diff --git a/lib/philomena/search/lexer.ex b/lib/philomena/search/lexer.ex
index 56d7bde8..24407a64 100644
--- a/lib/philomena/search/lexer.ex
+++ b/lib/philomena/search/lexer.ex
@@ -1,6 +1,11 @@
 defmodule Philomena.Search.Lexer do
   def lex(input) do
-    accept(input |> to_charlist, :outer)
+    {:ok, accept(input |> to_charlist, :outer)}
+  rescue
+    e in ArgumentError ->
+      {:error, e.message}
+    _ ->
+      {:error, "Parsing error."}
   end
 
   #
@@ -33,8 +38,8 @@ defmodule Philomena.Search.Lexer do
   # Quoted term state
   #
 
-  defp accept([?\\, c] ++ rest, term, :quoted_term), do: accept(rest, term <> <<c::utf8>>, :quoted_term)
-  defp accept([?\\], _term, :quoted_term), do: raise ArgumentError, "Unpaired backslash."
+  defp accept('\\"' ++ rest, term, :quoted_term), do: accept(rest, term <> "\"", :quoted_term)
+  defp accept('\\', _term, :quoted_term), do: raise ArgumentError, "Unpaired backslash."
   defp accept('"' ++ rest, term, :quoted_term), do: [{:term, term} | accept(rest, :outer)]
   defp accept([c] ++ rest, term, :quoted_term), do: accept(rest, term <> <<c::utf8>>, :quoted_term)
   defp accept([], _term, :quoted_term), do: raise ArgumentError, "Imbalanced quotes."
@@ -43,22 +48,22 @@ defmodule Philomena.Search.Lexer do
   # Term state
   #
 
-  defp accept([?\\, c] ++ rest, term, depth, :term), do: accept(rest, term <> <<c::utf8>>, depth, :term)
+  defp accept([?\\, c] ++ rest, term, depth, :term) when c in '()\\', do: accept(rest, term <> <<c::utf8>>, depth, :term)
   defp accept('\\', _term, _depth, :term), do: raise ArgumentError, "Unpaired backslash."
   defp accept('(' ++ rest, term, depth, :term), do: accept(rest, term <> "(", depth + 1, :term)
-  defp accept(')' ++ rest, term, 0, :term), do: [{:term, term}, {:rparen, ")"} | accept(rest, :outer)]
+  defp accept(')' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:rparen, ")"} | accept(rest, :outer)]
   defp accept(')' ++ rest, term, depth, :term), do: accept(rest, term <> ")", depth - 1, :term)
-  defp accept(' AND' ++ rest, term, 0, :term), do: [{:term, term}, {:and, "AND"} | accept(rest, :outer)]
-  defp accept(' OR' ++ rest, term, 0, :term), do: [{:term, term}, {:or, "OR"} | accept(rest, :outer)]
-  defp accept(' &&' ++ rest, term, 0, :term), do: [{:term, term}, {:and, "&&"} | accept(rest, :outer)]
-  defp accept(' ||' ++ rest, term, 0, :term), do: [{:term, term}, {:or, "||"} | accept(rest, :outer)]
-  defp accept(',' ++ rest, term, 0, :term), do: [{:term, term}, {:and, ","} | accept(rest, :outer)]
+  defp accept(' AND' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:and, "AND"} | accept(rest, :outer)]
+  defp accept(' OR' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:or, "OR"} | accept(rest, :outer)]
+  defp accept(' &&' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:and, "&&"} | accept(rest, :outer)]
+  defp accept(' ||' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:or, "||"} | accept(rest, :outer)]
+  defp accept(',' ++ rest, term, 0, :term), do: [{:term, String.trim(term)}, {:and, ","} | accept(rest, :outer)]
   defp accept([?^, c] ++ rest, term, 0, :term) when c in '+-0123456789', do: [{:term, term}, {:boost, "^"} | accept([c | rest], :float)]
   defp accept([?~, c] ++ rest, term, 0, :term) when c in '+-0123456789', do: [{:term, term}, {:fuzz, "~"} | accept([c | rest], :float)]
   defp accept('^' ++ rest, term, depth, :term), do: accept(rest, term <> "^", depth, :term)
   defp accept('~' ++ rest, term, depth, :term), do: accept(rest, term <> "~", depth, :term)
   defp accept([c] ++ rest, term, depth, :term), do: accept(rest, term <> <<c::utf8>>, depth, :term)
-  defp accept([], term, 0, :term), do: [term: term, eof: "$"]
+  defp accept([], term, 0, :term), do: [term: String.trim(term), eof: "$"]
   defp accept([], _term, _depth, :term), do: raise ArgumentError, "Imbalanced parentheses."
