol, TokenValue] and moves the scanner’s position past the token

# File 'lib/puppet/pops/parser/lexer2.rb', line 646

def emit(token, byte_offset)
  @scanner.pos = byte_offset + token[2]
  [token[0], TokenValue.new(token, byte_offset, @locator)]
end

#emit_completed(token, byte_offset) ⇒ `Object`

Emits the completed token on the form [:tokensymbol, TokenValue. This method does not alter the scanner’s position.



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# File 'lib/puppet/pops/parser/lexer2.rb', line 654

def emit_completed(token, byte_offset)
  [token[0], TokenValue.new(token, byte_offset, @locator)]
end

#enqueue(emitted_token) ⇒ `Object`

Allows subprocessors for heredoc etc to enqueue tokens that are tokenized by a different lexer instance



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# File 'lib/puppet/pops/parser/lexer2.rb', line 665

def enqueue(emitted_token)
  @token_queue << emitted_token
end

#enqueue_completed(token, byte_offset) ⇒ `Object`

Enqueues a completed token at the given offset



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# File 'lib/puppet/pops/parser/lexer2.rb', line 659

def enqueue_completed(token, byte_offset)
  @token_queue << emit_completed(token, byte_offset)
end

#file ⇒ `Object`

TODO: This method should not be used, callers should get the locator since it is most likely required to compute line, position etc given offsets.



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# File 'lib/puppet/pops/parser/lexer2.rb', line 229

def file
  @locator ? @locator.file : nil
end

#file=(file) ⇒ `Object`

Convenience method, and for compatibility with older lexer. Use the lex_file instead. (Bad form to use overloading of assignment operator for something that is not really an assignment).



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# File 'lib/puppet/pops/parser/lexer2.rb', line 222

def file=(file)
  lex_file(file)
end

#fullscan ⇒ `Object`

Scans all of the content and returns it in an array Note that the terminating [false, false] token is included in the result.

# File 'lib/puppet/pops/parser/lexer2.rb', line 254

def fullscan
  result = []
  scan {|token, value| result.push([token, value]) }
  result
end

#initvars ⇒ `Object`

# File 'lib/puppet/pops/parser/lexer2.rb', line 242

def initvars
  @token_queue = []
  # NOTE: additional keys are used; :escapes, :uq_slurp_pattern, :newline_jump, :epp_*
  @lexing_context = {
    :brace_count => 0,
    :after => nil,
  }
end

#lex_file(file) ⇒ `Object`

Initializes lexing of the content of the given file. An empty string is used if the file does not exist.

# File 'lib/puppet/pops/parser/lexer2.rb', line 235

def lex_file(file)
  initvars
  contents = Puppet::FileSystem.exist?(file) ? Puppet::FileSystem.read(file) : ""
  @scanner = StringScanner.new(contents.freeze)
  @locator = Puppet::Pops::Parser::Locator.locator(contents, file)
end

#lex_string(string, path = '') ⇒ `Object`

# File 'lib/puppet/pops/parser/lexer2.rb', line 199

def lex_string(string, path='')
  initvars
  @scanner = StringScanner.new(string)
  @locator = Puppet::Pops::Parser::Locator.locator(string, path)
end

#lex_token ⇒ `Object`

This lexes one token at the current position of the scanner. PERFORMANCE NOTE: Any change to this logic should be performance measured.

# File 'lib/puppet/pops/parser/lexer2.rb', line 296

def lex_token
  # Using three char look ahead (may be faster to do 2 char look ahead since only 2 tokens require a third
  scn = @scanner
  ctx = @lexing_context
  before = @scanner.pos

  # A look ahead of 3 characters is used since the longest operator ambiguity is resolved at that point.
  # PERFORMANCE NOTE: It is faster to peek once and use three separate variables for lookahead 0, 1 and 2.
  #
  la = scn.peek(3)
  return nil if la.empty?

  # Ruby 1.8.7 requires using offset and length (or integers are returned.
  # PERFORMANCE NOTE.
  # It is slightly faster to use these local variables than accessing la[0], la[1] etc. in ruby 1.9.3
  # But not big enough to warrant two completely different implementations.
  #
  la0 = la[0,1]
  la1 = la[1,1]
  la2 = la[2,1]

