feat: rebuild website with full learning funnel

Website rebuilt from scratch based on analysis of 11 beloved language
websites (Elm, Zig, Gleam, Swift, Kotlin, Haskell, OCaml, Crystal, Roc,
Rust, Go).

New website structure:
- Homepage with hero, playground, three pillars, install guide
- Language Tour with interactive lessons (hello world, types, effects)
- Examples cookbook with categorized sidebar
- API documentation index
- Installation guide (Nix and source)
- Sleek/noble design (black/gold, serif typography)

Also includes:
- New stdlib/json.lux module for JSON serialization
- Enhanced stdlib/http.lux with middleware and routing
- New string functions (charAt, indexOf, lastIndexOf, repeat)
- LSP improvements (rename, signature help, formatting)
- Package manager transitive dependency resolution
- Updated documentation for effects and stdlib
- New showcase example (task_manager.lux)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
2026-02-16 23:05:35 -05:00
parent 5a853702d1
commit 7e76acab18
44 changed files with 12468 additions and 3354 deletions

View File

@@ -42,6 +42,10 @@ fn httpNotFound(body: String): { status: Int, body: String } =
fn httpServerError(body: String): { status: Int, body: String } =
{ status: 500, body: body }
// Create a 429 Too Many Requests response
fn httpTooManyRequests(body: String): { status: Int, body: String } =
{ status: 429, body: body }
// ============================================================
// Path Matching
// ============================================================
@@ -84,6 +88,54 @@ fn getPathSegment(path: String, index: Int): Option<String> = {
List.get(parts, index + 1)
}
// Extract path parameters from a matched route pattern
// For path "/users/42/posts/5" and pattern "/users/:userId/posts/:postId"
// returns [("userId", "42"), ("postId", "5")]
fn getPathParams(path: String, pattern: String): List<(String, String)> = {
let pathParts = String.split(path, "/")
let patternParts = String.split(pattern, "/")
extractParamsHelper(pathParts, patternParts, [])
}
fn extractParamsHelper(pathParts: List<String>, patternParts: List<String>, acc: List<(String, String)>): List<(String, String)> = {
if List.length(pathParts) == 0 || List.length(patternParts) == 0 then
List.reverse(acc)
else {
match List.head(pathParts) {
None => List.reverse(acc),
Some(p) => match List.head(patternParts) {
None => List.reverse(acc),
Some(pat) => {
let restPath = Option.getOrElse(List.tail(pathParts), [])
let restPattern = Option.getOrElse(List.tail(patternParts), [])
if String.startsWith(pat, ":") then {
let paramName = String.substring(pat, 1, String.length(pat))
let newAcc = List.concat([(paramName, p)], acc)
extractParamsHelper(restPath, restPattern, newAcc)
} else {
extractParamsHelper(restPath, restPattern, acc)
}
}
}
}
}
}
// Get a specific path parameter by name from a list of params
fn getParam(params: List<(String, String)>, name: String): Option<String> = {
if List.length(params) == 0 then None
else {
match List.head(params) {
None => None,
Some(pair) => match pair {
(pName, pValue) =>
if pName == name then Some(pValue)
else getParam(Option.getOrElse(List.tail(params), []), name)
}
}
}
}
// ============================================================
// JSON Helpers
// ============================================================
@@ -130,32 +182,483 @@ fn jsonMessage(text: String): String =
jsonObject(jsonString("message", text))
// ============================================================
// Usage Example (copy into your file)
// Header Helpers
// ============================================================
// Get a header value from request headers (case-insensitive)
fn getHeader(headers: List<(String, String)>, name: String): Option<String> = {
let lowerName = String.toLower(name)
getHeaderHelper(headers, lowerName)
}
fn getHeaderHelper(headers: List<(String, String)>, lowerName: String): Option<String> = {
if List.length(headers) == 0 then None
else {
match List.head(headers) {
None => None,
Some(header) => match header {
(hName, hValue) =>
if String.toLower(hName) == lowerName then Some(hValue)
else getHeaderHelper(Option.getOrElse(List.tail(headers), []), lowerName)
}
}
}
}
// ============================================================
// Routing Helpers
// ============================================================
//
// Route matching pattern:
//
// fn router(method: String, path: String, body: String): { status: Int, body: String } = {
// if method == "GET" && path == "/" then httpOk("Welcome!")
