Migrate from json to json-ng

CLAUDE.md

@@ -21,7 +21,7 @@ Uses `corral` for dependency management. `make` automatically runs `corral fetch
 - `github.com/ponylang/http.git` -- HTTP client
 - `github.com/ponylang/net_ssl.git` (via http) -- SSL/TLS
 - `github.com/kulibali/kiuatan.git` -- PEG parsing (for URI templates and Link headers)
-- `github.com/ponylang/json.git` -- JSON parsing
+- `github.com/ponylang/json-ng.git` -- JSON parsing (immutable, persistent collections)
 
 ## Source Layout
 
@@ -45,14 +45,15 @@ github_rest_api/
   search.pony              -- SearchIssues + SearchResults generic
   user.pony                -- User model
   license.pony             -- License model
+  json_nav_util.pony       -- JsonNavUtil (string_or_none for nullable JSON fields)
   paginated_list.pony      -- PaginatedList[A] with prev/next page navigation
   request/                 -- HTTP request infrastructure (temporary home, intended to be extracted to its own library)
     http.pony              -- Credentials, ResultReceiver, RequestFactory
     http_get.pony          -- JsonRequester (GET with JSON response)
     http_post.pony         -- HTTPPost (POST with JSON response)
     http_delete.pony       -- HTTPDelete (DELETE, expects 204)
     request_error.pony     -- RequestError (status, response_body, message)
-    json.pony              -- JsonConverter interface
+    json.pony              -- JsonConverter interface, JsonTypeString utility
     query_params.pony      -- QueryParams (URL query string builder with percent-encoding)
     _test.pony             -- QueryParams tests (example + property-based)
   simple_uri_template/     -- RFC 6570 path segment expansion (PEG-based; temporary home, intended to be extracted to its own library)

corral.json

@@ -15,8 +15,8 @@
       "version": "0.6.4"
     },
     {
-      "locator": "github.com/ponylang/json.git",
-      "version": "0.2.0"
+      "locator": "github.com/ponylang/json-ng.git",
+      "version": "0.1.0"
     }
   ],
   "info": {

github_rest_api/asset.pony

@@ -50,22 +50,20 @@ class val Asset
     browser_download_url = browser_download_url'
 
 primitive AssetJsonConverter is req.JsonConverter[Asset]
-  fun apply(json: JsonType val, creds: req.Credentials): Asset ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let id = JsonExtractor(obj("id")?).as_i64()?
-    let node_id = JsonExtractor(obj("node_id")?).as_string()?
-    let name = JsonExtractor(obj("name")?).as_string()?
-    let label = JsonExtractor(obj("label")?).as_string_or_none()?
-    let uploader = UserJsonConverter(obj("uploader")?, creds)?
-    let content_type = JsonExtractor(obj("content_type")?).as_string()?
-    let state = JsonExtractor(obj("state")?).as_string()?
-    let size = JsonExtractor(obj("size")?).as_i64()?
-    let download_count = JsonExtractor(obj("download_count")?).as_i64()?
-    let created_at = JsonExtractor(obj("created_at")?).as_string()?
-    let updated_at = JsonExtractor(obj("updated_at")?).as_string()?
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let browser_download_url =
-      JsonExtractor(obj("browser_download_url")?).as_string()?
+  fun apply(json: JsonNav, creds: req.Credentials): Asset ? =>
+    let id = json("id").as_i64()?
+    let node_id = json("node_id").as_string()?
+    let name = json("name").as_string()?
+    let label = JsonNavUtil.string_or_none(json("label"))?
+    let uploader = UserJsonConverter(json("uploader"), creds)?
+    let content_type = json("content_type").as_string()?
+    let state = json("state").as_string()?
+    let size = json("size").as_i64()?
+    let download_count = json("download_count").as_i64()?
+    let created_at = json("created_at").as_string()?
+    let updated_at = json("updated_at").as_string()?
+    let url = json("url").as_string()?
+    let browser_download_url = json("browser_download_url").as_string()?
 