  # PERFORMANCE NOTE:
  # A case when, where all the cases are literal values is the fastest way to map from data to code.
  # It is much faster than using a hash with lambdas, hash with symbol used to then invoke send etc.
  # This case statement is evaluated for most character positions in puppet source, and great care must
  # be taken to not introduce performance regressions.
  #
  case la0

  when '.'
    emit(TOKEN_DOT, before)

  when ','
    emit(TOKEN_COMMA, before)

  when '['
    if (before == 0 || scn.string[locator.char_offset(before)-1,1] =~ /[[:blank:]\r\n]+/)
      emit(TOKEN_LISTSTART, before)
    else
      emit(TOKEN_LBRACK, before)
    end

  when ']'
    emit(TOKEN_RBRACK, before)

  when '('
    emit(TOKEN_LPAREN, before)

  when ')'
    emit(TOKEN_RPAREN, before)

  when ';'
    emit(TOKEN_SEMIC, before)

  when '?'
    emit(TOKEN_QMARK, before)

  when '*'
    emit(TOKEN_TIMES, before)

  when '%'
    if la1 == '>' && ctx[:epp_mode]
      scn.pos += 2
      if ctx[:epp_mode] == :expr
        enqueue_completed(TOKEN_EPPEND, before)
      end
      ctx[:epp_mode] = :text
      interpolate_epp
    else
      emit(TOKEN_MODULO, before)
    end

  when '{'
    # The lexer needs to help the parser since the technology used cannot deal with
    # lookahead of same token with different precedence. This is solved by making left brace
    # after ? into a separate token.
    #
    ctx[:brace_count] += 1
    emit(if ctx[:after] == :QMARK
      TOKEN_SELBRACE
    else
      TOKEN_LBRACE
    end, before)

  when '}'
    ctx[:brace_count] -= 1
    emit(TOKEN_RBRACE, before)

    # TOKENS @, @@, @(
  when '@'
    case la1
    when '@'
      emit(TOKEN_ATAT, before) # TODO; Check if this is good for the grammar
    when '('
      heredoc
    else
      emit(TOKEN_AT, before)
    end

    # TOKENS |, |>, |>>
  when '|'
    emit(case la1
    when '>'
      la2 == '>' ? TOKEN_RRCOLLECT : TOKEN_RCOLLECT
    else
      TOKEN_PIPE
    end, before)

    # TOKENS =, =>, ==, =~
  when '='
    emit(case la1
    when '='
      TOKEN_ISEQUAL
    when '>'
      TOKEN_FARROW
    when '~'
      TOKEN_MATCH
    else
      TOKEN_EQUALS
    end, before)

    # TOKENS '+', '+=', and '+>'
  when '+'
    emit(case la1
    when '='
      TOKEN_APPENDS
    when '>'
      TOKEN_PARROW
    else
      TOKEN_PLUS
    end, before)

    # TOKENS '-', '->', and epp '-%>' (end of interpolation with trim)
  when '-'
    if ctx[:epp_mode] && la1 == '%' && la2 == '>'
      scn.pos += 3
      if ctx[:epp_mode] == :expr
        enqueue_completed(TOKEN_EPPEND_TRIM, before)
      end
      interpolate_epp(:with_trim)
    else
      emit(case la1
      when '>'
        TOKEN_IN_EDGE
      when '='
        TOKEN_DELETES
      else
        TOKEN_MINUS
      end, before)
    end

    # TOKENS !, !=, !~
  when '!'
    emit(case la1
    when '='
      TOKEN_NOTEQUAL
    when '~'
      TOKEN_NOMATCH
    else
      TOKEN_NOT
    end, before)

    # TOKENS ~>, ~
  when '~'
    emit(la1 == '>' ? TOKEN_IN_EDGE_SUB : TOKEN_TILDE, before)

  when '#'
    scn.skip(PATTERN_COMMENT)
    nil

    # TOKENS '/', '/*' and '/ regexp /'
  when '/'
    case la1
    when '*'
      scn.skip(PATTERN_MLCOMMENT)
      nil

    else
      # regexp position is a regexp, else a div
      if regexp_acceptable? && value = scn.scan(PATTERN_REGEX)
        # Ensure an escaped / was not matched
        while value[-2..-2] == STRING_BSLASH_BSLASH # i.e. \\
          value += scn.scan_until(PATTERN_REGEX_END)
        end
        regex = value.sub(PATTERN_REGEX_A, '').sub(PATTERN_REGEX_Z, '').gsub(PATTERN_REGEX_ESC, '/')
        emit_completed([:REGEX, Regexp.new(regex), scn.pos-before], before)
      else
        emit(TOKEN_DIV, before)
      end
    end

    # TOKENS <, <=, <|, <<|, <<, <-, <~
  when '<'
    emit(case la1
    when '<'
      if la2 == '|'
        TOKEN_LLCOLLECT
      else
        TOKEN_LSHIFT
      end
    when '='
      TOKEN_LESSEQUAL
    when '|'
      TOKEN_LCOLLECT
    when '-'
      TOKEN_OUT_EDGE
    when '~'
      TOKEN_OUT_EDGE_SUB
    else
      TOKEN_LESSTHAN
    end, before)