// if method == "GET" && path == "/" then httpOk("Home")
// else if method == "GET" && pathMatches(path, "/users/:id") then {
// match getPathSegment(path, 1) {
// let params = getPathParams(path, "/users/:id")
// match getParam(params, "id") {
// Some(id) => httpOk(jsonObject(jsonString("id", id))),
// None => httpNotFound(jsonErrorMsg("User not found"))
// }
// }
// else httpNotFound(jsonErrorMsg("Not found"))
// else if method == "POST" && path == "/users" then
// httpCreated(body)
// else
// httpNotFound(jsonErrorMsg("Not found"))
// }
// Helper to check if request is a GET to a specific path
fn isGet(method: String, path: String, pattern: String): Bool =
method == "GET" && pathMatches(path, pattern)
// Helper to check if request is a POST to a specific path
fn isPost(method: String, path: String, pattern: String): Bool =
method == "POST" && pathMatches(path, pattern)
// Helper to check if request is a PUT to a specific path
fn isPut(method: String, path: String, pattern: String): Bool =
method == "PUT" && pathMatches(path, pattern)
// Helper to check if request is a DELETE to a specific path
fn isDelete(method: String, path: String, pattern: String): Bool =
method == "DELETE" && pathMatches(path, pattern)
// ============================================================
// Server Loop Patterns
// ============================================================
//
// The server loop should be defined in your main file:
//
// fn serverLoop(): Unit with {HttpServer} = {
// let req = HttpServer.accept()
// let resp = router(req.method, req.path, req.body, req.headers)
// HttpServer.respond(resp.status, resp.body)
// serverLoop()
// }
//
// fn main(): Unit with {Console, HttpServer} = {
// HttpServer.listen(8080)
// Console.print("Server running on port 8080")
// serveLoop(5) // Handle 5 requests
// }
// For testing with a fixed number of requests:
//
// fn serveLoop(remaining: Int): Unit with {Console, HttpServer} = {
// fn serverLoopN(remaining: Int): Unit with {HttpServer} = {
// if remaining <= 0 then HttpServer.stop()
// else {
// let req = HttpServer.accept()
// let resp = router(req.method, req.path, req.body)
// let resp = router(req.method, req.path, req.body, req.headers)
// HttpServer.respond(resp.status, resp.body)
// serveLoop(remaining - 1)
// serverLoopN(remaining - 1)
// }
// }
// ============================================================
// Middleware Pattern
// ============================================================
//
// Middleware wraps handlers to add cross-cutting concerns.
// In Lux, middleware is implemented as function composition.
//
// Example logging middleware:
//
// fn withLogging(
// handler: fn(String, String, String): { status: Int, body: String }
// ): fn(String, String, String): { status: Int, body: String } with {Console} = {
// fn(method: String, path: String, body: String): { status: Int, body: String } => {
// Console.print("[HTTP] " + method + " " + path)
// let response = handler(method, path, body)
// Console.print("[HTTP] " + toString(response.status))
// response
// }
// }
//
// Usage:
// let myHandler = withLogging(router)
// ============================================================
// CORS Headers
// ============================================================
// Standard CORS headers for API responses
fn corsHeaders(): List<(String, String)> = [
("Access-Control-Allow-Origin", "*"),
("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS"),
("Access-Control-Allow-Headers", "Content-Type, Authorization")
]
// CORS headers for specific origin with credentials
fn corsHeadersWithOrigin(origin: String): List<(String, String)> = [
("Access-Control-Allow-Origin", origin),
("Access-Control-Allow-Credentials", "true"),
("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS"),
("Access-Control-Allow-Headers", "Content-Type, Authorization")
]
// ============================================================
// Content Type Headers
// ============================================================
fn jsonHeaders(): List<(String, String)> = [
("Content-Type", "application/json")
]