     Asset(creds,
       id,

github_rest_api/commit.pony

@@ -67,20 +67,19 @@ primitive GetCommit
     p
 
 primitive CommitJsonConverter is req.JsonConverter[Commit]
-  fun apply(json: JsonType val, creds: req.Credentials): Commit ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let sha = JsonExtractor(obj("sha")?).as_string()?
+  fun apply(json: JsonNav, creds: req.Credentials): Commit ? =>
+    let sha = json("sha").as_string()?
 
     let files = recover trn Array[CommitFile] end
-    for f in JsonExtractor(obj("files")?).as_array()?.values() do
-      let file = CommitFileJsonConverter(f, creds)?
+    for f in json("files").as_array()?.values() do
+      let file = CommitFileJsonConverter(JsonNav(f), creds)?
       files.push(file)
     end
 
-    let git_commit = GitCommitJsonConverter(obj("commit")?, creds)?
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let html_url = JsonExtractor(obj("html_url")?).as_string()?
-    let comments_url = JsonExtractor(obj("comments_url")?).as_string()?
+    let git_commit = GitCommitJsonConverter(json("commit"), creds)?
+    let url = json("url").as_string()?
+    let html_url = json("html_url").as_string()?
+    let comments_url = json("comments_url").as_string()?
 
     Commit(creds,
       sha,

github_rest_api/commit_file.pony

@@ -19,12 +19,11 @@ class val CommitFile
     filename = filename'
 
 primitive CommitFileJsonConverter is req.JsonConverter[CommitFile]
-  fun apply(json: JsonType val,
+  fun apply(json: JsonNav,
     creds: req.Credentials): CommitFile ?
   =>
-    let obj = JsonExtractor(json).as_object()?
-    let sha = JsonExtractor(obj("sha")?).as_string()?
-    let status = JsonExtractor(obj("status")?).as_string()?
-    let filename = JsonExtractor(obj("filename")?).as_string()?
+    let sha = json("sha").as_string()?
+    let status = json("status").as_string()?
+    let filename = json("filename").as_string()?
 
     CommitFile(creds, sha, status, filename)

github_rest_api/git_commit.pony

@@ -21,11 +21,10 @@ class val GitCommit
     url = url'
 
 primitive GitCommitJsonConverter is req.JsonConverter[GitCommit]
-  fun apply(json: JsonType val, creds: req.Credentials): GitCommit ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let author = GitPersonJsonConverter(obj("author")?, creds)?
-    let committer = GitPersonJsonConverter(obj("committer")?, creds)?
-    let message = JsonExtractor(obj("message")?).as_string()?
-    let url = JsonExtractor(obj("url")?).as_string()?
+  fun apply(json: JsonNav, creds: req.Credentials): GitCommit ? =>
+    let author = GitPersonJsonConverter(json("author"), creds)?
+    let committer = GitPersonJsonConverter(json("committer"), creds)?
+    let message = json("message").as_string()?
+    let url = json("url").as_string()?
 
     GitCommit(creds, author, committer, message, url)

github_rest_api/git_person.pony

@@ -10,9 +10,8 @@ class val GitPerson
     email = email'
 
 primitive GitPersonJsonConverter is req.JsonConverter[GitPerson]
-  fun apply(json: JsonType val, creds: req.Credentials): GitPerson ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let name = JsonExtractor(obj("name")?).as_string()?
-    let email = JsonExtractor(obj("email")?).as_string()?
+  fun apply(json: JsonNav, creds: req.Credentials): GitPerson ? =>
+    let name = json("name").as_string()?
+    let email = json("email").as_string()?
 
     GitPerson(name, email)

github_rest_api/issue.pony

@@ -1,4 +1,3 @@
-use "collections"
 use "json"
 use "promises"
 use req = "request"
@@ -147,34 +146,33 @@ primitive GetRepositoryIssues
 
