Switch from pears to modified party parser

gleam.toml

@@ -11,6 +11,7 @@ links = [
 [dependencies]
 gleam_stdlib = "~> 0.34 or ~> 1.0"
 pears = "~> 0.3"
+party = "~> 1.0"
 
 [dev-dependencies]
 gleeunit = "~> 1.0"

manifest.toml

@@ -4,10 +4,12 @@
 packages = [
   { name = "gleam_stdlib", version = "0.36.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "C0D14D807FEC6F8A08A7C9EF8DFDE6AE5C10E40E21325B2B29365965D82EB3D4" },
   { name = "gleeunit", version = "1.0.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "D364C87AFEB26BDB4FB8A5ABDE67D635DC9FA52D6AB68416044C35B096C6882D" },
+  { name = "party", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "party", source = "hex", outer_checksum = "13D70704E008F1AB163E6E5AED717014473898100B26852E158BD6E9BAE583BC" },
   { name = "pears", version = "0.3.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "pears", source = "hex", outer_checksum = "F823EDF5C7F8606A0B7764C071B6EE8515FC341D6FC69902E81120633DF7E983" },
 ]
 
 [requirements]
 gleam_stdlib = { version = "~> 0.34 or ~> 1.0" }
 gleeunit = { version = "~> 1.0" }
+party = { version = "~> 1.0"}
 pears = { version = "~> 0.3" }

src/jasper.gleam

@@ -2,34 +2,23 @@ import gleam/float
 import gleam/int
 import gleam/string
 import gleam/result
-import gleam/option.{None, Some}
 import gleam/dict.{type Dict}
 import gleam/list
-import pears.{type Parser}
+import jasper/internal/parsing.{
-import pears/chars.{type Char, digit, string}
+  type ParseError, type Parser, Parser, Position, Unexpected, between, char,
-import pears/combinators.{
+  choice, choice_char, concat, digit, do, either, end, go, lazy, left, letter,
-  alt, between, choice, eof, just, lazy, left, many0, many1, map, maybe, none_of,
+  many, many1_concat, many_concat, map, pair, perhaps, perhaps_default,
-  one_of, pair, recognize, right, sep_by0, seq, to,
+  perhaps_empty, return, right, satisfy, sep, string, to,
 }
 
-pub type ParseError {
+pub type JsonParseError =
-  UnexpectedToken(found: Char)
+  Nil
-  UnexpectedEndOfInput
-}
 
-fn run_parser(
+pub type JsonParserError =
-  input: String,
+  ParseError(JsonParseError)
-  parser: pears.Parser(Char, a),
+
-) -> Result(a, ParseError) {
+pub type JsonParser(a) =
-  case parser(chars.input(input)) {
+  Parser(a, JsonParseError)
-    Ok(pears.Parsed(_, j)) -> Ok(j)
-    Error(e) ->
-      Error(case e {
-        pears.UnexpectedToken(_, _, f) -> UnexpectedToken(f)
-        pears.UnexpectedEndOfInput(_, _) -> UnexpectedEndOfInput
-      })
-  }
-}
 
 pub type JsonObject =
   Dict(String, JsonValue)
@@ -46,129 +35,417 @@ pub type JsonValue {
   Null
 }
 
-fn ws0() -> Parser(Char, List(Char)) {
+fn ws(options: JsonParseOptions) -> JsonParser(String) {
-  one_of([" ", "\n", "\r", "\t"])
+  many_concat(
-  |> many0()
+    satisfy(fn(c) {
+      string.contains(
+        case options.ecma_whitespace {
+          True ->
+            " \n\r\t\u{000B}\u{000C}\u{00A0}\u{2028}\u{2029}\u{FEFF}\u{1680}\u{2000}\u{2001}\u{2002}\u{2003}\u{2004}\u{2005}\u{2006}\u{2007}\u{2008}\u{2009}\u{200A}\u{202F}\u{205F}\u{3000}"
+          False -> " \n\r\t"
+        },
+        c,
+      )
+    }),
+  )
 }
 
-fn padded(p: Parser(_, a)) {
+fn padded(p: JsonParser(a), options: JsonParseOptions) -> JsonParser(a) {
-  left(p, ws0())
+  left(p, ws(options))
 }
 
-fn symbol(s: String) {
+fn symbol(s: String, options: JsonParseOptions) -> JsonParser(String) {
-  padded(string(s))
+  char(s)
+  |> padded(options)
 }
 
-fn value_parser() -> Parser(Char, JsonValue) {
+fn json_null_parser() -> JsonParser(Nil) {
-  let hex_digit =
+  string("null")
-    one_of([
+  |> to(Nil)
-      "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e",
+}
-      "f", "A", "B", "C", "D", "E", "F",
-    ])
 