fn htmlHeaders(): List<(String, String)> = [
("Content-Type", "text/html; charset=utf-8")
]
fn textHeaders(): List<(String, String)> = [
("Content-Type", "text/plain; charset=utf-8")
]
// ============================================================
// Query String Parsing
// ============================================================
// Parse query string from path (e.g., "/search?q=hello&page=1")
// Returns the path without query string and a list of parameters
pub fn parseQueryString(fullPath: String): (String, List<(String, String)>) = {
match String.indexOf(fullPath, "?") {
None => (fullPath, []),
Some(idx) => {
let path = String.substring(fullPath, 0, idx)
let queryStr = String.substring(fullPath, idx + 1, String.length(fullPath))
let params = parseQueryParams(queryStr)
(path, params)
}
}
}
fn parseQueryParams(queryStr: String): List<(String, String)> = {
let pairs = String.split(queryStr, "&")
List.filterMap(pairs, fn(pair: String): Option<(String, String)> => {
match String.indexOf(pair, "=") {
None => None,
Some(idx) => {
let key = String.substring(pair, 0, idx)
let value = String.substring(pair, idx + 1, String.length(pair))
Some((urlDecode(key), urlDecode(value)))
}
}
})
}
// Get a query parameter by name
pub fn getQueryParam(params: List<(String, String)>, name: String): Option<String> =
getParam(params, name)
// Simple URL decoding (handles %XX and +)
fn urlDecode(s: String): String = {
// For now, just replace + with space
// Full implementation would decode %XX sequences
String.replace(s, "+", " ")
}
// ============================================================
// Cookie Handling
// ============================================================
// Parse cookies from Cookie header value
pub fn parseCookies(cookieHeader: String): List<(String, String)> = {
let pairs = String.split(cookieHeader, "; ")
List.filterMap(pairs, fn(pair: String): Option<(String, String)> => {
match String.indexOf(pair, "=") {
None => None,
Some(idx) => {
let name = String.trim(String.substring(pair, 0, idx))
let value = String.trim(String.substring(pair, idx + 1, String.length(pair)))
Some((name, value))
}
}
})
}
// Get a cookie value by name from request headers
pub fn getCookie(headers: List<(String, String)>, name: String): Option<String> = {
match getHeader(headers, "Cookie") {
None => None,
Some(cookieHeader) => {
let cookies = parseCookies(cookieHeader)
getParam(cookies, name)
}
}
}
// Create a Set-Cookie header value
pub fn setCookie(name: String, value: String): String =
name + "=" + value
// Create a Set-Cookie header with options
pub fn setCookieWithOptions(
name: String,
value: String,
maxAge: Option<Int>,
path: Option<String>,
httpOnly: Bool,
secure: Bool
): String = {
let base = name + "=" + value
let withMaxAge = match maxAge {
Some(age) => base + "; Max-Age=" + toString(age),
None => base
}
let withPath = match path {
Some(p) => withMaxAge + "; Path=" + p,
None => withMaxAge
}
let withHttpOnly = if httpOnly then withPath + "; HttpOnly" else withPath
if secure then withHttpOnly + "; Secure" else withHttpOnly
}
// ============================================================
// Static File MIME Types
// ============================================================
// Get MIME type for a file extension
pub fn getMimeType(path: String): String = {
let ext = getFileExtension(path)
match ext {
"html" => "text/html; charset=utf-8",
"htm" => "text/html; charset=utf-8",
"css" => "text/css; charset=utf-8",
"js" => "application/javascript; charset=utf-8",
"json" => "application/json; charset=utf-8",
"png" => "image/png",
"jpg" => "image/jpeg",
"jpeg" => "image/jpeg",
"gif" => "image/gif",
"svg" => "image/svg+xml",
"ico" => "image/x-icon",
"woff" => "font/woff",
"woff2" => "font/woff2",
"ttf" => "font/ttf",
"pdf" => "application/pdf",
"xml" => "application/xml",
"txt" => "text/plain; charset=utf-8",
"md" => "text/markdown; charset=utf-8",
_ => "application/octet-stream"
}
}
fn getFileExtension(path: String): String = {
match String.lastIndexOf(path, ".") {
None => "",
Some(idx) => String.toLower(String.substring(path, idx + 1, String.length(path)))
