Syntax research.

dev/syntax-research/syntax-doc.R

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+box::use(interface[interface, fun, generic])
+
+# Define an interface for a data structure
+PersonData <- interface(
+    name = "character",
+    age = "numeric",
+    email = "character",
+    scores = "data.frame"
+)
+
+# Implement the interface
+john_data <- PersonData(,
+    name = "John Doe",
+    age = 30,
+    email = "john@example.com",
+    scores = data.frame(subject = c("Math", "Science"), score = c(95, 88))
+)
+
+# Access data safely
+print(john_data$name)
+#> [1] "John Doe"
+
+print(john_data$scores)
+#>   subject score
+#> 1    Math    95
+#> 2 Science    88
+
+# This will raise an error, preventing silent issues
+try(john_data$age <- "thirty")
+#> Error in `$<-.validated_list`(`*tmp*`, age, value = "thirty") : 
+#>   Property 'age' does not match the expected type specification
+
+# Define a basic interface
+SimpleDataset <- interface(
+    id = "integer",
+    value = "numeric",
+    category = "factor"
+)
+
+# Implement the interface
+valid_data <- SimpleDataset(
+    id = 1L,
+    value = 10.5,
+    category = factor("A", levels = c("A", "B", "C"))
+)
+
+print(valid_data)
+#> Object implementing SimpleDataset interface:
+#>   id: 1 
+#>   value: 10.5 
+#>   category: 1 
+#> Validation on access: Enabled
+
+### Custom Validation Functions
+
+# Custom validation function
+is_valid_email <- function(x) {
+    grepl("^[^@\\s]+@[^@\\s]+\\.[^@\\s]+$", x)
+}
+
+# Interface with custom validation
+UserProfile <- interface(
+    username = "character",
+    email = is_valid_email,
+    age = function(x) is.numeric(x) && x >= 18
+)
+
+# Implement with valid data
+valid_user <- UserProfile(,
+    username = "john_doe",
+    email = "john@example.com",
+    age = 25
+)
+
+print(valid_user)
+#> Object implementing UserProfile interface:
+#>   username: john_doe 
+#>   email: john@example.com 
+#>   age: 25 
+#> Validation on access: Enabled
+
+# This will raise an error due to invalid email
+try(UserProfile(
+    username = "jane_doe",
+    email = "not_an_email",
+    age = 30
+))
+#> Error in validate_object(obj, interface) : 
+#>   Property 'email' does not match the expected type specification
+
+# nested interfaces
+Address <- interface(
+    street = "character",
+    city = "character",
+    postal_code = "character"
+)
+
+Employee <- interface(
+    name = "character",
+    position = "character",
+    address = Address
+)
+
+employee_data <- Employee(,
+    name = "Alice Johnson",
+    position = "Data Scientist",
+    address = Address(
+        street = "123 Tech Street",
+        city = "Data City",
+        postal_code = "12345"
+    )
+)
+
+print(employee_data$address$city)
+#> [1] "Data City"
+
+
+# Toggle validation for performance optimisation:
+
+LargeDataset <- interface(
+    data = "data.frame",
+    metadata = "list",
+    validate_on_access = FALSE # Disable validation for performance
+)
+
+big_data <- implement(LargeDataset,
+    data = data.frame(x = 1:1000, y = runif(1000)),
+    metadata = list(source = "simulation", date = Sys.Date())
+)
+
+# No validation on access for better performance
+big_data$data[1, "x"] <- "should be numeric but no error raised"
+
+
+# functions
+typed_fun <- fun(
+    args = list(
+        x = "numeric",
+        y = "numeric"
+    ),
+    return = "numeric",
+    impl = function(x, y) {
+        return(x + y)
+    }
+)
+
+# at run time if the user inputs or a output is not of the expected type, an error will be raised
+try(typed_fun("a", 2))
+#> Error in typed_fun("a", 2) : Argument 'x' does not match the expected type: numeric
+
+try(typed_fun(1, 2))
+# [1] 3
+
+# allow for multiple return types
+typed_fun2 <- fun(
+    args = list(
+        x = c("numeric", "character"),
+        y = "numeric"
+    ),
+    return = c("numeric", "character"),
+    impl = function(x, y) {
+        if (is.numeric(x)) {
+            return(x + y)
+        } else {
+            return(paste(x, y))
+        }
+    }
+)
+
+try(typed_fun2(1, 2))
+# [1] 3
+
+try(typed_fun2("a", 2))
+# [1] "a 2"
+
+# allow for passing generics in interfaces like typescript does with interface ApiResponse<T>
+# Generics
+# Define a generic interface
+ApiResponse <- generic(function(T) {
+    interface(
+        data = T,
+        status = "numeric",
+        message = "character"
+    )
+})
+
+# Use the generic interface with a specific type
+UserResponse <- ApiResponse(UserProfile)
+
+# Implement the generic interface
+user_response <- UserResponse(
+    data = UserProfile(
+        username = "john_doe",
+        email = "john@example.com",
+        age = 25
+    ),
+    status = 200,
+    message = "User retrieved successfully"
+)
+
+print(user_response$data$username)
+#> [1] "john_doe"
+
+# Another example with a different type
+NumberResponse <- ApiResponse("numeric")
+
+number_response <- NumberResponse(
+    data = 42,
+    status = 200,
+    message = "Number retrieved successfully"
+)
+
+print(number_response$data)
+#> [1] 42
+
+# Generic typed function
+map_data <- generic(function(T, U) {
+    fun(
+        args = list(
+            data = T,
+            mapper = fun(args = list(x = T), return = U)
+        ),
+        return = U,
+        impl = function(data, mapper) {
+            mapper(data)
+        }
+    )
+})
+
+# Use the generic function with specific types
+double_number <- map_data("numeric", "numeric")(
+    data = 21,
+    mapper = function(x) x * 2
+)
+
+print(double_number)
+#> [1] 42
+
+# Using generics with previously defined interfaces
+EmployeeResponse <- ApiResponse(Employee)
+
+employee_response <- EmployeeResponse(
+    data = employee_data,  # Using the previously defined employee_data
+    status = 200,
+    message = "Employee data retrieved successfully"
+)
+
+print(employee_response$data$address$city)
+#> [1] "Data City"