 
   #
@@ -79,6 +84,7 @@ defmodule Philomena.Search.Lexer do
   defp accept(',' ++ rest, term, :float_w), do: [{:float, to_number(term)}, {:and, ","} | accept(rest, :outer)]
   defp accept('^' ++ rest, term, :float_w), do: [{:float, to_number(term)}, {:boost, "^"} | accept(rest, :float)]
   defp accept('~' ++ rest, term, :float_w), do: [{:float, to_number(term)}, {:fuzz, "~"} | accept(rest, :float)]
+  defp accept(' ' ++ rest, term, :float_w), do: [{:float, to_number(term)} | accept(rest, :outer)]
   defp accept([], term, :float_w), do: [float: to_number(term), eof: "$"]
   defp accept(_input, _term, :float_w), do: raise ArgumentError, "Expected a number."
 
@@ -91,6 +97,7 @@ defmodule Philomena.Search.Lexer do
   defp accept(',' ++ rest, term, :float_f), do: [{:float, to_number(term)}, {:and, ","} | accept(rest, :outer)]
   defp accept('^' ++ rest, term, :float_f), do: [{:float, to_number(term)}, {:boost, "^"} | accept(rest, :float)]
   defp accept('~' ++ rest, term, :float_f), do: [{:float, to_number(term)}, {:fuzz, "~"} | accept(rest, :float)]
+  defp accept(' ' ++ rest, term, :float_f), do: [{:float, to_number(term)} | accept(rest, :outer)]
   defp accept([], term, :float_f), do: [float: to_number(term), eof: "$"]
   defp accept(_input, _term, :float_f), do: raise ArgumentError, "Expected a number."
 
diff --git a/lib/philomena/search/lexer_two.ex b/lib/philomena/search/lexer_two.ex
new file mode 100644
index 00000000..2041f999
--- /dev/null
+++ b/lib/philomena/search/lexer_two.ex
@@ -0,0 +1,103 @@
+defmodule Philomena.Search.LexerTwo do
+  import NimbleParsec
+
+  defp to_number(term) do
+    {float_val, _} = :string.to_float(term)
+    {int_val, _} = :string.to_integer(term)
+
+    cond do
+      is_float(float_val) ->
+        float_val
+      is_integer(int_val) ->
+        int_val
+    end
+  end
+
+  l_and =
+    choice([string("AND"), string("&&"), string(",")])
+    |> unwrap_and_tag(:and)
+
+  l_or =
+    choice([string("OR"), string("||")])
+    |> unwrap_and_tag(:or)
+
+  l_not =
+    choice([string("NOT"), string("!"), string("-")])
+    |> unwrap_and_tag(:not)
+
+  lparen = string("(") |> unwrap_and_tag(:lparen)
+  rparen = string(")") |> unwrap_and_tag(:rparen)
+
+  number =
+    optional(ascii_char('-+'))
+    |> ascii_char([?0..?9])
+    |> times(min: 1)
+    |> optional(ascii_char('.') |> ascii_char([?0..?9]) |> times(min: 1))
+    |> reduce(:to_number)
+
+  boost = ignore(string("^")) |> unwrap_and_tag(number, :boost)
+  fuzz = ignore(string("~")) |> unwrap_and_tag(number, :fuzz)
+
+  space =
+    choice([string(" "), string("\t"), string("\n"), string("\r"), string("\v"), string("\f")])
+    |> ignore()
+
+  quot = string("\"")
+
+  quoted_term = 
+    ignore(quot)
+    |> choice([
+      ignore(string("\\")) |> string("\""),
+      ignore(string("\\")) |> string("\\"),
+      string("\\") |> utf8_char([]),
+      utf8_char(not: ?")
