feat: generate actual json in `encode function

BREAKING_CHANGE:
`encode_geojson` function was generating `dynamic.Dynamic` which is pretty useless from consumer standpoint. Now it is refactored to generate `Json` type which can be stringified with `json.to_string`.

Note: currently intentionally left encoding arbitrary `Feature` properties unimplemented.

Signed-off-by: Aleksei Gurianov <gurianov@gmail.com>

README.md

@@ -34,16 +34,27 @@ pub fn main() {
   case result {
     Ok(geojson) -> {
       // Successfully decoded GeoJSON
-      let encoded = gleojson.encode_geojson(geojson)
-      // encoded is now a Dynamic representation of the GeoJSON object
-      // You can use it for further processing or encoding back to JSON
     }
     Error(errors) -> {
       todo
       // Handle decoding errors
       // errors contains information about what went wrong during decoding
     }
   }
+
+  // Construct GeoJSON from types
+  let geojson = gleojson.GeoJSONFeatureCollection(
+    gleojson.FeatureCollection([
+      gleojson.Feature(
+        geometry: option.Some(gleojson.Point([1.0, 2.0])),
+        properties: option.None,
+        id: option.Some(gleojson.StringId("feature-id")),
+      ),
+    ]),
+  )
+
+  // Encode to JSON string
+  gleojson.encode_geojson(geojson) |> json.to_string
 }
 ```
 

birdie_snapshots/feature_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: feature_encode_decode
+---
+{"id":"feature-id","type":"Feature","geometry":{"type":"Point","coordinates":[1.0,2.0]},"properties":null}

birdie_snapshots/featurecollection_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: featurecollection_encode_decode
+---
+{"type":"FeatureCollection","features":[{"id":"feature-id","type":"Feature","geometry":{"type":"Point","coordinates":[1.0,2.0]},"properties":null}]}

birdie_snapshots/geometrycollection_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: geometrycollection_encode_decode
+---
+{"type":"GeometryCollection","geometries":[{"type":"Point","coordinates":[1.0,2.0]},{"type":"LineString","coordinates":[[3.0,4.0],[5.0,6.0]]}]}

birdie_snapshots/linestring_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: linestring_encode_decode
+---
+{"type":"LineString","coordinates":[[1.0,2.0],[3.0,4.0]]}

birdie_snapshots/multipoint_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: multipoint_encode_decode
+---
+{"type":"MultiPoint","coordinates":[[1.0,2.0],[3.0,4.0]]}

birdie_snapshots/multipolygon_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: multipolygon_encode_decode
+---
+{"type":"MultiPolygon","coordinates":[[[[1.0,2.0],[3.0,4.0],[5.0,6.0],[1.0,2.0]]],[[[7.0,8.0],[9.0,10.0],[11.0,12.0],[7.0,8.0]]]]}

birdie_snapshots/point_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: point_encode_decode
+---
+{"type":"Point","coordinates":[1.0,2.0]}

birdie_snapshots/polygon_encode_decode.accepted

@@ -0,0 +1,5 @@
+---
+version: 1.2.3
+title: polygon_encode_decode
+---
+{"type":"Polygon","coordinates":[[[1.0,2.0],[3.0,4.0],[5.0,6.0],[1.0,2.0]]]}

gleam.toml

@@ -8,7 +8,8 @@ links = [{ title = "RFC7946", href = "https://datatracker.ietf.org/doc/html/rfc7
 
 [dependencies]
 gleam_stdlib = ">= 0.34.0 and < 2.0.0"
+gleam_json = ">= 2.0.0 and < 3.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"
-gleam_json = ">= 2.0.0 and < 3.0.0"
+birdie = ">= 1.2.3 and < 2.0.0"

manifest.toml

@@ -2,12 +2,26 @@
 # You typically do not need to edit this file
 
 packages = [
+  { name = "argv", version = "1.0.2", build_tools = ["gleam"], requirements = [], otp_app = "argv", source = "hex", outer_checksum = "BA1FF0929525DEBA1CE67256E5ADF77A7CDDFE729E3E3F57A5BDCAA031DED09D" },
+  { name = "birdie", version = "1.2.3", build_tools = ["gleam"], requirements = ["argv", "edit_distance", "filepath", "glance", "gleam_community_ansi", "gleam_erlang", "gleam_stdlib", "justin", "rank", "simplifile", "trie_again"], otp_app = "birdie", source = "hex", outer_checksum = "AE1207210E9CC8F4170BCE3FB3C23932F314C352C3FD1BCEA44CF4BF8CF60F93" },
+  { name = "edit_distance", version = "2.0.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "edit_distance", source = "hex", outer_checksum = "A1E485C69A70210223E46E63985FA1008B8B2DDA9848B7897469171B29020C05" },
+  { name = "filepath", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "filepath", source = "hex", outer_checksum = "EFB6FF65C98B2A16378ABC3EE2B14124168C0CE5201553DE652E2644DCFDB594" },
