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Merged
mattt merged 2 commits into from
Dec 5, 2025
Merged

Remove length marker option #14

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7b50a36
Remove length marker option
mattt Dec 5, 2025
5d7ed96
Reject length markers during decoding (#15)
mattt Dec 5, 2025
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28 changes: 0 additions & 28 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -168,34 +168,6 @@ items[2|]{sku|name|qty|price}:
B2|Gadget|1|14.5
```

#### Length Markers

Add a `#` prefix to array lengths for emphasis and readability:

```swift
let data = [
"tags": ["reading", "gaming", "coding"],
"items": [
["sku": "A1", "qty": 2, "price": 9.99],
["sku": "B2", "qty": 1, "price": 14.5]
]
]

let encoder = TOONEncoder()
encoder.lengthMarker = .hash

let output = try encoder.encode(data)
```

Output:

```
tags[#3]: reading,gaming,coding
items[#2]{sku,qty,price}:
A1,2,9.99
B2,1,14.5
```

#### Tabular Arrays

Arrays of objects with identical primitive fields use an efficient tabular format:
Expand Down
49 changes: 8 additions & 41 deletions Sources/ToonFormat/Encoder.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -12,9 +12,6 @@ public final class TOONEncoder {
/// The delimiter to use for array values and tabular rows.
public var delimiter: Delimiter = .comma

/// An optional marker to prefix array lengths in headers.
public var lengthMarker: LengthMarker = .none

/// Key folding mode for collapsing single-key object chains into dotted paths.
///
/// When enabled, single-key nested objects like `{ a: { b: { c: 1 } } }`
Expand Down Expand Up @@ -87,34 +84,11 @@ public final class TOONEncoder {
case pipe = "|"
}

/// A marker character to prefix array lengths in headers.
///
/// Length markers appear before array counts in brackets
/// to provide additional clarity about array sizing.
///
/// Example with `.none`:
/// ```toon
/// tags[3]: reading,gaming,coding
/// ```
///
/// Example with `.hash`:
/// ```toon
/// tags[#3]: reading,gaming,coding
/// ```
public enum LengthMarker: CaseIterable, Hashable, Sendable {
/// No length marker.
case none

/// Hash symbol prefix (`#`).
case hash
}

/// Creates a new TOON encoder with default configuration.
///
/// Default settings:
/// - `indent`: 2 spaces
/// - `delimiter`: `.comma`
/// - `lengthMarker`: `.none`
/// - `keyFolding`: `.disabled`
/// - `flattenDepth`: `Int.max`
public init() {}
Expand Down Expand Up @@ -356,8 +330,7 @@ public final class TOONEncoder {
length: array.count,
key: firstKey,
fields: header,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
write(
depth: depth,
Expand Down Expand Up @@ -446,8 +419,7 @@ public final class TOONEncoder {
let header = formatHeader(
length: 0,
key: key,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
write(depth: depth, content: header, to: &output)
return
Expand Down Expand Up @@ -515,8 +487,7 @@ public final class TOONEncoder {
let header = formatHeader(
length: values.count,
key: key,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
write(depth: depth, content: header, to: &output)

Expand All @@ -538,8 +509,7 @@ public final class TOONEncoder {
length: rows.count,
key: key,
fields: header,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
write(depth: depth, content: headerStr, to: &output)

Expand All @@ -555,8 +525,7 @@ public final class TOONEncoder {
let header = formatHeader(
length: items.count,
key: key,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
write(depth: depth, content: header, to: &output)

Expand Down Expand Up @@ -703,8 +672,7 @@ public final class TOONEncoder {
let header = formatHeader(
length: values.count,
key: key,
delimiter: delimiter.rawValue,
lengthMarker: lengthMarker == .hash ? "#" : nil
delimiter: delimiter.rawValue
)
let joinedValue = joinEncodedValues(values, delimiter: delimiter.rawValue)

Expand All @@ -718,8 +686,7 @@ public final class TOONEncoder {
length: Int,
key: String? = nil,
fields: [String]? = nil,
delimiter: String = ",",
lengthMarker: String? = nil
delimiter: String = ","
) -> String {
var header = ""

Expand All @@ -729,7 +696,7 @@ public final class TOONEncoder {