    # TOKENS >, >=, >>
  when '>'
    emit(case la1
    when '>'
      TOKEN_RSHIFT
    when '='
      TOKEN_GREATEREQUAL
    else
      TOKEN_GREATERTHAN
    end, before)

    # TOKENS :, ::CLASSREF, ::NAME
  when ':'
    if la1 == ':'
      before = scn.pos
      # PERFORMANCE NOTE: This could potentially be speeded up by using a case/when listing all
      # upper case letters. Alternatively, the 'A', and 'Z' comparisons may be faster if they are
      # frozen.
      #
      if la2 >= 'A' && la2 <= 'Z'
        # CLASSREF or error
        value = scn.scan(PATTERN_CLASSREF)
        if value
          after = scn.pos
          emit_completed([:CLASSREF, value.freeze, after-before], before)
        else
          # move to faulty position ('::<uc-letter>' was ok)
          scn.pos = scn.pos + 3
          lex_error("Illegal fully qualified class reference")
        end
      else
        # NAME or error
        value = scn.scan(PATTERN_NAME)
        if value
          emit_completed([:NAME, value.freeze, scn.pos-before], before)
        else
          # move to faulty position ('::' was ok)
          scn.pos = scn.pos + 2
          lex_error("Illegal fully qualified name")
        end
      end
    else
      emit(TOKEN_COLON, before)
    end

  when '$'
    if value = scn.scan(PATTERN_DOLLAR_VAR)
      emit_completed([:VARIABLE, value[1..-1].freeze, scn.pos - before], before)
    else
      # consume the $ and let higher layer complain about the error instead of getting a syntax error
      emit(TOKEN_VARIABLE_EMPTY, before)
    end

  when '"'
    # Recursive string interpolation, 'interpolate' either returns a STRING token, or
    # a DQPRE with the rest of the string's tokens placed in the @token_queue
    interpolate_dq

  when "'"
    emit_completed([:STRING, slurp_sqstring.freeze, scn.pos - before], before)

  when '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
    value = scn.scan(PATTERN_NUMBER)
    if value
      length = scn.pos - before
      assert_numeric(value, length)
      emit_completed([:NUMBER, value.freeze, length], before)
    else
      # move to faulty position ([0-9] was ok)
      scn.pos = scn.pos + 1
      lex_error("Illegal number")
    end

  when 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
  'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '_'
    value = scn.scan(PATTERN_NAME)
    # NAME or false start because followed by hyphen(s), underscore or word
    if value && !scn.match?(/^-+\w/)
      emit_completed(KEYWORDS[value] || [:NAME, value.freeze, scn.pos - before], before)
    else
      # Restart and check entire pattern (for ease of detecting non allowed trailing hyphen)
      scn.pos = before
      value = scn.scan(PATTERN_BARE_WORD)
      # If the WORD continues with :: it must be a correct fully qualified name
      if value && !(fully_qualified = scn.match?(/::/))
        emit_completed([:WORD, value.freeze, scn.pos - before], before)
      else
        # move to faulty position ([a-z_] was ok)
        scn.pos = scn.pos + 1
        if fully_qualified
          lex_error("Illegal fully qualified name")
        else
          lex_error("Illegal name or bare word")
        end
      end
    end

  when 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
  'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
    value = scn.scan(PATTERN_CLASSREF)
    if value
      emit_completed([:CLASSREF, value.freeze, scn.pos - before], before)
    else
      # move to faulty position ([A-Z] was ok)
      scn.pos = scn.pos + 1
      lex_error("Illegal class reference")
    end

  when "\n"
    # If heredoc_cont is in effect there are heredoc text lines to skip over
    # otherwise just skip the newline.
    #
    if ctx[:newline_jump]
      scn.pos = ctx[:newline_jump]
      ctx[:newline_jump] = nil
    else
      scn.pos += 1
    end
    return nil

  when ' ', "\t", "\r"
    scn.skip(PATTERN_WS)
    return nil

  else
    # In case of unicode spaces of various kinds that are captured by a regexp, but not by the
    # simpler case expression above (not worth handling those special cases with better performance).
    if scn.skip(PATTERN_WS)
      nil
    else
      # "unrecognized char"
      emit([:OTHER, la0, 1], before)
    end
  end
end

#lex_unquoted_string(string, locator, escapes, interpolate) ⇒ `Object`

Lexes an unquoted string.

Parameters:

string (String) —

the string to lex
locator (Puppet::Pops::Parser::Locator) —

the locator to use (a default is used if nil is given)
escapes (Array<String>) —

array of character strings representing the escape sequences to transform
interpolate (Boolean) —

whether interpolation of expressions should be made or not.