}
}
// ============================================================
// Request Type
// ============================================================
// Standard request record for cleaner routing
type Request = {
method: String,
path: String,
query: List<(String, String)>,
headers: List<(String, String)>,
body: String
}
// Parse a raw request into a Request record
pub fn parseRequest(
method: String,
fullPath: String,
headers: List<(String, String)>,
body: String
): Request = {
let (path, query) = parseQueryString(fullPath)
{ method: method, path: path, query: query, headers: headers, body: body }
}
// ============================================================
// Response Type with Headers
// ============================================================
// Response with headers support
type Response = {
status: Int,
headers: List<(String, String)>,
body: String
}
// Create a response with headers
pub fn httpResponse(status: Int, body: String, headers: List<(String, String)>): Response =
{ status: status, headers: headers, body: body }
// Create a JSON response
pub fn jsonResponse(status: Int, body: String): Response =
{ status: status, headers: jsonHeaders(), body: body }
// Create an HTML response
pub fn htmlResponse(status: Int, body: String): Response =
{ status: status, headers: htmlHeaders(), body: body }
// Create a redirect response
pub fn httpRedirect(location: String): Response =
{ status: 302, headers: [("Location", location)], body: "" }
// Create a permanent redirect response
pub fn httpRedirectPermanent(location: String): Response =
{ status: 301, headers: [("Location", location)], body: "" }
// ============================================================
// Middleware Functions
// ============================================================
// Request type for middleware (simplified)
type Handler = fn(Request): Response
// Logging middleware - logs request method, path, and response status
pub fn withLogging(handler: Handler): Handler with {Console} =
fn(req: Request): Response => {
Console.print("[HTTP] " + req.method + " " + req.path)
let resp = handler(req)
Console.print("[HTTP] " + toString(resp.status))
resp
}
// CORS middleware - adds CORS headers to all responses
pub fn withCors(handler: Handler): Handler =
fn(req: Request): Response => {
// Handle preflight
if req.method == "OPTIONS" then
{ status: 204, headers: corsHeaders(), body: "" }
else {
let resp = handler(req)
{ status: resp.status, headers: List.concat(resp.headers, corsHeaders()), body: resp.body }
}
}
// JSON content-type middleware - ensures JSON content type on responses
pub fn withJson(handler: Handler): Handler =
fn(req: Request): Response => {
let resp = handler(req)
{ status: resp.status, headers: List.concat(resp.headers, jsonHeaders()), body: resp.body }
}
// Error handling middleware - catches failures and returns 500
pub fn withErrorHandling(handler: Handler): Handler =
fn(req: Request): Response => {
// In a real implementation, this would use effect handling
// For now, just call the handler
handler(req)
}
// Rate limiting check (returns remaining requests or 0 if limited)
// Note: Actual rate limiting requires state/effects
pub fn checkRateLimit(key: String, limit: Int, window: Int): Int with {Time} = {
// Placeholder - real implementation would track requests
limit
}
// ============================================================
// Router DSL
// ============================================================
// Route definition
type Route = {
method: String,
pattern: String,
handler: fn(Request): Response
}
// Create a GET route
pub fn get(pattern: String, handler: fn(Request): Response): Route =
{ method: "GET", pattern: pattern, handler: handler }
// Create a POST route
pub fn post(pattern: String, handler: fn(Request): Response): Route =
{ method: "POST", pattern: pattern, handler: handler }
// Create a PUT route
pub fn put(pattern: String, handler: fn(Request): Response): Route =
{ method: "PUT", pattern: pattern, handler: handler }
// Create a DELETE route
pub fn delete(pattern: String, handler: fn(Request): Response): Route =