-  let unicode_escape_digits =
+fn json_boolean_parser() -> JsonParser(Bool) {
-    recognize(seq([hex_digit, hex_digit, hex_digit, hex_digit]))
+  either(to(string("true"), True), to(string("false"), False))
+}
+
+fn hex_digit_parser() -> JsonParser(String) {
+  choice_char([
+    "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e",
+    "f", "A", "B", "C", "D", "E", "F",
+  ])
+}
+
+fn json_number_parser(options: JsonParseOptions) -> JsonParser(Float) {
+  let sign_parser =
+    either(char("+"), char("-"))
+    |> perhaps_empty
+  let int_parser =
+    either(
+      char("0"),
+      concat(
+        choice_char(["1", "2", "3", "4", "5", "6", "7", "8", "9"]),
+        many_concat(digit()),
+      ),
+    )
+  let exp_parser =
+    either(char("e"), char("E"))
+    |> concat(sign_parser)
+    |> concat(many1_concat(digit()))
+    |> perhaps_empty
+  let min_double = -1.7976931348623158e308
+  let max_double = 1.7976931348623158e308
+
+  case options.ecma_numbers {
+    True -> {
+      use sign <- do(sign_parser)
+      let inf = case sign {
+        "-" -> min_double
+        _ -> max_double
+      }
+      choice([
+        to(string("Infinity"), inf),
+        to(string("NaN"), 0.0),
+        {
+          use hex <- do(
+            either(string("0x"), string("0X"))
+            |> right(many1_concat(hex_digit_parser())),
+          )
+          let assert Ok(n) = int.base_parse(sign <> hex, 16)
+          return(int.to_float(n))
+        },
+        {
+          use n <- do(either(
+            {
+              use ns <- do(int_parser)
+              use ds <- do(
+                right(
+                  char("."),
+                  many1_concat(digit())
+                    |> perhaps_default("0"),
+                )
+                |> perhaps_default("0"),
+              )
+              return(ns <> "." <> ds)
+            },
+            concat(to(char("."), "0."), many1_concat(digit())),
+          ))
+          use ex <- do(exp_parser)
+          { sign <> n <> ex }
+          |> float.parse
+          |> result.unwrap(inf)
+          |> return
+        },
+      ])
+    }
+    False -> {
+      use sign <- do(
+        char("-")
+        |> perhaps_empty,
+      )
+      let inf = case sign {
+        "-" -> min_double
+        _ -> max_double
+      }
+      use ns <- do(int_parser)
+      use ds <- do(
+        right(char("."), many1_concat(digit()))
+        |> perhaps_default("0"),
+      )
+      use ex <- do(exp_parser)
+      { sign <> ns <> "." <> ds <> ex }
+      |> float.parse
+      |> result.unwrap(inf)
+      |> return
+    }
+  }
+}
+
+fn string_to_codepoint(value: String) -> String {
+  let assert Ok(number) = int.base_parse(value, 16)
+  let assert Ok(codepoint) = string.utf_codepoint(number)
+  string.from_utf_codepoints([codepoint])
+}
+
+fn valid_string_char(c: String) -> Bool {
+  let assert [p] = string.to_utf_codepoints(c)
+  let i = string.utf_codepoint_to_int(p)
+  i >= 0x20 && i <= 0x10FFFF
+}
+
+fn json_string_parser(options: JsonParseOptions) -> JsonParser(String) {
+  let hex_digit = hex_digit_parser()
+  let unicode_escape =
+    map(
+      right(
+        char("u"),
+        hex_digit
+          |> concat(hex_digit)
+          |> concat(hex_digit)
+          |> concat(hex_digit),
+      ),
+      string_to_codepoint,
+    )
 
   let escape =
-    just("\\")
+    char("\\")
     |> right(
-      choice([
+      choice(case options.ecma_strings {
-        just("\\"),
+        True -> [
-        just("/"),
+          map(
-        just("\""),
+            right(char("x"), concat(hex_digit, hex_digit)),
-        to(just("b"), "\u{0008}"),
+            string_to_codepoint,
-        to(just("f"), "\u{000C}"),
+          ),
-        to(just("n"), "\n"),
+          unicode_escape,
-        to(just("r"), "\r"),
+          char("\\"),
-        to(just("t"), "\t"),
+          char("/"),
-        map(right(just("u"), unicode_escape_digits), fn(value) {
+          char("'"),
-          let assert Ok(number) = int.base_parse(string.concat(value), 16)
+          char("\""),
-          let assert Ok(codepoint) = string.utf_codepoint(number)
+          to(char("b"), "\u{0008}"),
-          string.from_utf_codepoints([codepoint])
+          to(char("f"), "\u{000C}"),
-        }),
+          to(char("n"), "\n"),
-      ]),
+          to(char("r"), "\r"),
+          to(char("t"), "\t"),
+          to(char("v"), "\u{000B}"),
+          to(char("0"), "\u{0000}"),
+          to(
+            choice([
+              string("\r\n"),
+              char("\r"),
+              char("\n"),
+              char("\u{2028}"),
+              char("\u{2029}"),
+            ]),
+            "",
+          ),
+          satisfy(fn(c) { !string.contains("123456789", c) }),
+        ]
+        False -> [
+          unicode_escape,
+          char("\\"),
+          char("/"),
+          char("\""),
+          to(char("b"), "\u{0008}"),
+          to(char("f"), "\u{000C}"),
+          to(char("n"), "\n"),
+          to(char("r"), "\r"),
+          to(char("t"), "\t"),
+        ]
+      }),
     )
 
-  let str =
+  let str = fn(q) {
-    none_of(["\"", "\\"])
+    satisfy(fn(c) { c != q && c != "\\" && valid_string_char(c) })
-    |> alt(escape)
+    |> either(escape)
-    |> many0()
+    |> many_concat()
-    |> map(string.concat)
+    |> between(char(q), char(q))
-    |> between(just("\""), just("\""))
+  }
 
-  let value = lazy(value_parser)
+  case options.ecma_strings {
+    True -> either(str("\""), str("'"))
+    False -> str("\"")
+  }
+}
 
-  let num =
+fn parse_multiline_comment() -> JsonParser(String) {
-    maybe(just("-"))
+  Parser(fn(source, pos) {
-    |> pair(
+    let assert Position(row, col) = pos
-      alt(
+    case source {
-        to(just("0"), ["0"]),
+      [h, ..t] ->
-        recognize(pair(
+        case h {
-          one_of(["1", "2", "3", "4", "5", "6", "7", "8", "9"]),
+          "\n" -> Ok(#(h, t, Position(row + 1, 0)))
-          many0(digit()),
+          "*" ->
-        )),
+            case t {
-      )
+              ["/", ..] -> Error(Unexpected(pos, h))
-      |> map(string.concat),
+              _ -> Ok(#(h, t, Position(row, col + 1)))
-    )
+            }
-    |> pair(maybe(
+          _ -> Ok(#(h, t, Position(row, col + 1)))
-      just(".")
-      |> right(many1(digit()))
-      |> map(string.concat),
-    ))
-    |> pair(
-      recognize(maybe(
-        alt(just("e"), just("E"))
-        |> pair(maybe(one_of(["+", "-"])))
-        |> pair(many1(digit())),
-      ))
-      |> map(string.concat),
-    )
-    |> map(fn(p) {
-      case p {
-        #(#(#(neg, ns), ds), ex) -> {
-          {
-            option.unwrap(neg, "") <> ns <> "." <> option.unwrap(ds, "0") <> ex
-          }
-          |> float.parse
-          |> result.unwrap(case neg {
-            Some(_) -> -1.7976931348623158e308
-            None -> 1.7976931348623158e308
-          })
-          |> Number
         }
-      }
+      [] -> Error(Unexpected(pos, "EOF"))
-    })
+    }
-
+  })
-  let bool =
+  |> many_concat
-    alt(to(string("true"), Boolean(True)), to(string("false"), Boolean(False)))
+  |> between(string("/*"), string("*/"))
-
-  let null = to(string("null"), Null)
-
-  let array =
-    sep_by0(value, symbol(","))
-    |> between(symbol("["), symbol("]"))
-    |> map(Array)
-
-  let obj =
-    str
-    |> left(symbol(":"))
-    |> pair(value)
-    |> sep_by0(symbol(","))
-    |> map(dict.from_list)
-    |> between(symbol("{"), symbol("}"))
-    |> map(Object)
-
-  choice([num, bool, null, map(str, String), array, obj])
-  |> padded()
 }
 