+    ])
+    |> times(min: 1)
+    |> ignore(quot)
+    |> reduce({List, :to_string, []})
+    |> unwrap_and_tag(:term)
+
+  stop_words = choice([
+    string("\\") |> eos(),
+    string(","),
+    concat(space, l_and),
+    concat(space, l_or),
+    concat(space, l_not),
+    rparen,
+    fuzz,
+    boost
+  ])
+
+  defcombinatorp :simple_term,
+    lookahead_not(stop_words)
+    |> choice([
+      string("\\") |> utf8_char([]),
+      string("(") |> parsec(:simple_term) |> string(")"),
+      utf8_char([]),
+    ])
+    |> times(min: 1)
+
+  unquoted_term =
+    parsec(:simple_term)
+    |> reduce({List, :to_string, []})
+    |> unwrap_and_tag(:term)
+
+  outer = choice([
+    l_and,
+    l_or,
+    l_not,
+    lparen,
+    rparen,
+    boost,
+    fuzz,
+    space,
+    quoted_term,
+    unquoted_term
+  ])
+
+  search =
+    times(outer, min: 1)
+    |> eos()
+
+  defparsec :search, search
+end
\ No newline at end of file
diff --git a/lib/philomena/search/parser.ex b/lib/philomena/search/parser.ex
new file mode 100644
index 00000000..9fa3d66f
--- /dev/null
+++ b/lib/philomena/search/parser.ex
@@ -0,0 +1,97 @@
+defmodule Philomena.Search.Parser do
+  alias Philomena.Search.Lexer
+
+  def parse(ctx, tokens) do
+    {tree, [eof: "$"]} = search_top(ctx, tokens)
+
+    {:ok, tree}
+  rescue
+    e in ArgumentError ->
+      {:error, e.message}
+    _ ->
+      {:error, "Parsing error."}
+  end
+
+  #
+  # Predictive LL(k) parser for search grammar
+  #
+  defp search_top(ctx, tokens), do: search_or(ctx, tokens)
+
+  #
+  # Boolean OR
+  #
+  defp search_or(ctx, tokens) do
+    case search_and(ctx, tokens) do
+      {left, [{:or, _} | r_tokens]} ->
+        {right, rest} = search_top(ctx, r_tokens)
+        {%{bool: %{should: [left, right]}}, rest}
+      {child, rest} ->
+        {child, rest}
+    end
+  end
+
+  #
+  # Boolean AND
+  #
+  defp search_and(ctx, tokens) do
+    case search_boost(ctx, tokens) do
+      {left, [{:and, _} | r_tokens]} ->
+        {right, rest} = search_top(ctx, r_tokens)
+        {%{bool: %{must: [left, right]}}, rest}
+      {child, rest} ->
+        {child, rest}
+    end
+  end
+
+  #
+  # Subquery score boosting
+  #
+  defp search_boost(ctx, tokens) do
+    case search_not(ctx, tokens) do
+      {child, [{:boost, _}, {:float, value} | r_tokens]} ->
+        {%{function_score: %{query: child, boost_factor: value}}, r_tokens}
+      {child, rest} ->
+        {child, rest}
+    end
+  end
+
+  #
+  # Boolean NOT
+  #
+  defp search_not(ctx, [{:not, _} | r_tokens]) do
+    {child, rest} = search_top(ctx, r_tokens)
+
+    {%{bool: %{must_not: child}}, rest}
+  end
+  defp search_not(ctx, tokens), do: search_group(ctx, tokens)
+
+  #
+  # Logical grouping
+  #
+  defp search_group(ctx, [{:lparen, _} | rest]) do
+    case search_top(ctx, rest) do
+      {child, [{:rparen, _} | r_tokens]} ->
+        {child, r_tokens}
+      _ ->
+        raise ArgumentError, "Imbalanced parentheses."
+    end
+  end
+  defp search_group(_ctx, [{:rparen, _} | _rest]), do: raise ArgumentError, "Imbalanced parentheses."
+  defp search_group(ctx, tokens), do: search_fuzz(ctx, tokens)
+
+  #
+  # Term fuzzing
+  #
+  defp search_fuzz(ctx, tokens) do
+    nil
+  end
+
+  #
+  # Search terms
+  #
+  defp search_term(ctx, [{:term, t} | rest]) do
+    {TermParser.parse(ctx, t), rest}
+  end
+  defp search_term(_ctx, [eof: "$"]), do: raise ArgumentError, "Expected a term, got <end of input>."