# File 'lib/puppet/pops/parser/lexer2.rb', line 211

def lex_unquoted_string(string, locator, escapes, interpolate)
  initvars
  @scanner = StringScanner.new(string)
  @locator = locator || Puppet::Pops::Parser::Locator.locator(string, '')
  @lexing_context[:escapes] = escapes || UQ_ESCAPES
  @lexing_context[:uq_slurp_pattern] = (interpolate || !escapes.empty?) ? SLURP_UQ_PATTERN : SLURP_ALL_PATTERN
end

#regexp_acceptable? ⇒ `Boolean`

Answers after which tokens it is acceptable to lex a regular expression. PERFORMANCE NOTE: It may be beneficial to turn this into a hash with default value of true for missing entries. A case expression with literal values will however create a hash internally. Since a reference is always needed to the hash, this access is almost as costly as a method call.

Returns:

(Boolean)

# File 'lib/puppet/pops/parser/lexer2.rb', line 675

def regexp_acceptable?
  case @lexing_context[:after]

  # Ends of (potential) R-value generating expressions
  when :RPAREN, :RBRACK, :RRCOLLECT, :RCOLLECT
    false

  # End of (potential) R-value - but must be allowed because of case expressions
  # Called out here to not be mistaken for a bug.
  when :RBRACE
    true

  # Operands (that can be followed by DIV (even if illegal in grammar)
  when :NAME, :CLASSREF, :NUMBER, :STRING, :BOOLEAN, :DQPRE, :DQMID, :DQPOST, :HEREDOC, :REGEX
    false

  else
    true
  end
end

#scan {|[false, false]| ... } ⇒ `Object`

A block must be passed to scan. It will be called with two arguments, a symbol for the token, and an instance of LexerSupport::TokenValue PERFORMANCE NOTE: The TokenValue is designed to reduce the amount of garbage / temporary data and to only convert the lexer’s internal tokens on demand. It is slightly more costly to create an instance of a class defined in Ruby than an Array or Hash, but the gain is much bigger since transformation logic is avoided for many of its members (most are never used (e.g. line/pos information which is only of value in general for error messages, and for some expressions (which the lexer does not know about).

Yields:

([false, false])

# File 'lib/puppet/pops/parser/lexer2.rb', line 268

def scan
  # PERFORMANCE note: it is faster to access local variables than instance variables.
  # This makes a small but notable difference since instance member access is avoided for
  # every token in the lexed content.
  #
  scn   = @scanner
  ctx   = @lexing_context
  queue = @token_queue

  lex_error_without_pos("Internal Error: No string or file given to lexer to process.") unless scn

  scn.skip(PATTERN_WS)

  # This is the lexer's main loop
  until queue.empty? && scn.eos? do
    if token = queue.shift || lex_token
      ctx[:after] = token[0]
      yield token
    end
  end

  # Signals end of input
  yield [false, false]
end

#string=(string) ⇒ `Object`

Convenience method, and for compatibility with older lexer. Use the lex_string instead which allows passing the path to use without first having to call file= (which reads the file if it exists). (Bad form to use overloading of assignment operator for something that is not really an assignment. Also, overloading of = does not allow passing more than one argument).



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# File 'lib/puppet/pops/parser/lexer2.rb', line 195

def string=(string)
  lex_string(string, '')
end

Class: Puppet::Pops::Parser::Lexer2

Constant Summary collapse

Constants included from EppSupport

Constants included from SlurpSupport

Constants included from InterpolationSupport

Constants included from HeredocSupport

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from EppSupport

Methods included from SlurpSupport

Methods included from InterpolationSupport

Methods included from HeredocSupport

Methods included from LexerSupport

Constructor Details

#initialize ⇒ Lexer2

Instance Attribute Details

#locator ⇒ Object (readonly)

Instance Method Details

#clear ⇒ Object

#emit(token, byte_offset) ⇒ Object

#emit_completed(token, byte_offset) ⇒ Object

#enqueue(emitted_token) ⇒ Object

#enqueue_completed(token, byte_offset) ⇒ Object

#file ⇒ Object

#file=(file) ⇒ Object

#fullscan ⇒ Object

#initvars ⇒ Object

#lex_file(file) ⇒ Object

#lex_string(string, path = '') ⇒ Object

#lex_token ⇒ Object

#lex_unquoted_string(string, locator, escapes, interpolate) ⇒ Object

#regexp_acceptable? ⇒ Boolean

#scan {|[false, false]| ... } ⇒ Object

#string=(string) ⇒ Object