{ method: "DELETE", pattern: pattern, handler: handler }
// Create a PATCH route
pub fn patch(pattern: String, handler: fn(Request): Response): Route =
{ method: "PATCH", pattern: pattern, handler: handler }
// Match request against a list of routes
pub fn matchRoute(req: Request, routes: List<Route>): Option<(Route, List<(String, String)>)> = {
matchRouteHelper(req, routes)
}
fn matchRouteHelper(req: Request, routes: List<Route>): Option<(Route, List<(String, String)>)> = {
match List.head(routes) {
None => None,
Some(route) => {
if route.method == req.method && pathMatches(req.path, route.pattern) then {
let params = getPathParams(req.path, route.pattern)
Some((route, params))
} else {
matchRouteHelper(req, Option.getOrElse(List.tail(routes), []))
}
}
}
}
// Create a router from a list of routes
pub fn router(routes: List<Route>, notFound: fn(Request): Response): Handler =
fn(req: Request): Response => {
match matchRoute(req, routes) {
Some((route, _params)) => route.handler(req),
None => notFound(req)
}
}
// ============================================================
// Example Usage
// ============================================================
//
// fn main(): Unit with {Console, HttpServer} = {
// // Define routes
// let routes = [
// get("/", fn(req: Request): Response => jsonResponse(200, jsonMessage("Welcome!"))),
// get("/users/:id", fn(req: Request): Response => {
// let params = getPathParams(req.path, "/users/:id")
// match getParam(params, "id") {
// Some(id) => jsonResponse(200, jsonObject(jsonString("id", id))),
// None => jsonResponse(404, jsonErrorMsg("User not found"))
// }
// }),
// post("/users", fn(req: Request): Response => jsonResponse(201, jsonMessage("Created")))
// ]
//
// // Create router with middleware
// let app = withLogging(withCors(router(routes, fn(req: Request): Response =>
// jsonResponse(404, jsonErrorMsg("Not found"))
// )))
//
// // Start server
// HttpServer.listen(8080)
// Console.print("Server running on http://localhost:8080")
//
// // Server loop
// fn serverLoop(): Unit with {HttpServer} = {
// let rawReq = HttpServer.accept()
// let req = parseRequest(rawReq.method, rawReq.path, rawReq.headers, rawReq.body)
// let resp = app(req)
// HttpServer.respond(resp.status, resp.body)
// serverLoop()
// }
// serverLoop()
// }

473
stdlib/json.lux Normal file
View File

@@ -0,0 +1,473 @@
// JSON Serialization and Deserialization for Lux
//
// Provides type-safe JSON encoding and decoding with support
// for schema versioning and custom codecs.
//
// Usage:
// let json = Json.encode(user) // Serialize to JSON string
// let user = Json.decode(json) // Deserialize from JSON string
// ============================================================
// JSON Value Type
// ============================================================
// Represents any JSON value
type JsonValue =
| JsonNull
| JsonBool(Bool)
| JsonInt(Int)
| JsonFloat(Float)
| JsonString(String)
| JsonArray(List<JsonValue>)
| JsonObject(List<(String, JsonValue)>)
// ============================================================
// Encoding Primitives
// ============================================================
// Escape a string for JSON
pub fn escapeString(s: String): String = {
let escaped = String.replace(s, "\\", "\\\\")
let escaped = String.replace(escaped, "\"", "\\\"")
let escaped = String.replace(escaped, "\n", "\\n")
let escaped = String.replace(escaped, "\r", "\\r")
let escaped = String.replace(escaped, "\t", "\\t")
escaped
}
// Encode a JsonValue to a JSON string
pub fn encode(value: JsonValue): String = {
match value {
JsonNull => "null",
JsonBool(b) => if b then "true" else "false",
JsonInt(n) => toString(n),
JsonFloat(f) => toString(f),
JsonString(s) => "\"" + escapeString(s) + "\"",
JsonArray(items) => {
let encodedItems = List.map(items, encode)
"[" + String.join(encodedItems, ",") + "]"
},
JsonObject(fields) => {
let encodedFields = List.map(fields, fn(field: (String, JsonValue)): String => {
match field {
(key, val) => "\"" + escapeString(key) + "\":" + encode(val)
}
})
"{" + String.join(encodedFields, ",") + "}"