+  defp search_term(_ctx, [{_, text} | _rest]), do: raise ArgumentError, "Expected a term, got `#{text}'."
+end
\ No newline at end of file
diff --git a/lib/philomena/search/term_lexer.ex b/lib/philomena/search/term_lexer.ex
new file mode 100644
index 00000000..f27532ae
--- /dev/null
+++ b/lib/philomena/search/term_lexer.ex
@@ -0,0 +1,247 @@
+"""
+defmodule Philomena.Search.TermLexer do
+  def lex(opts, input) do
+    {:ok | accept(opts, input, :literal)}
+  #rescue
+  #  e in ArgumentError ->
+  #    {:error, e.message}
+  #  _ ->
+  #    {:error, "Parsing error."}
+  end
+
+  #
+  # Literal fields
+  #
+
+  defp accept([field | r_fields], opts, input, :literal_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:literal_field, field} | accept(rest, :literal)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:literal_field, field} | accept(rest, :literal)]
+      _ ->
+        accept(r_fields, opts, input, :literal_field)
+    end
+  end
+  defp accept([], %{boolean_fields: fields} = opts, input, :literal_field), do: accept(fields, opts, input, :boolean_field)
+
+  #
+  # Boolean fields
+  #
+
+  defp accept([field | r_fields], opts, input, :boolean_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:boolean_field, field} | accept(rest, :boolean)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:boolean_field, field} | accept(rest, :boolean)]
+      _ ->
+        accept(r_fields, opts, input, :boolean_field)
+    end
+  end
+  defp accept([], %{ngram_fields: fields} = opts, input, :boolean_field), do: accept(fields, opts, input, :ngram_field)
+
+  #
+  # NLP-analyzed fields
+  #
+
+  defp accept([field | r_fields], opts, input, :ngram_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:ngram_field, field} | accept(rest, :literal)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:ngram_field, field} | accept(rest, :literal)]
+      _ ->
+        accept(r_fields, opts, input, :ngram_field)
+    end
+  end
+  defp accept([], %{ip_fields: fields} = opts, input, :ngram_field), do: accept(fields, opts, input, :ip_fieldngram
+
+  #
+  # IP address and CIDR range fields
+  #
+
+  defp accept([field | r_fields], opts, input, :ip_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:ip_field, field} | accept(rest, :ip)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:ip_field, field} | accept(rest, :ip)]
+      _ ->
+        accept(r_fields, opts, input, :ip_field)
+    end
+  end
+  defp accept([], %{int_fields: fields} = opts, input, :ip_field), do: accept(fields, opts, input, :int_field)
+
+  #
+  # Integer fields
+  #
+
+  defp accept([field | r_fields], opts, input, :int_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:int_field, field}, {:range, :eq} | accept(rest, :int)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:int_field, field}, {:range, :eq} | accept(rest, :int)]
+      <<^field::binary-size(sz), ".lt:", rest::binary>> ->
+        [{:int_field, field}, {:range, :lt} | accept(rest, :int)]
+      <<^field::binary-size(sz), ".lte:", rest::binary>> ->
+        [{:int_field, field}, {:range, :lte}. accept(rest, :int)]
+      <<^field::binary-size(sz), ".gt:", rest::binary>> ->
+        [{:int_field, field}, {:range, :gt} | accept(rest, :int)]
+      <<^field::binary-size(sz), ".gte:", rest::binary>> ->
+        [{:int_field, field}, {:range, :gte} | accept(rest, :int)]
+      _ ->
+        accept(r_fields, opts, input, :int_field)
+    end
+  end
+  defp accept([], %{float_fields: fields} = opts, input, :int_field), do: accept(fields, opts, input, :float_field)
+
+  #
+  # Float fields
+  #
+
+  defp accept([field | r_fields], opts, input, :float_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:float_field, field}, {:range, :eq} | accept(rest, :float)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:float_field, field}, {:range, :eq} | accept(rest, :float)]