-fn json_parser() -> Parser(Char, JsonValue) {
+fn parse_singleline_comment() -> JsonParser(String) {
-  value_parser()
+  right(
-  |> between(ws0(), eof())
+    string("//"),
+    many_concat(satisfy(fn(c) { !string.contains("\r\n\u{2028}\u{2029}", c) })),
+  )
 }
 
-pub fn parse_json(value: String) -> Result(JsonValue, ParseError) {
+fn comment_parser(options: JsonParseOptions) -> JsonParser(String) {
-  run_parser(value, json_parser())
+  either(parse_multiline_comment(), parse_singleline_comment())
+  |> padded(options)
+}
+
+fn allow_comments(options: JsonParseOptions, p: Parser(_, _)) {
+  case options.comments {
+    True -> left(p, many(comment_parser(options)))
+    False -> p
+  }
+}
+
+fn allow_trailing_comma(options: JsonParseOptions, p: Parser(_, _)) {
+  case options.trailing_comma {
+    True -> right(perhaps(symbol(",", options)), p)
+    False -> p
+  }
+}
+
+fn json_array_parser(options: JsonParseOptions) -> JsonParser(JsonArray) {
+  let json_value_parser = lazy(fn() { json_value_parser(options) })
+  let allow_comments = allow_comments(options, _)
+  sep(json_value_parser, allow_comments(symbol(",", options)))
+  |> between(
+    allow_comments(symbol("[", options)),
+    allow_trailing_comma(options, symbol("]", options)),
+  )
+}
+
+// todo
+fn ecmascript_identifier_parser() -> JsonParser(String) {
+  letter()
+  |> concat(
+    either(letter(), digit())
+    |> many_concat,
+  )
+}
+
+fn json_object_parser(options: JsonParseOptions) -> JsonParser(JsonObject) {
+  let json_value_parser = lazy(fn() { json_value_parser(options) })
+  let allow_comments = allow_comments(options, _)
+  let key_parser = case options.ecma_object_keys {
+    True -> either(json_string_parser(options), ecmascript_identifier_parser())
+    False -> json_string_parser(options)
+  }
+  allow_comments(key_parser)
+  |> left(allow_comments(symbol(":", options)))
+  |> pair(json_value_parser)
+  |> sep(allow_comments(symbol(",", options)))
+  |> map(dict.from_list)
+  |> between(
+    allow_comments(symbol("{", options)),
+    allow_trailing_comma(options, symbol("}", options)),
+  )
+}
+
+fn json_value_parser(options: JsonParseOptions) -> JsonParser(JsonValue) {
+  choice([
+    to(json_null_parser(), Null),
+    map(json_boolean_parser(), Boolean),
+    map(json_number_parser(options), Number),
+    map(json_string_parser(options), String),
+    map(json_array_parser(options), Array),
+    map(json_object_parser(options), Object),
+  ])
+  |> padded(options)
+  |> allow_comments(options, _)
+}
+
+fn json_parser(options: JsonParseOptions) -> JsonParser(JsonValue) {
+  json_value_parser(options)
+  |> between(allow_comments(options, ws(options)), end())
+}
+
+import gleam/io
+
+pub fn main() {
+  //   io.debug(parse_jsonc(
+  //     " /* asdf */  [1 ,  // asdf \n 2/* asdf */, { \"k\"/* asdf */ :// asdf\n 3}]",
+  //   ))
+  //   io.debug(parse_jsonc(
+  //     "{
+  //   \"foo\":/* * / */ \"121234\",
+  //   \"foo\":/* *//* /*** */ \"121234\"
+  // } // asdf",
+  //   ))
+  io.debug(parse_json5("{bar: -0x14,\"foo\": \"a\\x23\\\r\nsd\\Af\",}"))
+}
+
+pub type JsonParseOptions {
+  JsonParseOptions(
+    comments: Bool,
+    trailing_comma: Bool,
+    ecma_object_keys: Bool,
+    ecma_strings: Bool,
+    ecma_numbers: Bool,
+    ecma_whitespace: Bool,
+  )
+}
+
+const json_options = JsonParseOptions(
+  comments: False,
+  trailing_comma: False,
+  ecma_object_keys: False,
+  ecma_strings: False,
+  ecma_numbers: False,
+  ecma_whitespace: False,
+)
+
+const jsonc_options = JsonParseOptions(
+  comments: True,
+  trailing_comma: False,
+  ecma_object_keys: False,
+  ecma_strings: False,
+  ecma_numbers: False,
+  ecma_whitespace: False,
+)
+
+const json5_options = JsonParseOptions(
+  comments: True,
+  trailing_comma: True,
+  ecma_object_keys: True,
+  ecma_strings: True,
+  ecma_numbers: True,
+  ecma_whitespace: True,
+)
+
+const jsonl_options = json_options
+
+pub fn parse_json_custom(
+  value: String,
+  options: JsonParseOptions,
+) -> Result(JsonValue, JsonParserError) {
+  go(json_parser(options), value)
+}
+
+pub fn parse_json(value: String) -> Result(JsonValue, JsonParserError) {
+  parse_json_custom(value, json_options)
+}
+
+pub fn parse_jsonc(value: String) -> Result(JsonValue, JsonParserError) {
+  parse_json_custom(value, jsonc_options)
+}
+
+pub fn parse_json5(value: String) -> Result(JsonValue, JsonParserError) {
+  parse_json_custom(value, json5_options)
+}
+
+fn split_jsonl(value: String) -> List(String) {
+  case string.last(value) {
+    Ok("\n") -> string.drop_right(value, 1)
+    _ -> value
+  }
+  |> string.split("\n")
+}
+
+pub fn parse_jsonl(value: String) -> Result(List(JsonValue), JsonParserError) {
+  let parse = go(json_parser(jsonl_options), _)
+  list.try_map(split_jsonl(value), parse)
+}
+
+pub fn parse_jsonl_all(
+  value: String,
+) -> List(Result(JsonValue, JsonParserError)) {
+  let parse = go(json_parser(jsonl_options), _)
+  list.map(split_jsonl(value), parse)
+}
+
+pub fn parse_jsonl_valid(value: String) -> List(JsonValue) {
+  value
+  |> parse_jsonl_all
+  |> result.values
 }
 
