Class: ABI::Type::Parser

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

Overview

nested inside Type - why? why not?

Constant Summary collapse

TUPLE_TYPE_RX = 
/^\((.*)\)
  ((\[[0-9]*\])*)
/x
BASE_TYPE_RX =

Crazy regexp to seperate out base type component (eg. uint), size (eg. 256, 128, nil), array component (eg. [], [45], nil)

/([a-z]*)
 ([0-9]*)
 ((\[[0-9]*\])*)
/x

Class Method Summary collapse

Class Method Details

._parse_array_type(subtype, dims) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 81

def self._parse_array_type( subtype, dims )
   ##
   ## todo/check - double check if the order in reverse
   ##                  in solidity / abi encoding / decoding?
   ##
  dims.each do |dim|
    subtype = if dim == -1
                   Array.new( subtype )
              else
                   FixedArray.new( subtype, dim )
              end
  end

  subtype
end

._parse_base_type(str) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 52

def self._parse_base_type( str )
  _, base, subscript, dimension = BASE_TYPE_RX.match( str ).to_a

    ## note:  use [Integer,Integer] array in the future for sub
    ##          for fixed  (e.g. 128x128 => [128,128]) or such
    ##          for now always assume single integer (as string)
  sub = subscript == '' ? nil : subscript.to_i

  ## e.g. turn "[][1][2]" into [-1,1,2]
  ##         or ""        into  []   -- that is, empty array
  dims = _parse_dims( dimension )

  [base, sub, dims]
end

._parse_dims(str) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 67

def self._parse_dims( str )
  dims = str.scan( /\[[0-9]*\]/ )

  ## note: return -1 for dynamic array size e.g. []
  ##        e.g. "[]"[1...-1]  => ""
  ##             "[0]"[1...-1]  => "0"
  ##             "[1]"[1...-1]  => "1"
  dims = dims.map do |dim|
                       size = dim[1...-1]
                       size == '' ? -1 : size.to_i
                  end
  dims
end

._parse_tuple_type(str) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 121

def self._parse_tuple_type( str )
  ## note: types assumes string WITHOUT enclosing () e.g.
  ##  tuple(string,string,bool)  =>  expected as "string,string,bool"

  depth     = 0
  collected = []
  current   = ''

  ### todo/fix: replace with a simple parser!!!
  ##    allow  () and move verbose tuple() too!!!
  str.each_char do |c|
      case c
      when ',' then
        if depth == 0
          collected << current
          current = ''
        else
          current += c
        end
      when '(' then
        depth += 1
        current += c
      when ')' then
        depth -= 1
        current += c
      else
        current += c
      end
  end
  collected << current unless current.empty?

  collected
end

._validate_base_type(base, sub) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 98

def self._validate_base_type( base, sub )
  case base
  when 'string'
    # note: string can not have any suffix
    raise ParseError, "String cannot have suffix"  if sub
  when 'bytes'
    raise ParseError, "Maximum 32 bytes for fixed-length bytes"  if sub && sub > 32
  when 'uint', 'int'
    raise ParseError, "Integer type must have numerical suffix"  unless sub
    raise ParseError, "Integer size out of bounds"    unless sub >= 8 && sub <= 256
    raise ParseError, "Integer size must be multiple of 8"  unless sub % 8 == 0
  when 'address'
    raise ParseError, "Address cannot have suffix"  if sub
  when 'bool'
    raise ParseError, "Bool cannot have suffix"   if sub
  else
    ## puts "  type: >#{type}<"
    raise ParseError, "Unrecognized type base: #{base}"
  end
end

.parse(type) ⇒ Object 



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# File 'lib/abicoder/parser.rb', line 14

def self.parse( type )
      if type =~ TUPLE_TYPE_RX
           types   = _parse_tuple_type( $1 )
           dims    = _parse_dims( $2 )

           parsed_types = types.map{ |t| parse( t ) }

           return _parse_array_type( Tuple.new( parsed_types ), dims )
      end

     base, sub, dims = _parse_base_type( type )

     _validate_base_type( base, sub )

     subtype =  case base
                when 'string'  then   String.new
                when 'bytes'   then   sub ? FixedBytes.new( sub ) : Bytes.new
                when 'uint'    then   Uint.new( sub )
                when 'int'     then   Int.new( sub )
                when 'address' then   Address.new
                when 'bool'    then   Bool.new
                else
                  ## puts "  type: >#{type}<"
                  raise ParseError, "Unrecognized type base: #{base}"
                end

     _parse_array_type( subtype, dims )
end