+      <<^field::binary-size(sz), ".lt:", rest::binary>> ->
+        [{:float_field, field}, {:range, :lt} | accept(rest, :float)]
+      <<^field::binary-size(sz), ".lte:", rest::binary>> ->
+        [{:float_field, field}, {:range, :lte} | accept(rest, :float)]
+      <<^field::binary-size(sz), ".gt:", rest::binary>> ->
+        [{:float_field, field}, {:range, :gt} | accept(rest, :float)]
+      <<^field::binary-size(sz), ".gte:", rest::binary>> ->
+        [{:float_field, field}, {:range, :gte} | accept(rest, :float)]
+      _ ->
+        accept(r_fields, opts, input, :float_field)
+    end
+  end
+  defp accept([], %{date_fields: fields} = opts, input, :float_field), do: accept(fields, opts, input, :date_field)
+
+  #
+  # Date fields
+  #
+
+  defp accept([field | r_fields], opts, input, :date_field) do
+    sz = field |> byte_size
+
+    case input do
+      <<^field::binary-size(sz), ":", rest::binary>> ->
+        [{:date_field, field}, {:range, :eq} | accept(rest, :date)]
+      <<^field::binary-size(sz), ".eq:", rest::binary>> ->
+        [{:date_field, field}, {:range, :eq} | accept(rest, :date)]
+      <<^field::binary-size(sz), ".lt:", rest::binary>> ->
+        [{:date_field, field}, {:range, :lt} | accept(rest, :date)]
+      <<^field::binary-size(sz), ".lte:", rest::binary>> ->
+        [{:date_field, field}, {:range, :lte} | accept(rest, :date)]
+      <<^field::binary-size(sz), ".gt:", rest::binary>> ->
+        [{:date_field, field}, {:range, :gt} | accept(rest, :date)]
+      <<^field::binary-size(sz), ".gte:", rest::binary>> ->
+        [{:date_field, field}, {:range, :gte} | accept(rest, :date)]
+      _ ->
+        accept(r_fields, opts, input, :date_field)
+    end
+  end
+
+  #
+  # Default field handling
+  #
+
+  defp accept([], %{default_field: field} = opts, input, :date_field) do
+    [{:literal_field, field} | accept(input, :literal)]
+  end
+
+  #
+  # Text and wildcarded text
+  #
+
+  defp accept(input, :literal), do: accept(input, "", :literal)
+
+  defp accept(<<"\\", c::utf8, rest::binary>>, term, :literal), do: accept(rest, term <> <<c::utf8>>, :literal)
+  defp accept(<<c::utf8, rest::binary>>, term, :literal) when c in '*?', do: accept(rest, term <> <<c::utf8>>, :wildcard)
+  defp accept(<<c::utf8, rest::binary>>, term, :literal), do: accept(rest, term <> <<c::utf8>>, :literal)
+  defp accept(<<>>, term, :literal), do: [literal: term]
+
+  defp accept(<<"\\", c::utf8, rest::binary>>, term, :wildcard) when c in '*?', do: accept(rest, term <> <<"\\", c::utf8>>, :wildcard)
+  defp accept(<<"\\", c::utf8, rest::binary>>, term, :wildcard), do: accept(rest, term <> <<c::utf8>>, :wildcard)
+  defp accept(<<c::utf8, rest::binary>>, term, :wildcard), do: accept(rest, term <> <<c::utf8>>, :wildcard)
+  defp accept(<<>>, term, :wildcard), do: [wildcard: term]
+
+  #
+  # Booleans
+  #
+
+  defp accept("true", :boolean), do: [boolean: true]
+  defp accept("false", :boolean), do: [boolean: false]
+  defp accept(input, :boolean), do: raise ArgumentError, "Expected a boolean, got `\#{input}'."
+
+  #
+  # Floats (integers are also considered valid)
+  #
+
+  defp accept(<<"+", rest::binary>>, :float), do: accept(rest, "", :float_w)
+  defp accept(<<"-", rest::binary>>, :float), do: accept(rest, "-", :float_w)
+  defp accept(input, :float), do: accept(input, "", :float_w)
+
+  defp accept(<<c::utf8, rest::binary>>, term, :float_w) when c in ?0..?9, do: accept(rest, term <> <<c::utf8>>, :float_w)
+  defp accept(<<".", rest::binary>>, term, :float_w), do: accept(rest, term <> ".", :float_f)
+  defp accept(<<c::utf8, rest::binary>>, term, :float_w), do: raise ArgumentError, "Expected a float, got `\#{<<term::binary, c::utf8, rest::binary>>}'."