 fn stringify_json_spaced_rec(
@@ -269,213 +546,188 @@ pub fn stringify_jsonl(values: List(JsonValue)) -> String {
   |> list.map(stringify_json)
   |> string.join("\n")
 }
+// pub type JsonQuery {
+//   Root
+//   Key(query: JsonQuery, key: String)
+//   KeyOr(query: JsonQuery, key: String, or: JsonValue)
+//   Index(query: JsonQuery, index: Int)
+//   IndexOr(query: JsonQuery, index: Int, or: JsonValue)
+//   Filter(query: JsonQuery, predicate: fn(JsonValue) -> Bool)
+//   Map(query: JsonQuery, mapping: fn(JsonValue) -> JsonValue)
+//   MapKeys(query: JsonQuery, mapping: fn(String) -> String)
+//   MapValues(query: JsonQuery, mapping: fn(String, JsonValue) -> JsonValue)
+//   FilterMap(query: JsonQuery, mapping: fn(JsonValue) -> Result(JsonValue, Nil))
+//   ForEach(query: JsonQuery)
+//   ForEachOk(query: JsonQuery)
+// }
 
-fn split_jsonl(value: String) -> List(String) {
+// type InvJsonQuery {
-  case string.last(value) {
+//   InvEnd
-    Ok("\n") -> string.drop_right(value, 1)
+//   InvKey(key: String, query: InvJsonQuery)
-    _ -> value
+//   InvKeyOr(key: String, or: JsonValue, query: InvJsonQuery)
-  }
+//   InvIndex(index: Int, query: InvJsonQuery)
-  |> string.split("\n")
+//   InvIndexOr(index: Int, or: JsonValue, query: InvJsonQuery)
-}
+//   InvFilter(predicate: fn(JsonValue) -> Bool, query: InvJsonQuery)
+//   InvMap(mapping: fn(JsonValue) -> JsonValue, query: InvJsonQuery)
+//   InvMapKeys(mapping: fn(String) -> String, query: InvJsonQuery)
+//   InvMapValues(mapping: fn(String, JsonValue) -> JsonValue, query: InvJsonQuery)
+//   InvFilterMap(
+//     mapping: fn(JsonValue) -> Result(JsonValue, Nil),
+//     query: InvJsonQuery,
+//   )
+//   InvForEach(query: InvJsonQuery)
+//   InvForEachOk(query: InvJsonQuery)
+// }
 
-pub fn parse_jsonl(value: String) -> Result(List(JsonValue), ParseError) {
+// fn invert_query_rec(query: JsonQuery, state: InvJsonQuery) -> InvJsonQuery {
-  let parse = run_parser(_, json_parser())
+//   case query {
-  list.try_map(split_jsonl(value), parse)
+//     Root -> state
-}
+//     Key(query, key) -> invert_query_rec(query, InvKey(key, state))
+//     KeyOr(query, key, o) -> invert_query_rec(query, InvKeyOr(key, o, state))
+//     Index(query, index) -> invert_query_rec(query, InvIndex(index, state))
+//     IndexOr(query, index, or) ->
+//       invert_query_rec(query, InvIndexOr(index, or, state))
+//     Filter(query, predicate) ->
+//       invert_query_rec(query, InvFilter(predicate, state))
+//     Map(query, mapping) -> invert_query_rec(query, InvMap(mapping, state))
+//     MapKeys(query, mapping) ->
+//       invert_query_rec(query, InvMapKeys(mapping, state))
+//     MapValues(query, mapping) ->
+//       invert_query_rec(query, InvMapValues(mapping, state))
+//     FilterMap(query, mapping) ->
+//       invert_query_rec(query, InvFilterMap(mapping, state))
+//     ForEach(query) -> invert_query_rec(query, InvForEach(state))
+//     ForEachOk(query) -> invert_query_rec(query, InvForEachOk(state))
+//   }
+// }
 
-pub fn parse_jsonl_all(value: String) -> List(Result(JsonValue, ParseError)) {
+// fn invert_query(query: JsonQuery) -> InvJsonQuery {
-  let parse = run_parser(_, json_parser())
+//   invert_query_rec(query, InvEnd)
-  list.map(split_jsonl(value), parse)
+// }
-}
 
-pub fn parse_jsonl_valid(value: String) -> List(JsonValue) {
+// pub type JsonQueryError {
-  value
+//   UnexpectedType(JsonValue)
-  |> parse_jsonl_all
+//   MissingObjectKey(JsonValue, key: String)
-  |> result.values
+//   IndexOutOfBounds(JsonValue, index: Int)
-}
+// }
 