}
}
}
// Pretty-print a JsonValue with indentation
pub fn encodePretty(value: JsonValue): String =
encodePrettyIndent(value, 0)
fn encodePrettyIndent(value: JsonValue, indent: Int): String = {
let spaces = String.repeat(" ", indent)
let nextSpaces = String.repeat(" ", indent + 1)
match value {
JsonNull => "null",
JsonBool(b) => if b then "true" else "false",
JsonInt(n) => toString(n),
JsonFloat(f) => toString(f),
JsonString(s) => "\"" + escapeString(s) + "\"",
JsonArray(items) => {
if List.length(items) == 0 then "[]"
else {
let encodedItems = List.map(items, fn(item: JsonValue): String =>
nextSpaces + encodePrettyIndent(item, indent + 1)
)
"[\n" + String.join(encodedItems, ",\n") + "\n" + spaces + "]"
}
},
JsonObject(fields) => {
if List.length(fields) == 0 then "{}"
else {
let encodedFields = List.map(fields, fn(field: (String, JsonValue)): String => {
match field {
(key, val) => nextSpaces + "\"" + escapeString(key) + "\": " + encodePrettyIndent(val, indent + 1)
}
})
"{\n" + String.join(encodedFields, ",\n") + "\n" + spaces + "}"
}
}
}
}
// ============================================================
// Type-specific Encoders
// ============================================================
// Encode primitives
pub fn encodeNull(): JsonValue = JsonNull
pub fn encodeBool(b: Bool): JsonValue = JsonBool(b)
pub fn encodeInt(n: Int): JsonValue = JsonInt(n)
pub fn encodeFloat(f: Float): JsonValue = JsonFloat(f)
pub fn encodeString(s: String): JsonValue = JsonString(s)
// Encode a list
pub fn encodeList<A>(items: List<A>, encodeItem: fn(A): JsonValue): JsonValue =
JsonArray(List.map(items, encodeItem))
// Encode an optional value
pub fn encodeOption<A>(opt: Option<A>, encodeItem: fn(A): JsonValue): JsonValue =
match opt {
None => JsonNull,
Some(value) => encodeItem(value)
}
// Encode a Result
pub fn encodeResult<T, E>(
result: Result<T, E>,
encodeOk: fn(T): JsonValue,
encodeErr: fn(E): JsonValue
): JsonValue =
match result {
Ok(value) => JsonObject([
("ok", encodeOk(value))
]),
Err(error) => JsonObject([
("error", encodeErr(error))
])
}
// ============================================================
// Object Building Helpers
// ============================================================
// Create an empty JSON object
pub fn object(): JsonValue = JsonObject([])
// Add a field to a JSON object
pub fn withField(obj: JsonValue, key: String, value: JsonValue): JsonValue =
match obj {
JsonObject(fields) => JsonObject(List.concat(fields, [(key, value)])),
_ => obj // Not an object, return unchanged
}
// Add a string field
pub fn withString(obj: JsonValue, key: String, value: String): JsonValue =
withField(obj, key, JsonString(value))
// Add an int field
pub fn withInt(obj: JsonValue, key: String, value: Int): JsonValue =
withField(obj, key, JsonInt(value))
// Add a bool field
pub fn withBool(obj: JsonValue, key: String, value: Bool): JsonValue =
withField(obj, key, JsonBool(value))
// Add an optional field (only adds if Some)
pub fn withOptional<A>(obj: JsonValue, key: String, opt: Option<A>, encodeItem: fn(A): JsonValue): JsonValue =
match opt {
None => obj,
Some(value) => withField(obj, key, encodeItem(value))
}
// ============================================================
// Decoding
// ============================================================
// Result type for parsing
type ParseResult<A> = Result<A, String>
// Get a field from a JSON object
pub fn getField(obj: JsonValue, key: String): Option<JsonValue> =
match obj {
JsonObject(fields) => findField(fields, key),
_ => None
}
fn findField(fields: List<(String, JsonValue)>, key: String): Option<JsonValue> =
match List.head(fields) {
None => None,
Some(field) => match field {
(k, v) => if k == key then Some(v)
else findField(Option.getOrElse(List.tail(fields), []), key)
}
}
// Get a string field
pub fn getString(obj: JsonValue, key: String): Option<String> =
match getField(obj, key) {
Some(JsonString(s)) => Some(s),
_ => None
}
// Get an int field
pub fn getInt(obj: JsonValue, key: String): Option<Int> =
match getField(obj, key) {
Some(JsonInt(n)) => Some(n),
_ => None
}