+  { name = "glance", version = "0.11.0", build_tools = ["gleam"], requirements = ["gleam_stdlib", "glexer"], otp_app = "glance", source = "hex", outer_checksum = "8F3314D27773B7C3B9FB58D8C02C634290422CE531988C0394FA0DF8676B964D" },
+  { name = "gleam_community_ansi", version = "1.4.1", build_tools = ["gleam"], requirements = ["gleam_community_colour", "gleam_stdlib"], otp_app = "gleam_community_ansi", source = "hex", outer_checksum = "4CD513FC62523053E62ED7BAC2F36136EC17D6A8942728250A9A00A15E340E4B" },
+  { name = "gleam_community_colour", version = "1.3.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_community_colour", source = "hex", outer_checksum = "A49A5E3AE8B637A5ACBA80ECB9B1AFE89FD3D5351FF6410A42B84F666D40D7D5" },
+  { name = "gleam_erlang", version = "0.27.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_erlang", source = "hex", outer_checksum = "DE468F676D71B313C6C8C5334425CFCF827837333F8AB47B64D8A6D7AA40185D" },
   { name = "gleam_json", version = "2.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_json", source = "hex", outer_checksum = "CB10B0E7BF44282FB25162F1A24C1A025F6B93E777CCF238C4017E4EEF2CDE97" },
   { name = "gleam_stdlib", version = "0.40.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "86606B75A600BBD05E539EB59FABC6E307EEEA7B1E5865AFB6D980A93BCB2181" },
   { name = "gleeunit", version = "1.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "F7A7228925D3EE7D0813C922E062BFD6D7E9310F0BEE585D3A42F3307E3CFD13" },
+  { name = "glexer", version = "1.0.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "glexer", source = "hex", outer_checksum = "BD477AD657C2B637FEF75F2405FAEFFA533F277A74EF1A5E17B55B1178C228FB" },
+  { name = "justin", version = "1.0.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "justin", source = "hex", outer_checksum = "7FA0C6DB78640C6DC5FBFD59BF3456009F3F8B485BF6825E97E1EB44E9A1E2CD" },
+  { name = "rank", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "rank", source = "hex", outer_checksum = "5660E361F0E49CBB714CC57CC4C89C63415D8986F05B2DA0C719D5642FAD91C9" },
+  { name = "simplifile", version = "2.2.0", build_tools = ["gleam"], requirements = ["filepath", "gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "0DFABEF7DC7A9E2FF4BB27B108034E60C81BEBFCB7AB816B9E7E18ED4503ACD8" },
+  { name = "trie_again", version = "1.1.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "trie_again", source = "hex", outer_checksum = "5B19176F52B1BD98831B57FDC97BD1F88C8A403D6D8C63471407E78598E27184" },
 ]
 
 [requirements]
+birdie = { version = ">= 1.2.3 and < 2.0.0" }
 gleam_json = { version = ">= 2.0.0 and < 3.0.0" }
 gleam_stdlib = { version = ">= 0.34.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.0.0 and < 2.0.0" }

src/gleojson.gleam

@@ -16,7 +16,7 @@
 
 import gleam/dict
 import gleam/dynamic
-import gleam/list
+import gleam/json
 import gleam/option
 import gleam/result
 
@@ -64,90 +64,112 @@ pub type GeoJSON {
 
 // Encoding Functions
 
-/// Encodes a geometry into a dynamic value.
-fn encode_geometry(geometry: Geometry) -> dynamic.Dynamic {
+/// Encodes a geometry into a JSON object.
+fn encode_geometry(geometry: Geometry) -> json.Json {
   case geometry {
     Point(coordinates) -> {
-      dict.from_list([
-        #("type", dynamic.from("Point")),
-        #("coordinates", dynamic.from(coordinates)),
+      json.object([
+        #("type", json.string("Point")),
+        #("coordinates", json.array(coordinates, of: json.float)),
       ])
     }
     MultiPoint(multipoint) -> {
-      dict.from_list([
-        #("type", dynamic.from("MultiPoint")),
-        #("coordinates", dynamic.from(multipoint)),
+      json.object([
+        #("type", json.string("MultiPoint")),
+        #(
+          "coordinates",
+          json.array(multipoint, of: json.array(_, of: json.float)),
+        ),
       ])
     }
     LineString(linestring) -> {
-      dict.from_list([
-        #("type", dynamic.from("LineString")),
-        #("coordinates", dynamic.from(linestring)),
+      json.object([
+        #("type", json.string("LineString")),
+        #(
+          "coordinates",
+          json.array(linestring, of: json.array(_, of: json.float)),
+        ),
       ])
     }
     MultiLineString(multilinestring) -> {
-      dict.from_list([
-        #("type", dynamic.from("MultiLineString")),