-pub type JsonQuery {
+// fn query_json_rec(
-  Root
+//   json: JsonValue,
-  Key(query: JsonQuery, key: String)
+//   query: InvJsonQuery,
-  KeyOr(query: JsonQuery, key: String, or: JsonValue)
+// ) -> Result(JsonValue, JsonQueryError) {
-  Index(query: JsonQuery, index: Int)
+//   case query {
-  IndexOr(query: JsonQuery, index: Int, or: JsonValue)
+//     InvEnd -> Ok(json)
-  Filter(query: JsonQuery, predicate: fn(JsonValue) -> Bool)
+//     InvKey(key, q) ->
-  Map(query: JsonQuery, mapping: fn(JsonValue) -> JsonValue)
+//       case json {
-  MapKeys(query: JsonQuery, mapping: fn(String) -> String)
+//         Object(obj) as j ->
-  MapValues(query: JsonQuery, mapping: fn(String, JsonValue) -> JsonValue)
+//           obj
-  FilterMap(query: JsonQuery, mapping: fn(JsonValue) -> Result(JsonValue, Nil))
+//           |> dict.get(key)
-  ForEach(query: JsonQuery)
+//           |> result.replace_error(MissingObjectKey(j, key))
-  ForEachOk(query: JsonQuery)
+//         j -> Error(UnexpectedType(j))
-}
+//       }
+//       |> result.map(query_json_rec(_, q))
+//       |> result.flatten
+//     InvKeyOr(key, or, q) ->
+//       case json {
+//         Object(obj) ->
+//           obj
+//           |> dict.get(key)
+//           |> result.unwrap(or)
+//           |> Ok
+//         j -> Error(UnexpectedType(j))
+//       }
+//       |> result.map(query_json_rec(_, q))
+//       |> result.flatten
+//     InvIndex(index, q) ->
+//       case json {
+//         Array(arr) as j ->
+//           arr
+//           |> list.at(index)
+//           |> result.replace_error(IndexOutOfBounds(j, index))
+//         j -> Error(UnexpectedType(j))
+//       }
+//       |> result.map(query_json_rec(_, q))
+//       |> result.flatten
+//     InvIndexOr(index, or, q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.at(index)
+//           |> result.unwrap(or)
+//           |> Ok
+//         j -> Error(UnexpectedType(j))
+//       }
+//       |> result.map(query_json_rec(_, q))
+//       |> result.flatten
+//     InvFilter(predicate, q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.filter(predicate)
+//           |> Array
+//           |> query_json_rec(q)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvMap(mapping, q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.map(mapping)
+//           |> Array
+//           |> query_json_rec(q)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvMapKeys(mapping, q) ->
+//       case json {
+//         Object(obj) ->
+//           obj
+//           |> dict.to_list
+//           |> list.map(fn(kv) { #(mapping(kv.0), kv.1) })
+//           |> dict.from_list
+//           |> Object
+//           |> query_json_rec(q)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvMapValues(mapping, q) ->
+//       case json {
+//         Object(obj) ->
+//           obj
+//           |> dict.map_values(mapping)
+//           |> Object
+//           |> query_json_rec(q)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvFilterMap(mapping, q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.filter_map(mapping)
+//           |> Array
+//           |> query_json_rec(q)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvForEach(q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.map(query_json_rec(_, q))
+//           |> result.all
+//           |> result.map(Array)
+//         j -> Error(UnexpectedType(j))
+//       }
+//     InvForEachOk(q) ->
+//       case json {
+//         Array(arr) ->
+//           arr
+//           |> list.map(query_json_rec(_, q))
+//           |> result.values
+//           |> Array
+//           |> Ok
+//         j -> Error(UnexpectedType(j))
+//       }
+//   }
+// }
 
-type InvJsonQuery {
+// pub fn query_json(json: JsonValue, query: JsonQuery) {
-  InvEnd
+//   query_json_rec(json, invert_query(query))
-  InvKey(key: String, query: InvJsonQuery)
+// }
-  InvKeyOr(key: String, or: JsonValue, query: InvJsonQuery)
-  InvIndex(index: Int, query: InvJsonQuery)
-  InvIndexOr(index: Int, or: JsonValue, query: InvJsonQuery)
-  InvFilter(predicate: fn(JsonValue) -> Bool, query: InvJsonQuery)
-  InvMap(mapping: fn(JsonValue) -> JsonValue, query: InvJsonQuery)
-  InvMapKeys(mapping: fn(String) -> String, query: InvJsonQuery)
-  InvMapValues(mapping: fn(String, JsonValue) -> JsonValue, query: InvJsonQuery)
-  InvFilterMap(
-    mapping: fn(JsonValue) -> Result(JsonValue, Nil),
-    query: InvJsonQuery,
-  )
-  InvForEach(query: InvJsonQuery)
-  InvForEachOk(query: InvJsonQuery)
-}
-
-fn invert_query_rec(query: JsonQuery, state: InvJsonQuery) -> InvJsonQuery {
-  case query {
-    Root -> state
-    Key(query, key) -> invert_query_rec(query, InvKey(key, state))
-    KeyOr(query, key, o) -> invert_query_rec(query, InvKeyOr(key, o, state))
-    Index(query, index) -> invert_query_rec(query, InvIndex(index, state))
-    IndexOr(query, index, or) ->
-      invert_query_rec(query, InvIndexOr(index, or, state))
-    Filter(query, predicate) ->
-      invert_query_rec(query, InvFilter(predicate, state))
-    Map(query, mapping) -> invert_query_rec(query, InvMap(mapping, state))
-    MapKeys(query, mapping) ->
-      invert_query_rec(query, InvMapKeys(mapping, state))
-    MapValues(query, mapping) ->
-      invert_query_rec(query, InvMapValues(mapping, state))
-    FilterMap(query, mapping) ->
-      invert_query_rec(query, InvFilterMap(mapping, state))
-    ForEach(query) -> invert_query_rec(query, InvForEach(state))
-    ForEachOk(query) -> invert_query_rec(query, InvForEachOk(state))
-  }
-}
-
-fn invert_query(query: JsonQuery) -> InvJsonQuery {
-  invert_query_rec(query, InvEnd)
-}
-
-pub type JsonQueryError {
-  UnexpectedType(JsonValue)
-  MissingObjectKey(JsonValue, key: String)
-  IndexOutOfBounds(JsonValue, index: Int)
-}
-
-fn query_json_rec(
-  json: JsonValue,
-  query: InvJsonQuery,
-) -> Result(JsonValue, JsonQueryError) {
-  case query {
-    InvEnd -> Ok(json)
-    InvKey(key, q) ->
-      case json {
-        Object(obj) as j ->
-          obj
-          |> dict.get(key)
-          |> result.replace_error(MissingObjectKey(j, key))
-        j -> Error(UnexpectedType(j))
-      }
-      |> result.map(query_json_rec(_, q))
-      |> result.flatten
-    InvKeyOr(key, or, q) ->
-      case json {
-        Object(obj) ->
-          obj
-          |> dict.get(key)
-          |> result.unwrap(or)
-          |> Ok
-        j -> Error(UnexpectedType(j))
-      }
-      |> result.map(query_json_rec(_, q))
-      |> result.flatten
-    InvIndex(index, q) ->
-      case json {
-        Array(arr) as j ->
-          arr
-          |> list.at(index)
-          |> result.replace_error(IndexOutOfBounds(j, index))
-        j -> Error(UnexpectedType(j))
-      }
-      |> result.map(query_json_rec(_, q))
-      |> result.flatten
-    InvIndexOr(index, or, q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.at(index)
-          |> result.unwrap(or)
-          |> Ok
-        j -> Error(UnexpectedType(j))
-      }
-      |> result.map(query_json_rec(_, q))
-      |> result.flatten
-    InvFilter(predicate, q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.filter(predicate)
-          |> Array
-          |> query_json_rec(q)
-        j -> Error(UnexpectedType(j))
-      }
-    InvMap(mapping, q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.map(mapping)
-          |> Array
-          |> query_json_rec(q)
-        j -> Error(UnexpectedType(j))
-      }
-    InvMapKeys(mapping, q) ->
-      case json {
-        Object(obj) ->
-          obj
-          |> dict.to_list
-          |> list.map(fn(kv) { #(mapping(kv.0), kv.1) })
-          |> dict.from_list
-          |> Object
-          |> query_json_rec(q)
-        j -> Error(UnexpectedType(j))
-      }
-    InvMapValues(mapping, q) ->
-      case json {
-        Object(obj) ->
-          obj
-          |> dict.map_values(mapping)
-          |> Object
-          |> query_json_rec(q)
-        j -> Error(UnexpectedType(j))
-      }
-    InvFilterMap(mapping, q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.filter_map(mapping)
-          |> Array
-          |> query_json_rec(q)
-        j -> Error(UnexpectedType(j))
-      }
-    InvForEach(q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.map(query_json_rec(_, q))
-          |> result.all
-          |> result.map(Array)
-        j -> Error(UnexpectedType(j))
-      }
-    InvForEachOk(q) ->
-      case json {
-        Array(arr) ->
-          arr
-          |> list.map(query_json_rec(_, q))
-          |> result.values
-          |> Array
-          |> Ok
-        j -> Error(UnexpectedType(j))
-      }
-  }
-}
-
-pub fn query_json(json: JsonValue, query: JsonQuery) {
-  query_json_rec(json, invert_query(query))
-}

