feat: add JSON parsing and manipulation support

Add comprehensive JSON support via the Json module: - Parse JSON strings with Json.parse() returning Result<Json, String> - Stringify with Json.stringify() and Json.prettyPrint() - Extract values with Json.get(), getIndex(), asString(), asInt(), etc. - Build JSON with constructors: Json.null(), bool(), int(), string(), array(), object() - Query with Json.isNull() and Json.keys() Includes example at examples/json.lux demonstrating building, parsing, and extracting JSON data with file I/O integration. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-02-13 16:22:35 -05:00
parent b0f6756411
commit ef9746c2fe
3 changed files with 580 additions and 0 deletions
--- a/examples/json.lux
+++ b/examples/json.lux
@@ -0,0 +1,112 @@
+// JSON example - demonstrates JSON parsing and manipulation
+//
+// This script parses JSON, extracts values, and builds new JSON structures
+
+fn main(): Unit with {Console, File} = {
+    Console.print("=== Lux JSON Example ===")
+    Console.print("")
+
+    // First, build some JSON programmatically
+    Console.print("=== Building JSON ===")
+    Console.print("")
+
+    let name = Json.string("Alice")
+    let age = Json.int(30)
+    let active = Json.bool(true)
+    let scores = Json.array([Json.int(95), Json.int(87), Json.int(92)])
+
+    let person = Json.object([("name", name), ("age", age), ("active", active), ("scores", scores)])
+
+    Console.print("Built JSON:")
+    let pretty = Json.prettyPrint(person)
+    Console.print(pretty)
+    Console.print("")
+
+    // Stringify to a compact string
+    let jsonStr = Json.stringify(person)
+    Console.print("Compact: " + jsonStr)
+    Console.print("")
+
+    // Write to file and read back to test parsing
+    File.write("/tmp/test.json", jsonStr)
+    Console.print("Written to /tmp/test.json")
+    Console.print("")
+
+    // Read and parse from file
+    Console.print("=== Parsing JSON ===")
+    Console.print("")
+    let content = File.read("/tmp/test.json")
+    Console.print("Read from file: " + content)
+    Console.print("")
+
+    match Json.parse(content) {
+        Ok(json) => {
+            Console.print("Parse succeeded!")
+            Console.print("")
+
+            // Get string field
+            Console.print("Extracting fields:")
+            match Json.get(json, "name") {
+                Some(nameJson) => match Json.asString(nameJson) {
+                    Some(n) => Console.print("  name: " + n),
+                    None => Console.print("  name: (not a string)")
+                },
+                None => Console.print("  name: (not found)")
+            }
+
+            // Get int field
+            match Json.get(json, "age") {
+                Some(ageJson) => match Json.asInt(ageJson) {
+                    Some(a) => Console.print("  age: " + toString(a)),
+                    None => Console.print("  age: (not an int)")
+                },
+                None => Console.print("  age: (not found)")
+            }
+
+            // Get bool field
+            match Json.get(json, "active") {
+                Some(activeJson) => match Json.asBool(activeJson) {
+                    Some(a) => Console.print("  active: " + toString(a)),
+                    None => Console.print("  active: (not a bool)")
+                },
+                None => Console.print("  active: (not found)")
+            }
+
+            // Get array field
+            match Json.get(json, "scores") {
+                Some(scoresJson) => match Json.asArray(scoresJson) {
+                    Some(arr) => {
+                        Console.print("  scores: " + toString(List.length(arr)) + " items")
+                        // Get first score
+                        match Json.getIndex(scoresJson, 0) {
+                            Some(firstJson) => match Json.asInt(firstJson) {
+                                Some(first) => Console.print("    first score: " + toString(first)),
+                                None => Console.print("    first score: (not an int)")
+                            },
+                            None => Console.print("    (no first element)")
+                        }
+                    },
+                    None => Console.print("  scores: (not an array)")
+                },
+                None => Console.print("  scores: (not found)")
+            }
+            Console.print("")
+
+            // Get the keys
+            Console.print("Object keys:")
+            match Json.keys(json) {
+                Some(ks) => Console.print("  " + String.join(ks, ", ")),
+                None => Console.print("  (not an object)")
+            }
+        },
+        Err(e) => Console.print("Parse error: " + e)
+    }
+
+    Console.print("")
+    Console.print("=== JSON Null Check ===")
+    let nullVal = Json.null()
+    Console.print("Is null value null? " + toString(Json.isNull(nullVal)))
+    Console.print("Is person null? " + toString(Json.isNull(person)))
+}
+
+let result = run main() with {}