Julia Kaleidoscope Error

error_test.jl

module ErrorTest
# VectorStream

type VectorStream{T}
  vector  :: Vector{T}
  current :: Integer

  VectorStream(vector) = new(vector, 0)
end

function next!(stream::VectorStream)
  stream.current += 1
  stream.vector[stream.current]
end

function peek!(stream::VectorStream)
  stream.vector[stream.current+1]
end

# Tokens

module Tokens
abstract  Token
immutable Keyword{K} <: Token end
immutable Numeric{T} <: Token value::T end
immutable Identifier <: Token name::Symbol end
end

# AST

module AST
abstract Expression

immutable Numeric{T<:Number} <: Expression
  value::T
end

immutable Variable <: Expression
  name::Symbol
end

immutable Call <: Expression
  func::Symbol
  args::Vector{Expression}
end

end

# Parser

function parse_expr!(tokens)
  println("expr")
  lhs=parse_primary!(tokens)

  println("Should return: $lhs")
  lhs
end


function parse_primary!(tokens)
  println("primary 1")
  parse_primary!(next!(tokens), tokens)
end

function parse_primary!(n::Tokens.Numeric, tokens)
  println("primary 2")
  AST.Numeric(n.value)
end

function parse_primary!(id::Tokens.Identifier, tokens)
  println("primary 4")
  parse_identifier!(id, peek!(tokens), tokens)
end

function parse_identifier!(id, p::Tokens.Keyword{'('}, tokens)
  println("identifier 1")
  next!(tokens)

  call = AST.Call(id.name, AST.Expression[])

  if peek!(tokens) != Tokens.Keyword{')'}()
     parse_args!(tokens, call.args)
  end

  return call
end

function parse_identifier!(id, t, tokens)
  println("identifier 2")
  AST.Variable(id.name)
end

function parse_args!(tokens, args)
  println("args")
  ex = parse_expr!(tokens)
  println("EX: ", ex)
  println("TYPE: ", typeof(ex))
  push!(args, ex)

  continue_args(next!(tokens)) && parse_args!(tokens, args)
end

continue_args(t::Tokens.Keyword{','}) = true
continue_args(t::Tokens.Keyword{')'}) = false


# parse f(1)
const stream = VectorStream{Tokens.Token}([
  Tokens.Identifier(:f),
  Tokens.Keyword{'('}(),
  Tokens.Numeric(1),
  Tokens.Keyword{')'}()
])

println(parse_expr!(stream))


end

messages.jl

# julia 0.3

julia> include("c:/github/kaleidoscope/src/old/error_test.jl")
expr
primary 1
primary 4
identifier 1
args
expr
primary 1
primary 2
Should return: Numeric{Int64}(1)
EX: nothing
TYPE: nothing
ERROR: `convert` has no method matching convert(::Type{Expression}, ::Nothing)
 in push! at array.jl:460
 in parse_args! at c:\github\kaleidoscope\src\old\error_test.jl:98
 in parse_identifier! at c:\github\kaleidoscope\src\old\error_test.jl:82
 in parse_primary! at c:\github\kaleidoscope\src\old\error_test.jl:72
 in parse_expr! at c:\github\kaleidoscope\src\old\error_test.jl:53
 in include at boot.jl:245
 in include_from_node1 at loading.jl:128
while loading c:\github\kaleidoscope\src\old\error_test.jl, in expression starti
ng on line 115

# julia 0.4

julia> include("c:/github/kaleidoscope/src/old/error_test.jl")
WARNING: replacing module ErrorTest
expr
primary 1
primary 4
identifier 1
args
expr
primary 1
primary 2
Should return: ErrorTest.AST.Numeric{Int64}(1)
EX: args
TYPE: args
ERROR: LoadError: MethodError: `convert` has no method matching convert(::Type{ErrorTest.AST.Expression}, ::ASCIIString)
This may have arisen from a call to the constructor ErrorTest.AST.Expression(...),
since type constructors fall back to convert methods.
Closest candidates are:
  call{T}(::Type{T}, ::Any)
  convert{T}(::Type{T}, ::T)
 in push! at array.jl:419
 in parse_args! at c:\github\kaleidoscope\src\old\error_test.jl:98
 in parse_identifier! at c:\github\kaleidoscope\src\old\error_test.jl:82
 in parse_primary! at c:\github\kaleidoscope\src\old\error_test.jl:72
 in parse_expr! at c:\github\kaleidoscope\src\old\error_test.jl:53
 in include at boot.jl:259
 in include_from_node1 at loading.jl:266
while loading c:\github\kaleidoscope\src\old\error_test.jl, in expression starting on line 115