src/jasper/internal/parsing.gleam

@@ -0,0 +1,417 @@
+import gleam/string
+import gleam/result
+import gleam/list
+
+/// The custom error type for the parser, 
+/// which can itself be parameterized by a user-defined error type.
+/// The user-defined error type is useful for, for example, 
+/// adding a `int.parse` call into your parser pipeline.
+/// See `try` for using this feature.
+pub type ParseError(e) {
+  Unexpected(pos: Position, error: String)
+  UserError(pos: Position, error: e)
+}
+
+/// The type for positions within a string.
+pub type Position {
+  Position(row: Int, col: Int)
+}
+
+/// The parser type, parameterized by the type it parses and 
+/// the user-defined error type it can return.
+pub type Parser(a, e) {
+  Parser(
+    parse: fn(List(String), Position) ->
+      Result(#(a, List(String), Position), ParseError(e)),
+  )
+}
+
+/// Apply a parser to a list of graphemes (holding on to extra result info that is hidden from the library user).
+fn run(
+  p: Parser(a, e),
+  src: List(String),
+  pos: Position,
+) -> Result(#(a, List(String), Position), ParseError(e)) {
+  case p {
+    Parser(f) -> f(src, pos)
+  }
+}
+
+/// Apply a parser to a string.
+pub fn go(p: Parser(a, e), src: String) -> Result(a, ParseError(e)) {
+  case run(p, string.to_graphemes(src), Position(1, 1)) {
+    Ok(#(x, _, _)) -> Ok(x)
+    Error(e) -> Error(e)
+  }
+}
+
+/// Get the current parser position.
+pub fn pos() -> Parser(Position, e) {
+  Parser(fn(source, p) { Ok(#(p, source, p)) })
+}
+
+/// Parse a character if it matches the predicate.
+pub fn satisfy(when pred: fn(String) -> Bool) -> Parser(String, e) {
+  Parser(fn(source, pos) {
+    let assert Position(row, col) = pos
+    case source {
+      [h, ..t] ->
+        case pred(h) {
+          True ->
+            case h {
+              "\n" -> Ok(#(h, t, Position(row + 1, 0)))
+              _ -> Ok(#(h, t, Position(row, col + 1)))
+            }
+          False -> Error(Unexpected(pos, h))
+        }
+      [] -> Error(Unexpected(pos, "EOF"))
+    }
+  })
+}
+
+/// Parse a lowercase letter.
+pub fn lowercase_letter() -> Parser(String, e) {
+  satisfy(when: fn(c) { string.contains("abcdefghijklmnopqrstuvwxyz", c) })
+}
+
+/// Parse an uppercase letter.
+pub fn uppercase_letter() -> Parser(String, e) {
+  satisfy(when: fn(c) { string.contains("ABCDEFGHIJKLMNOPQRSTUVWXYZ", c) })
+}
+
+/// Parse a lowercase or uppercase letter.
+pub fn letter() -> Parser(String, e) {
+  either(lowercase_letter(), uppercase_letter())
+}
+
+/// Parse a specific character.
+pub fn char(c) -> Parser(String, e) {
+  satisfy(when: fn(c2) { c == c2 })
+}
+
+/// Parse a digit.
+pub fn digit() -> Parser(String, e) {
+  satisfy(fn(c) { string.contains("0123456789", c) })
+}
+
+/// Parse a sequence of digits.
+pub fn digits() -> Parser(String, e) {
+  many1_concat(digit())
+}
+
+/// Parse the first parser, or the second if the first fails.
+pub fn either(p: Parser(a, e), q: Parser(a, e)) -> Parser(a, e) {
+  Parser(fn(source, pos) { result.or(run(p, source, pos), run(q, source, pos)) })
+}
+
+/// Parse with the first parser in the list that doesn't fail.
+pub fn choice(ps: List(Parser(a, e))) -> Parser(a, e) {
+  Parser(fn(source, pos) {
+    case ps {
+      [] -> panic as "choice doesn't accept an empty list of parsers"
+      // TODO: should this be an Unexpected instead?
+      [p] -> run(p, source, pos)
+      [p, ..t] ->
+        case run(p, source, pos) {
+          Ok(#(x, r, pos2)) -> Ok(#(x, r, pos2))
+          Error(_) -> run(choice(t), source, pos)
+        }
+    }
+  })
+}
+
+/// Parse an alphanumeric character.
+pub fn alphanum() -> Parser(String, e) {
+  either(digit(), letter())
+}
+
+/// Parse zero or more whitespace characters.
+pub fn whitespace() -> Parser(String, e) {
+  many_concat(choice([char(" "), char("\t"), char("\n")]))
+}
+
+/// Parse one or more whitespace characters.
+pub fn whitespace1() -> Parser(String, e) {
+  many1_concat(choice([char(" "), char("\t"), char("\n")]))
+}
+
+/// Keep trying the parser until it fails, and return the array of parsed results.
+/// This cannot fail because it parses zero or more times!
+pub fn many(p: Parser(a, e)) -> Parser(List(a), e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Error(_) -> Ok(#([], source, pos))
+      Ok(#(x, r, pos2)) ->
+        result.map(run(many(p), r, pos2), fn(res) {
+          #([x, ..res.0], res.1, res.2)
+        })
+    }
+  })
+}
+
+/// Parse a certain string as many times as possible, returning everything that was parsed.
+/// This cannot fail because it parses zero or more times!
+pub fn many_concat(p: Parser(String, e)) -> Parser(String, e) {
+  many(p)
+  |> map(string.concat)
+}
+
+/// Keep trying the parser until it fails, and return the array of parsed results.
+/// This can fail, because it must parse successfully at least once!
+pub fn many1(p: Parser(a, e)) -> Parser(List(a), e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Error(e) -> Error(e)
+      Ok(#(x, r, pos2)) ->
+        result.map(run(many(p), r, pos2), fn(res) {
+          #([x, ..res.0], res.1, res.2)
+        })
+    }
+  })
+}
+
+/// Parse a certain string as many times as possible, returning everything that was parsed.
+/// This can fail, because it must parse successfully at least once!
+pub fn many1_concat(p: Parser(String, e)) -> Parser(String, e) {
+  many1(p)
+  |> map(string.concat)
+}
+
+/// Do the first parser, ignore its result, then do the second parser.
+pub fn seq(p: Parser(a, e), q: Parser(b, e)) -> Parser(b, e) {
+  use _ <- do(p)
+  q
+}
+
+/// Parse a sequence separated by the given separator parser.
+pub fn sep(parser: Parser(a, e), by s: Parser(b, e)) -> Parser(List(a), e) {
+  use mb_a <- do(perhaps(parser))
+  case mb_a {
+    Ok(a) -> {
+      use rest <- do(many(right(s, parser)))
+      return([a, ..rest])
+    }
+    Error(Nil) -> return([])
+  }
+}
+