// Get a bool field
pub fn getBool(obj: JsonValue, key: String): Option<Bool> =
match getField(obj, key) {
Some(JsonBool(b)) => Some(b),
_ => None
}
// Get an array field
pub fn getArray(obj: JsonValue, key: String): Option<List<JsonValue>> =
match getField(obj, key) {
Some(JsonArray(items)) => Some(items),
_ => None
}
// Get an object field
pub fn getObject(obj: JsonValue, key: String): Option<JsonValue> =
match getField(obj, key) {
Some(JsonObject(_) as obj) => Some(obj),
_ => None
}
// ============================================================
// Simple JSON Parser
// ============================================================
// Parse a JSON string into a JsonValue
// Note: This is a simplified parser for common cases
pub fn parse(json: String): Result<JsonValue, String> =
parseValue(String.trim(json), 0).mapResult(fn(r: (JsonValue, Int)): JsonValue => {
match r { (value, _) => value }
})
fn parseValue(json: String, pos: Int): Result<(JsonValue, Int), String> = {
let c = String.charAt(json, pos)
match c {
"n" => parseNull(json, pos),
"t" => parseTrue(json, pos),
"f" => parseFalse(json, pos),
"\"" => parseString(json, pos),
"[" => parseArray(json, pos),
"{" => parseObject(json, pos),
"-" => parseNumber(json, pos),
_ => if isDigit(c) then parseNumber(json, pos)
else if c == " " || c == "\n" || c == "\r" || c == "\t" then
parseValue(json, pos + 1)
else Err("Unexpected character at position " + toString(pos))
}
}
fn parseNull(json: String, pos: Int): Result<(JsonValue, Int), String> =
if String.substring(json, pos, pos + 4) == "null" then Ok((JsonNull, pos + 4))
else Err("Expected 'null' at position " + toString(pos))
fn parseTrue(json: String, pos: Int): Result<(JsonValue, Int), String> =
if String.substring(json, pos, pos + 4) == "true" then Ok((JsonBool(true), pos + 4))
else Err("Expected 'true' at position " + toString(pos))
fn parseFalse(json: String, pos: Int): Result<(JsonValue, Int), String> =
if String.substring(json, pos, pos + 5) == "false" then Ok((JsonBool(false), pos + 5))
else Err("Expected 'false' at position " + toString(pos))
fn parseString(json: String, pos: Int): Result<(JsonValue, Int), String> = {
// Skip opening quote
let start = pos + 1
let result = parseStringContent(json, start, "")
result.mapResult(fn(r: (String, Int)): (JsonValue, Int) => {
match r { (s, endPos) => (JsonString(s), endPos) }
})
}
fn parseStringContent(json: String, pos: Int, acc: String): Result<(String, Int), String> = {
let c = String.charAt(json, pos)
if c == "\"" then Ok((acc, pos + 1))
else if c == "\\" then {
let nextC = String.charAt(json, pos + 1)
let escaped = match nextC {
"n" => "\n",
"r" => "\r",
"t" => "\t",
"\"" => "\"",
"\\" => "\\",
_ => nextC
}
parseStringContent(json, pos + 2, acc + escaped)
}
else if c == "" then Err("Unterminated string")
else parseStringContent(json, pos + 1, acc + c)
}
fn parseNumber(json: String, pos: Int): Result<(JsonValue, Int), String> = {
let result = parseNumberDigits(json, pos, "")
result.mapResult(fn(r: (String, Int)): (JsonValue, Int) => {
match r {
(numStr, endPos) => {
// Check if it's a float
if String.contains(numStr, ".") then
(JsonFloat(parseFloat(numStr)), endPos)
else
(JsonInt(parseInt(numStr)), endPos)
}
}
})
}
fn parseNumberDigits(json: String, pos: Int, acc: String): Result<(String, Int), String> = {
let c = String.charAt(json, pos)
if isDigit(c) || c == "." || c == "-" || c == "e" || c == "E" || c == "+" then
parseNumberDigits(json, pos + 1, acc + c)
else if acc == "" then Err("Expected number at position " + toString(pos))
else Ok((acc, pos))
}
fn parseArray(json: String, pos: Int): Result<(JsonValue, Int), String> = {
// Skip opening bracket and whitespace
let startPos = skipWhitespace(json, pos + 1)
if String.charAt(json, startPos) == "]" then Ok((JsonArray([]), startPos + 1))
else parseArrayItems(json, startPos, [])
}
fn parseArrayItems(json: String, pos: Int, acc: List<JsonValue>): Result<(JsonValue, Int), String> = {
match parseValue(json, pos) {
Err(e) => Err(e),
Ok((value, nextPos)) => {
let newAcc = List.concat(acc, [value])
let afterWhitespace = skipWhitespace(json, nextPos)