+  defp accept(<<>>, term, :float_w), do: [float: to_number(term)]
+
+  defp accept(<<c::utf8, rest::binary>>, term, :float_f) when c in ?0..?9, do: accept(rest, term <> <<c::utf8>>, :float_f)
+  defp accept(<<c::utf8, rest::binary>>, term, :float_f), do: raise ArgumentError, "Expected a float, got `\#{<<term::binary, c::utf8, rest::binary>>}'."
+  defp accept(<<>>, term, :float_f), do: [float: to_number(term)]
+
+  #
+  # Integers
+  #
+
+  defp accept(<<"+", rest::binary>>, :int), do: accept(rest, "", :int_w)
+  defp accept(<<"-", rest::binary>>, :int), do: accept(rest, "-", :int_w)
+  defp accept(input, :int), do: accept(input, "", :int_w)
+
+  defp accept(<<c::utf8, rest::binary>>, term, :int_w) when c in ?0..?9, do: accept(rest, term <> <<c::utf8>>, :int_w)
+  defp accept(<<c::utf8, rest::binary>>, term, :int_w), do: raise ArgumentError, "Expected an integer, got `\#{<<term::binary, c::utf8, rest::binary>>}'."
+  defp accept(<<>>, term, :int_w), do: [int: to_number(term)]
+
+  #
+  # IP addresses
+  #
+
+  defp accept(<<c1::utf8, c2::utf8, c3::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9 and c2 in ?0..?9 and c3 in ?0..?9, do: accept({})
+  defp accept(<<"::ffff:", c1::utf8, c2::utf8, c3::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9 and c2 in ?0..?9 and c3 in ?0..?9, do: accept({})
+  defp accept(<<c1::utf8, c2::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9 and c2 in ?0..?9, do: accept({})
+  defp accept(<<"::ffff:",c1::utf8, c2::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9 and c2 in ?0..?9, do: accept({})
+  defp accept(<<c1::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9, do: accept({})
+  defp accept(<<"::ffff:", c1::utf8, ".", rest::binary>>, :ip) when c1 in ?0..9, do: accept({})
+
+  defp to_number(term) do
+    {float_val, _} = :string.to_float(term)
+    {int_val, _} = :string.to_integer(term)
+
+    cond do
+      is_float(float_val) ->
+        float_val
+      is_integer(int_val) ->
+        int_val
+      true ->
+        raise ArgumentError, "Expected a number."
+    end
+  end
+end
+"""
\ No newline at end of file
diff --git a/mix.exs b/mix.exs
index f3ceb164..38b82378 100644
--- a/mix.exs
+++ b/mix.exs
@@ -49,7 +49,8 @@ defmodule Philomena.MixProject do
       {:bcrypt_elixir, "~> 2.0"},
       {:pot, "~> 0.10.1"},
       {:secure_compare, "~> 0.1.0"},
-      {:elastix, "~> 0.7.1"}
+      {:elastix, "~> 0.7.1"},
+      {:nimble_parsec, "~> 0.5.1"},
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index c9a7a73f..af277f52 100644
--- a/mix.lock
+++ b/mix.lock
@@ -22,6 +22,7 @@
   "mime": {:hex, :mime, "1.3.1", "30ce04ab3175b6ad0bdce0035cba77bba68b813d523d1aac73d9781b4d193cf8", [:mix], [], "hexpm"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm"},
   "neotoma": {:hex, :neotoma, "1.7.3", "d8bd5404b73273989946e4f4f6d529e5c2088f5fa1ca790b4dbe81f4be408e61", [:rebar], [], "hexpm"},
+  "nimble_parsec": {:hex, :nimble_parsec, "0.5.1", "c90796ecee0289dbb5ad16d3ad06f957b0cd1199769641c961cfe0b97db190e0", [:mix], [], "hexpm"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm"},
   "pbkdf2": {:hex, :pbkdf2, "2.0.0", "11c23279fded5c0027ab3996cfae77805521d7ef4babde2bd7ec04a9086cf499", [:rebar3], [], "hexpm"},
   "phoenix": {:hex, :phoenix, "1.4.9", "746d098e10741c334d88143d3c94cab1756435f94387a63441792e66ec0ee974", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.1", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.8.1 or ~> 1.9", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 1.0 or ~> 2.0", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm"},