+/// Parse a sequence separated by the given separator parser.
+/// This only succeeds if at least one element of the sequence was parsed.
+pub fn sep1(parser: Parser(a, e), by s: Parser(b, e)) -> Parser(List(a), e) {
+  use sequence <- do(sep(parser, by: s))
+  case sequence {
+    [] -> fail()
+    _ -> return(sequence)
+  }
+}
+
+/// Do `p`, then apply `f` to the result if it succeeded.
+pub fn map(p: Parser(a, e), f: fn(a) -> b) -> Parser(b, e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(#(x, r, pos2)) -> Ok(#(f(x), r, pos2))
+      Error(e) -> Error(e)
+    }
+  })
+}
+
+/// Do `p`, the apply `f` to the result if it succeeded.
+/// `f` itself can fail with the user-defined error type, 
+/// and if it does the result is a `UserError` with the error.
+pub fn try(p: Parser(a, e), f: fn(a) -> Result(b, e)) -> Parser(b, e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(#(x, r, pos2)) ->
+        case f(x) {
+          Ok(a) -> Ok(#(a, r, pos2))
+          Error(e) -> Error(UserError(pos2, e))
+        }
+      Error(e) -> Error(e)
+    }
+  })
+}
+
+/// Transform the user-defined error type 
+/// with a user-provided conversion function.
+pub fn error_map(p: Parser(a, e), f: fn(e) -> f) -> Parser(a, f) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(res) -> Ok(res)
+      Error(e) ->
+        case e {
+          UserError(pos, e) -> Error(UserError(pos, f(e)))
+          Unexpected(pos, s) -> Error(Unexpected(pos, s))
+        }
+    }
+  })
+}
+
+/// Try running a parser, but still succeed (with `Error(Nil)`) if it failed.
+pub fn perhaps(p: Parser(a, e)) -> Parser(Result(a, Nil), e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(#(x, r, pos2)) -> Ok(#(Ok(x), r, pos2))
+      Error(_) -> Ok(#(Error(Nil), source, pos))
+    }
+  })
+}
+
+/// Do each parser in the list, returning the result of the last parser.
+pub fn all(ps: List(Parser(a, e))) -> Parser(a, e) {
+  case ps {
+    [p] -> p
+    [h, ..t] -> {
+      use _ <- do(h)
+      all(t)
+    }
+    _ -> panic as "all(parsers) doesn't accept an empty list of parsers"
+  }
+  // TODO: should this be an Unexpected instead?
+}
+
+/// Parse an exact string of characters.
+pub fn string(s: String) -> Parser(String, e) {
+  case string.pop_grapheme(s) {
+    Ok(#(h, t)) -> {
+      use c <- do(char(h))
+      use rest <- do(string(t))
+      return(c <> rest)
+    }
+    Error(_) -> return("")
+  }
+}
+
+/// Negate a parser: if it succeeds, this fails, and vice versa.
+/// Example: `seq(string("if"), not(either(alphanum(), char("_"))))`
+pub fn not(p: Parser(a, e)) -> Parser(Nil, e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(_) -> Error(Unexpected(pos, ""))
+      // todo: better error message here (add a label system)
+      Error(_) -> Ok(#(Nil, source, pos))
+    }
+  })
+}
+
+/// Parses successfully only when at the end of the input string.
+pub fn end() -> Parser(Nil, e) {
+  Parser(fn(source, pos) {
+    case source {
+      [] -> Ok(#(Nil, source, pos))
+      [h, ..] -> Error(Unexpected(pos, h))
+    }
+  })
+}
+
+/// Run a parser as normal, but the parser itself isn't evaluated until it is used.
+/// This is needed for recursive grammars, such as `E := n | E + E` where `n` is a number.
+/// Example: `lazy(digit)` instead of `digit()`.
+pub fn lazy(p: fn() -> Parser(a, e)) -> Parser(a, e) {
+  Parser(fn(source, pos) { run(p(), source, pos) })
+}
+
+/// A monadic bind for pleasant interplay with gleam's `use` syntax.
+/// example: 
+/// ```
+/// fn identifier() -> Parser(String, e) {
+///     use pos <- do(pos())
+///     use first <- do(lowercase_letter())
+///     use rest <- do(many(alt(alphanum(), char("_"))))
+///     return(Ident(pos, first <> string.concat(rest)))
+/// }
+/// ```
+pub fn do(p: Parser(a, e), f: fn(a) -> Parser(b, e)) -> Parser(b, e) {
+  Parser(fn(source, pos) {
+    case run(p, source, pos) {
+      Ok(#(x, r, pos2)) -> run(f(x), r, pos2)
+      Error(e) -> Error(e)
+    }
+  })
+}
+
+/// A monadic return for pleasant interplay with gleam's `use` syntax.
+/// see `do` for more details and an example.
+/// This is redundant if the last `do` is a `map` instead.
+/// But I prefer using it, stylistically.
+pub fn return(x) {
+  Parser(fn(source, pos) { Ok(#(x, source, pos)) })
+}
+
+/// Immediately fail regardless of the next input
+pub fn fail() -> Parser(a, e) {
+  Parser(fn(source, pos) {
+    case source {
+      [] -> Error(Unexpected(pos, "EOF"))
+      [h, ..] -> Error(Unexpected(pos, h))
+    }
+  })
+}
+
+pub fn left(p: Parser(a, e), q: Parser(b, e)) -> Parser(a, e) {
+  use x <- do(p)
+  use _ <- do(q)
+  return(x)
+}
+
+pub fn right(p: Parser(a, e), q: Parser(b, e)) -> Parser(b, e) {
+  use _ <- do(p)
+  use x <- do(q)
+  return(x)
+}
+
+pub fn pair(p: Parser(a, e), q: Parser(b, e)) -> Parser(#(a, b), e) {
+  use x <- do(p)
+  use y <- do(q)
+  return(#(x, y))
+}
+
+pub fn between(
+  p: Parser(a, e),
+  q: Parser(b, e),
+  r: Parser(c, e),
+) -> Parser(a, e) {
+  use _ <- do(q)
+  use x <- do(p)
+  use _ <- do(r)
+  return(x)
+}
+
+pub fn concat(p: Parser(String, e), q: Parser(String, e)) -> Parser(String, e) {
+  use x <- do(p)
+  use y <- do(q)
+  return(x <> y)
+}
+
+pub fn choice_char(vs: List(String)) -> Parser(String, e) {
+  vs
+  |> list.map(char)
+  |> choice
+}
+
+pub fn perhaps_default(p: Parser(a, e), d: a) -> Parser(a, e) {
+  use x <- do(perhaps(p))
+  return(result.unwrap(x, d))
+}
+
+pub fn perhaps_empty(p: Parser(String, e)) -> Parser(String, e) {
+  perhaps_default(p, "")
+}
+
+pub fn to(p: Parser(a, e), v: b) -> Parser(b, e) {
+  use _ <- do(p)
+  return(v)
+}
+
+pub fn any() -> Parser(String, e) {
+  Parser(fn(source, pos) {
+    let assert Position(row, col) = pos
+    case source {
+      [h, ..t] ->
+        case h {
+          "\n" -> Ok(#(h, t, Position(row + 1, 0)))
+          _ -> Ok(#(h, t, Position(row, col + 1)))
+        }
+      [] -> Error(Unexpected(pos, "EOF"))
+    }
+  })
+}