 
 primitive IssueJsonConverter is req.JsonConverter[Issue]
-  fun apply(json: JsonType val, creds: req.Credentials): Issue ? =>
-    let obj = JsonExtractor(json).as_object()?
-
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let respository_url = JsonExtractor(obj("repository_url")?).as_string()?
-    let labels_url = JsonExtractor(obj("labels_url")?).as_string()?
-    let comments_url = JsonExtractor(obj("comments_url")?).as_string()?
-    let events_url = JsonExtractor(obj("events_url")?).as_string()?
-    let html_url = JsonExtractor(obj("html_url")?).as_string()?
-
-    let number = JsonExtractor(obj("number")?).as_i64()?
-    let title = JsonExtractor(obj("title")?).as_string()?
-    let user = UserJsonConverter(obj("user")?, creds)?
-    let state = JsonExtractor(obj("state")?).as_string_or_none()?
-    let body = JsonExtractor(obj("body")?).as_string_or_none()?
+  fun apply(json: JsonNav, creds: req.Credentials): Issue ? =>
+    let url = json("url").as_string()?
+    let respository_url = json("repository_url").as_string()?
+    let labels_url = json("labels_url").as_string()?
+    let comments_url = json("comments_url").as_string()?
+    let events_url = json("events_url").as_string()?
+    let html_url = json("html_url").as_string()?
+
+    let number = json("number").as_i64()?
+    let title = json("title").as_string()?
+    let user = UserJsonConverter(json("user"), creds)?
+    let state = JsonNavUtil.string_or_none(json("state"))?
+    let body = JsonNavUtil.string_or_none(json("body"))?
 
     let labels = recover trn Array[Label] end
-    for i in JsonExtractor(obj("labels")?).as_array()?.values() do
-      let l = LabelJsonConverter(i, creds)?
+    for i in json("labels").as_array()?.values() do
+      let l = LabelJsonConverter(JsonNav(i), creds)?
       labels.push(l)
     end
 
-    let pull_request =
-      if obj.contains("pull_request") then
-        IssuePullRequestJsonConverter(obj("pull_request")?, creds)?
-      else
-        None
-      end
+    let pr_json = json("pull_request")
+    let pull_request = match pr_json.json()
+    | let _: JsonType =>
+      IssuePullRequestJsonConverter(pr_json, creds)?
+    else
+      None
+    end
 
     Issue(creds,
       url,

github_rest_api/issue_comment.pony

@@ -1,4 +1,3 @@
-use "collections"
 use "json"
 use "net"
 use "promises"
@@ -54,13 +53,11 @@ primitive CreateIssueComment
       p,
       IssueCommentJsonConverter)
 
-    let m: Map[String, JsonType] = m.create()
-    m.update("body", comment)
-    let json = JsonObject.from_map(m).string()
+    let json = JsonObject.update("body", comment).string()
 
     try
       req.HTTPPost(creds.auth)(url,
-        json,
+        consume json,
         r,
         creds.token)?
     else
@@ -115,25 +112,24 @@ primitive IssueCommentsURL
       end)
 
 primitive IssueCommentJsonConverter is req.JsonConverter[IssueComment]
-  fun apply(json: JsonType val,
+  fun apply(json: JsonNav,
     creds: req.Credentials): IssueComment ?
   =>
-    let obj = JsonExtractor(json).as_object()?
-    let body = JsonExtractor(obj("body")?).as_string()?
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let html_url = JsonExtractor(obj("html_url")?).as_string()?
-    let issue_url = JsonExtractor(obj("issue_url")?).as_string()?
+    let body = json("body").as_string()?
+    let url = json("url").as_string()?
+    let html_url = json("html_url").as_string()?
+    let issue_url = json("issue_url").as_string()?
 
     IssueComment(creds, body, url, html_url, issue_url)
 
 primitive IssueCommentsJsonConverter is req.JsonConverter[Array[IssueComment] val]
-  fun apply(json: JsonType val,
+  fun apply(json: JsonNav,
     creds: req.Credentials): Array[IssueComment] val ?
   =>
     let comments = recover trn Array[IssueComment] end
 
-    for i in JsonExtractor(json).as_array()?.values() do
-      let comment = IssueCommentJsonConverter(i, creds)?
+    for i in json.as_array()?.values() do
+      let comment = IssueCommentJsonConverter(JsonNav(i), creds)?
       comments.push(comment)
     end
 

github_rest_api/issue_pull_request.pony

@@ -29,12 +29,11 @@ class val IssuePullRequest
     merged_at = merged_at'
 
 primitive IssuePullRequestJsonConverter is req.JsonConverter[IssuePullRequest]
-  fun apply(json: JsonType val, creds: req.Credentials): IssuePullRequest ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let html_url = JsonExtractor(obj("html_url")?).as_string()?
-    let diff_url = JsonExtractor(obj("diff_url")?).as_string()?
-    let patch_url = JsonExtractor(obj("patch_url")?).as_string()?
-    let merged_at = JsonExtractor(obj("merged_at")?).as_string_or_none()?
+  fun apply(json: JsonNav, creds: req.Credentials): IssuePullRequest ? =>
+    let url = json("url").as_string()?
+    let html_url = json("html_url").as_string()?
+    let diff_url = json("diff_url").as_string()?
+    let patch_url = json("patch_url").as_string()?
+    let merged_at = JsonNavUtil.string_or_none(json("merged_at"))?
 