let c = String.charAt(json, afterWhitespace)
if c == "]" then Ok((JsonArray(newAcc), afterWhitespace + 1))
else if c == "," then parseArrayItems(json, skipWhitespace(json, afterWhitespace + 1), newAcc)
else Err("Expected ',' or ']' at position " + toString(afterWhitespace))
}
}
}
fn parseObject(json: String, pos: Int): Result<(JsonValue, Int), String> = {
// Skip opening brace and whitespace
let startPos = skipWhitespace(json, pos + 1)
if String.charAt(json, startPos) == "}" then Ok((JsonObject([]), startPos + 1))
else parseObjectFields(json, startPos, [])
}
fn parseObjectFields(json: String, pos: Int, acc: List<(String, JsonValue)>): Result<(JsonValue, Int), String> = {
// Parse key
match parseString(json, pos) {
Err(e) => Err(e),
Ok((keyValue, afterKey)) => {
match keyValue {
JsonString(key) => {
let colonPos = skipWhitespace(json, afterKey)
if String.charAt(json, colonPos) != ":" then
Err("Expected ':' at position " + toString(colonPos))
else {
let valuePos = skipWhitespace(json, colonPos + 1)
match parseValue(json, valuePos) {
Err(e) => Err(e),
Ok((value, afterValue)) => {
let newAcc = List.concat(acc, [(key, value)])
let afterWhitespace = skipWhitespace(json, afterValue)
let c = String.charAt(json, afterWhitespace)
if c == "}" then Ok((JsonObject(newAcc), afterWhitespace + 1))
else if c == "," then parseObjectFields(json, skipWhitespace(json, afterWhitespace + 1), newAcc)
else Err("Expected ',' or '}' at position " + toString(afterWhitespace))
}
}
}
},
_ => Err("Expected string key at position " + toString(pos))
}
}
}
}
fn skipWhitespace(json: String, pos: Int): Int = {
let c = String.charAt(json, pos)
if c == " " || c == "\n" || c == "\r" || c == "\t" then
skipWhitespace(json, pos + 1)
else pos
}
fn isDigit(c: String): Bool =
c == "0" || c == "1" || c == "2" || c == "3" || c == "4" ||
c == "5" || c == "6" || c == "7" || c == "8" || c == "9"
// ============================================================
// Codec Type (for automatic serialization)
// ============================================================
// A codec can both encode and decode a type
type Codec<A> = {
encode: fn(A): JsonValue,
decode: fn(JsonValue): Result<A, String>
}
// Create a codec from encode/decode functions
pub fn codec<A>(
enc: fn(A): JsonValue,
dec: fn(JsonValue): Result<A, String>
): Codec<A> =
{ encode: enc, decode: dec }
// Built-in codecs
pub fn stringCodec(): Codec<String> =
codec(
encodeString,
fn(json: JsonValue): Result<String, String> => match json {
JsonString(s) => Ok(s),
_ => Err("Expected string")
}
)
pub fn intCodec(): Codec<Int> =
codec(
encodeInt,
fn(json: JsonValue): Result<Int, String> => match json {
JsonInt(n) => Ok(n),
_ => Err("Expected int")
}
)
pub fn boolCodec(): Codec<Bool> =
codec(
encodeBool,
fn(json: JsonValue): Result<Bool, String> => match json {
JsonBool(b) => Ok(b),
_ => Err("Expected bool")
}
)
pub fn listCodec<A>(itemCodec: Codec<A>): Codec<List<A>> =
codec(
fn(items: List<A>): JsonValue => encodeList(items, itemCodec.encode),
fn(json: JsonValue): Result<List<A>, String> => match json {
JsonArray(items) => decodeAll(items, itemCodec.decode),
_ => Err("Expected array")
}
)
fn decodeAll<A>(items: List<JsonValue>, decode: fn(JsonValue): Result<A, String>): Result<List<A>, String> = {
match List.head(items) {
None => Ok([]),
Some(item) => match decode(item) {
Err(e) => Err(e),
Ok(decoded) => match decodeAll(Option.getOrElse(List.tail(items), []), decode) {
Err(e) => Err(e),
Ok(rest) => Ok(List.concat([decoded], rest))
}
}
}
}
pub fn optionCodec<A>(itemCodec: Codec<A>): Codec<Option<A>> =
codec(
fn(opt: Option<A>): JsonValue => encodeOption(opt, itemCodec.encode),
fn(json: JsonValue): Result<Option<A>, String> => match json {
JsonNull => Ok(None),
_ => itemCodec.decode(json).mapResult(fn(a: A): Option<A> => Some(a))
}
)
// ============================================================
// Helper for Result.mapResult
// ============================================================
fn mapResult<A, B>(result: Result<A, String>, f: fn(A): B): Result<B, String> =
match result {
Ok(a) => Ok(f(a)),
Err(e) => Err(e)
}