// Only include delimiter if it's not the default (comma)
let delimiterSuffix = delimiter != "," ? delimiter : ""
header += "[\(lengthMarker ?? "")\(length)\(delimiterSuffix)]"
header += "[\(length)\(delimiterSuffix)]"

if let fields = fields {
let quotedFields = fields.map { encodeKey($0) }
Expand Down
14 changes: 0 additions & 14 deletions Tests/ToonFormatTests/DecoderTests.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -1458,20 +1458,6 @@ struct DecoderTests {
#expect(original == decoded)
}

@Test func roundTripLengthMarker() async throws {
struct LengthMarkerObject: Codable, Equatable {
let tags: [String]
}

let encoder = TOONEncoder()
encoder.lengthMarker = .hash

let original = LengthMarkerObject(tags: ["reading", "gaming", "coding"])
let encoded = try encoder.encode(original)
let decoded = try decoder.decode(LengthMarkerObject.self, from: encoded)
#expect(original == decoded)
}

@Test func roundTripKeyFolding() async throws {
struct NestedObject: Codable, Equatable {
struct User: Codable, Equatable {
Expand Down
94 changes: 0 additions & 94 deletions Tests/ToonFormatTests/EncoderTests.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -1123,100 +1123,6 @@ struct EncoderTests {
#expect(tabCommaResult.contains("tags[2\t]: a,b\tc,d"))
}

// MARK: - Length Marker Option

@Test func lengthMarkerHash() async throws {
let encoder = TOONEncoder()
encoder.lengthMarker = .hash

struct LengthMarkerTestObject: Codable {
let tags: [String]
let items: [String]
}

let lengthMarkerObj = LengthMarkerTestObject(tags: ["reading", "gaming", "coding"], items: [])
let result = String(data: try encoder.encode(lengthMarkerObj), encoding: .utf8)!

#expect(result.contains("tags[#3]: reading,gaming,coding"))
#expect(result.contains("items[#0]:"))
}

@Test func lengthMarkerWithTabularArrays() async throws {
let encoder = TOONEncoder()
encoder.lengthMarker = .hash

struct TabularLengthMarkerObject: Codable {
let sku: String
let qty: Int
let price: Double
}

struct TabularLengthMarkerArrayObject: Codable {
let items: [TabularLengthMarkerObject]
}

let tabularLengthMarkerObj = TabularLengthMarkerArrayObject(items: [
TabularLengthMarkerObject(sku: "A1", qty: 2, price: 9.99),
TabularLengthMarkerObject(sku: "B2", qty: 1, price: 14.5),
])
let tabularLengthMarkerResult = String(
data: try encoder.encode(tabularLengthMarkerObj),
encoding: .utf8
)!
#expect(tabularLengthMarkerResult.contains("items[#2]{sku,qty,price}:"))
#expect(tabularLengthMarkerResult.contains(" A1,2,9.99"))
#expect(tabularLengthMarkerResult.contains(" B2,1,14.5"))
}

@Test func lengthMarkerWithNestedArrays() async throws {
let encoder = TOONEncoder()
encoder.lengthMarker = .hash

struct NestedLengthMarkerObject: Codable {
let pairs: [[String]]
}

let nestedLengthMarkerObj = NestedLengthMarkerObject(pairs: [["a", "b"], ["c", "d"]])
let nestedLengthMarkerResult = String(
data: try encoder.encode(nestedLengthMarkerObj),
encoding: .utf8
)!
#expect(nestedLengthMarkerResult.contains("pairs[#2]:"))
#expect(nestedLengthMarkerResult.contains(" - [#2]: a,b"))
#expect(nestedLengthMarkerResult.contains(" - [#2]: c,d"))
}

@Test func lengthMarkerWithDelimiter() async throws {
let encoder = TOONEncoder()
encoder.lengthMarker = .hash
encoder.delimiter = .pipe

struct LengthMarkerTestObject: Codable {
let tags: [String]
}

let lengthMarkerObj = LengthMarkerTestObject(tags: ["reading", "gaming", "coding"])
let delimiterLengthMarkerResult = String(
data: try encoder.encode(lengthMarkerObj),
encoding: .utf8
)!
#expect(delimiterLengthMarkerResult.contains("tags[#3|]: reading|gaming|coding"))
}

@Test func lengthMarkerNone() async throws {
let encoder = TOONEncoder()
encoder.lengthMarker = .none
encoder.delimiter = .pipe

struct LengthMarkerTestObject: Codable {
let tags: [String]
}

let lengthMarkerObj = LengthMarkerTestObject(tags: ["reading", "gaming", "coding"])
let noMarkerResult = String(data: try encoder.encode(lengthMarkerObj), encoding: .utf8)!
#expect(noMarkerResult.contains("tags[3|]: reading|gaming|coding"))
}

// MARK: - Non-JSON-serializable Values

@Test func dateConversion() async throws {
Expand Down