class Crass::TokenScanner

Like {Scanner}, but for tokens!

Attributes

current[R]
pos[R]
tokens[R]

Public Class Methods

new(tokens) click to toggle source
# File lib/crass/token-scanner.rb, line 9
def initialize(tokens)
  @tokens = tokens.to_a
  reset
end

Public Instance Methods

collect() { || ... } click to toggle source

Executes the given block, collects all tokens that are consumed during its execution, and returns them.

# File lib/crass/token-scanner.rb, line 16
def collect
  start = @pos
  yield
  @tokens[start...@pos] || []
end
consume() click to toggle source

Consumes the next token and returns it, advancing the pointer. Returns `nil` if there is no next token.

# File lib/crass/token-scanner.rb, line 24
def consume
  @current = @tokens[@pos]
  @pos += 1 if @current
  @current
end
peek() click to toggle source

Returns the next token without consuming it, or `nil` if there is no next token.

# File lib/crass/token-scanner.rb, line 32
def peek
  @tokens[@pos]
end
reconsume() click to toggle source

Reconsumes the current token, moving the pointer back one position.

www.w3.org/TR/2013/WD-css-syntax-3-20130919/#reconsume-the-current-input-token

# File lib/crass/token-scanner.rb, line 39
def reconsume
  @pos -= 1 if @pos > 0
end
reset() click to toggle source

Resets the pointer to the first token in the list.

# File lib/crass/token-scanner.rb, line 44
def reset
  @current = nil
  @pos     = 0
end