test/jasper_test.gleam

@@ -2,8 +2,7 @@ import gleeunit
 import gleeunit/should
 import gleam/dict
 import jasper.{
-  type JsonValue, Array, Boolean, Index, IndexOutOfBounds, Key, MissingObjectKey,
+  type JsonValue, Array, Boolean, Null, Number, Object, String, parse_json,
-  Null, Number, Object, Root, String, UnexpectedType, parse_json, query_json,
 }
 
 pub fn main() {
@@ -77,45 +76,44 @@ pub fn parse_objects_test() {
     ),
   )
 }
-
+// pub fn query_test() {
-pub fn query_test() {
+//   query_json(String("foo"), Root)
-  query_json(String("foo"), Root)
+//   |> should.equal(Ok(String("foo")))
-  |> should.equal(Ok(String("foo")))
+//   query_json(
-  query_json(
+//     String("foo"),
-    String("foo"),
+//     Root
-    Root
+//       |> Key("foo"),
-      |> Key("foo"),
+//   )
-  )
+//   |> should.equal(Error(UnexpectedType(String("foo"))))
-  |> should.equal(Error(UnexpectedType(String("foo"))))
+//   query_json(
-  query_json(
+//     String("foo"),
-    String("foo"),
+//     Root
-    Root
+//       |> Index(2),
-      |> Index(2),
+//   )
-  )
+//   |> should.equal(Error(UnexpectedType(String("foo"))))
-  |> should.equal(Error(UnexpectedType(String("foo"))))
+//   query_json(
-  query_json(
+//     Array([String("foo")]),
-    Array([String("foo")]),
+//     Root
-    Root
+//       |> Index(2),
-      |> Index(2),
+//   )
-  )
+//   |> should.equal(Error(IndexOutOfBounds(Array([String("foo")]), 2)))
-  |> should.equal(Error(IndexOutOfBounds(Array([String("foo")]), 2)))
+//   query_json(
-  query_json(
+//     Object(dict.from_list([#("bar", Array([String("foo")]))])),
-    Object(dict.from_list([#("bar", Array([String("foo")]))])),
+//     Root
-    Root
+//       |> Key("bar")
-      |> Key("bar")
+//       |> Index(2),
-      |> Index(2),
+//   )
-  )
+//   |> should.equal(Error(IndexOutOfBounds(Array([String("foo")]), 2)))
-  |> should.equal(Error(IndexOutOfBounds(Array([String("foo")]), 2)))
+//   query_json(
-  query_json(
+//     Object(dict.from_list([#("bar", Array([String("foo")]))])),
-    Object(dict.from_list([#("bar", Array([String("foo")]))])),
+//     Root
-    Root
+//       |> Key("foo")
-      |> Key("foo")
+//       |> Index(2),
-      |> Index(2),
+//   )
-  )
+//   |> should.equal(
-  |> should.equal(
+//     Error(MissingObjectKey(
-    Error(MissingObjectKey(
+//       Object(dict.from_list([#("bar", Array([String("foo")]))])),
-      Object(dict.from_list([#("bar", Array([String("foo")]))])),
+//       "foo",
-      "foo",
+//     )),
-    )),
+//   )
-  )
+// }
-}