     IssuePullRequest(url, html_url, diff_url, patch_url, merged_at)

github_rest_api/json_nav_util.pony

@@ -0,0 +1,18 @@
+use "json"
+
+primitive JsonNavUtil
+  """
+  Utility for extracting optional string fields from JSON.
+
+  json-ng's JsonNav does not have an as_string_or_none() method. This
+  primitive provides equivalent functionality: given a JsonNav positioned on a
+  field, it returns the String value if present or None if the JSON value is
+  null. Raises an error if the navigation failed (key missing) or the value is
+  any other type.
+  """
+  fun string_or_none(json: JsonNav): (String | None) ? =>
+    match json.json()
+    | let s: String => s
+    | JsonNull => None
+    else error
+    end

github_rest_api/label.pony

@@ -1,4 +1,3 @@
-use "collections"
 use "json"
 use "promises"
 use req = "request"
@@ -69,19 +68,18 @@ primitive CreateLabel
       p,
       LabelJsonConverter)
 
-    let m: Map[String, JsonType] = m.create()
-    m.update("name", name)
+    var obj = JsonObject.update("name", name)
     match color
-    | let c: String => m.update("color", c)
+    | let c: String => obj = obj.update("color", c)
     end
     match description
-    | let d: String => m.update("description", d)
+    | let d: String => obj = obj.update("description", d)
     end
-    let json = JsonObject.from_map(m).string()
+    let json = obj.string()
 
     try
       req.HTTPPost(creds.auth)(url,
-        json,
+        consume json,
         r,
         creds.token)?
     else
@@ -133,15 +131,14 @@ primitive DeleteLabel
     p
 
 primitive LabelJsonConverter is req.JsonConverter[Label]
-  fun apply(json: JsonType val, creds: req.Credentials): Label ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let id = JsonExtractor(obj("id")?).as_i64()?
-    let node_id = JsonExtractor(obj("node_id")?).as_string()?
-    let url = JsonExtractor(obj("url")?).as_string()?
-    let name = JsonExtractor(obj("name")?).as_string()?
-    let color = JsonExtractor(obj("color")?).as_string()?
-    let default = JsonExtractor(obj("default")?).as_bool()?
-    let description = JsonExtractor(obj("description")?).as_string_or_none()?
+  fun apply(json: JsonNav, creds: req.Credentials): Label ? =>
+    let id = json("id").as_i64()?
+    let node_id = json("node_id").as_string()?
+    let url = json("url").as_string()?
+    let name = json("name").as_string()?
+    let color = json("color").as_string()?
+    let default = json("default").as_bool()?
+    let description = JsonNavUtil.string_or_none(json("description"))?
 
     Label(creds,
       id,

github_rest_api/license.pony

@@ -24,13 +24,12 @@ class val License
     url = url'
 
 primitive LicenseJsonConverter is req.JsonConverter[License]
-  fun apply(json: JsonType val, creds: req.Credentials): License ? =>
-    let obj = JsonExtractor(json).as_object()?
-    let node_id = JsonExtractor(obj("node_id")?).as_string()?
-    let name = JsonExtractor(obj("name")?).as_string()?
-    let key = JsonExtractor(obj("key")?).as_string()?
-    let spdx_id = JsonExtractor(obj("spdx_id")?).as_string()?
-    let url = JsonExtractor(obj("url")?).as_string()?
+  fun apply(json: JsonNav, creds: req.Credentials): License ? =>
+    let node_id = json("node_id").as_string()?
+    let name = json("name").as_string()?
+    let key = json("key").as_string()?
+    let spdx_id = json("spdx_id").as_string()?
+    let url = json("url").as_string()?
 
     License(creds,
       node_id,