-        #("coordinates", dynamic.from(multilinestring)),
+      json.object([
+        #("type", json.string("MultiLineString")),
+        #(
+          "coordinates",
+          json.array(multilinestring, of: json.array(_, of: json.array(
+            _,
+            of: json.float,
+          ))),
+        ),
       ])
     }
     Polygon(polygon) -> {
-      dict.from_list([
-        #("type", dynamic.from("Polygon")),
-        #("coordinates", dynamic.from(polygon)),
+      json.object([
+        #("type", json.string("Polygon")),
+        #(
+          "coordinates",
+          json.array(polygon, of: json.array(_, of: json.array(
+            _,
+            of: json.float,
+          ))),
+        ),
       ])
     }
     MultiPolygon(multipolygon) -> {
-      dict.from_list([
-        #("type", dynamic.from("MultiPolygon")),
-        #("coordinates", dynamic.from(multipolygon)),
+      json.object([
+        #("type", json.string("MultiPolygon")),
+        #(
+          "coordinates",
+          json.array(
+            multipolygon,
+            of: json.array(_, of: json.array(_, of: json.array(
+              _,
+              of: json.float,
+            ))),
+          ),
+        ),
       ])
     }
     GeometryCollection(collection) -> {
-      let geometries_dyn_list = list.map(collection, encode_geometry)
-      dict.from_list([
-        #("type", dynamic.from("GeometryCollection")),
-        #("geometries", dynamic.from(geometries_dyn_list)),
+      json.object([
+        #("type", json.string("GeometryCollection")),
+        #("geometries", json.array(collection, of: encode_geometry)),
       ])
     }
   }
-  |> dynamic.from
 }
 
-/// Encodes a feature into a dynamic value.
-fn encode_feature(feature: Feature) -> dynamic.Dynamic {
-  let Feature(geometry_opt, properties_opt, id_opt) = feature
-  let geometry_dyn = case geometry_opt {
+/// Encodes a feature into a JSON object.
+fn encode_feature(feature: Feature) -> json.Json {
+  let Feature(geometry_opt, _properties_opt, id_opt) = feature
+  let geometry_json = case geometry_opt {
     option.Some(geometry) -> encode_geometry(geometry)
-    option.None -> dynamic.from(Nil)
-  }
-  let properties_dyn = case properties_opt {
-    option.Some(props) -> dynamic.from(props)
-    option.None -> dynamic.from(Nil)
+    option.None -> json.null()
   }
-  let base_obj =
-    dict.from_list([
-      #("type", dynamic.from("Feature")),
-      #("geometry", geometry_dyn),
-      #("properties", properties_dyn),
-    ])
+  // let properties_json = case properties_opt {
+  //   option.Some(props) -> json.object(props)
+  //   option.None -> json.object([])
+  // }
+  let base_obj = [
+    #("type", json.string("Feature")),
+    #("geometry", geometry_json),
+    #("properties", json.null()),
+  ]
   case id_opt {
-    option.Some(StringId(id)) -> dict.insert(base_obj, "id", dynamic.from(id))
-    option.Some(NumberId(id)) -> dict.insert(base_obj, "id", dynamic.from(id))
+    option.Some(StringId(id)) -> [#("id", json.string(id)), ..base_obj]
+    option.Some(NumberId(id)) -> [#("id", json.float(id)), ..base_obj]
     option.None -> base_obj
   }
-  |> dynamic.from
+  |> json.object
 }
 
-/// Encodes a feature collection into a dynamic value.
-fn encode_featurecollection(collection: FeatureCollection) -> dynamic.Dynamic {
+/// Encodes a feature collection into a JSON object.
+fn encode_featurecollection(collection: FeatureCollection) -> json.Json {
   let FeatureCollection(features) = collection
-  let features_dyn_list = list.map(features, encode_feature)
-  dict.from_list([
-    #("type", dynamic.from("FeatureCollection")),
-    #("features", dynamic.from(features_dyn_list)),
+  json.object([
+    #("type", json.string("FeatureCollection")),
+    #("features", json.array(features, of: encode_feature)),
   ])
-  |> dynamic.from
 }
 
 /// Encodes a GeoJSON object into a dynamic value.
@@ -159,7 +181,7 @@ fn encode_featurecollection(collection: FeatureCollection) -> dynamic.Dynamic {
 /// let encoded = encode_geojson(point)
 /// // encoded will be a dynamic representation of the GeoJSON object
 /// ```
-pub fn encode_geojson(geojson: GeoJSON) -> dynamic.Dynamic {
+pub fn encode_geojson(geojson: GeoJSON) -> json.Json {
   case geojson {
     GeoJSONGeometry(geometry) -> encode_geometry(geometry)
     GeoJSONFeature(feature) -> encode_feature(feature)