reuse codeprinter

Author: ktoso

Package.swift

@@ -263,6 +263,10 @@ let package = Package(
       name: "SwiftJavaShared"
     ),
 
+    .target(
+      name: "CodePrinting"
+    ),
+
     .target(
       name: "SwiftJavaToolLib",
       dependencies: [
@@ -277,6 +281,7 @@ let package = Package(
         "JavaNet",
         "SwiftJavaShared",
         "SwiftJavaConfigurationShared",
+        "CodePrinting",
         .product(name: "Subprocess", package: "swift-subprocess"),
       ],
       swiftSettings: [
@@ -324,6 +329,7 @@ let package = Package(
         .product(name: "SwiftJavaJNICore", package: "swift-java-jni-core"),
         "SwiftJavaShared",
         "SwiftJavaConfigurationShared",
+        "CodePrinting",
       ],
       swiftSettings: [
         .swiftLanguageMode(.v5)

Sources/CodePrinting/CodePrinter.swift

@@ -0,0 +1,227 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+// ==== -----------------------------------------------------------------------
+// MARK: CodePrinter
+
+public struct CodePrinter {
+  var contents: String = ""
+
+  var verbose: Bool = false
+
+  var indentationDepth: Int = 0 {
+    didSet {
+      indentationText = String(repeating: indentationPart, count: indentationDepth)
+    }
+  }
+
+  /// String to use for one level of indentationDepth.
+  public var indentationPart: String = "  " {
+    didSet {
+      indentationText = String(repeating: indentationPart, count: indentationDepth)
+    }
+  }
+  public var indentationText: String = ""
+  /// If true, next print() should starts with indentation.
+  var atNewline = true
+
+  public static func toString(_ block: (inout CodePrinter) throws -> Void) rethrows -> String {
+    var printer = CodePrinter()
+    try block(&printer)
+    return printer.finalize()
+  }
+
+  var mode: PrintMode
+  public enum PrintMode {
+    case accumulateAll
+    case flushToFileOnWrite
+  }
+  public init(mode: PrintMode = .flushToFileOnWrite) {
+    self.mode = mode
+  }
+
+  mutating func append(_ text: String) {
+    contents.append(text)
+    if self.verbose {
+      Swift.print(text, terminator: "")
+    }
+  }
+
+  mutating func append<S>(contentsOf text: S)
+  where S: Sequence, S.Element == Character {
+    contents.append(contentsOf: text)
+    if self.verbose {
+      for t in text {
+        Swift.print(t, terminator: "")
+      }
+    }
+  }
+
+  public mutating func printHashIfBlock(
+    _ header: Any,
+    function: String = #function,
+    file: String = #fileID,
+    line: UInt = #line,
+    body: (inout CodePrinter) throws -> Void
+  ) rethrows {
+    print("#if \(header)")
+    indent()
+    try body(&self)
+    outdent()
+    print("#endif // end of \(header)", .sloc, function: function, file: file, line: line)
+  }
+
+  public mutating func printBraceBlock(
+    _ header: Any,
+    parameters: [String]? = nil,
+    function: String = #function,
+    file: String = #fileID,
+    line: UInt = #line,
+    body: (inout CodePrinter) throws -> Void
+  ) rethrows {
+    print("\(header) {", .continue)
+    if let parameters {
+      print(" (\(parameters.joined(separator: ", "))) in", .continue)
+    }
+    println()
+    indent()
+    try body(&self)
+    outdent()
+    print("}", .sloc, function: function, file: file, line: line)
+  }
+
+  public mutating func printParts(
+    _ parts: String...,
+    terminator: PrinterTerminator = .newLine,
+    function: String = #function,
+    file: String = #fileID,
+    line: UInt = #line
+  ) {
+    for part in parts {
+      guard part.trimmingCharacters(in: .whitespacesAndNewlines).count != 0 else {
+        continue
+      }
+
+      self.print(part, terminator, function: function, file: file, line: line)
+    }
+  }
+
+  /// Print a plain newline, e.g. to separate declarations.
+  public mutating func println(
+    _ terminator: PrinterTerminator = .newLine,
+    function: String = #function,
+    file: String = #fileID,
+    line: UInt = #line
+  ) {
+    print("")
+  }
+
+  public mutating func print(
+    _ text: Any,
+    _ terminator: PrinterTerminator = .newLine,
+    function: String = #function,
+    file: String = #fileID,
+    line: UInt = #line
+  ) {
+    let lines = "\(text)".split(separator: "\n", omittingEmptySubsequences: false)
+    var first = true
+    for line in lines {
+      if !first {
+        append("\n")
+        append(indentationText)
+      } else {
+        if atNewline {
+          append(indentationText)
+        }
+        first = false
+      }
+      append(contentsOf: line)
+    }
+
+    if terminator == .sloc {
+      append(" // \(function) @ \(file):\(line)\n")
+      atNewline = true
+    } else {
+      append(terminator.rawValue)
+      atNewline = terminator == .newLine || terminator == .commaNewLine
+    }
+  }
+
+  public mutating func start(_ text: String) {
+    print(text, .continue)
+  }
+
+  public mutating func printSeparator(_ text: String) {
+    assert(!text.contains(where: \.isNewline))
+    print(
+      """
+
+      // ==== --------------------------------------------------
+      // \(text)
+
+      """
+    )
+  }
+
+  public mutating func finalize() -> String {
+    defer { contents = "" }
+    return contents
+  }
+
+  public mutating func indent(file: String = #fileID, line: UInt = #line, function: String = #function) {
+    indentationDepth += 1
+  }
+
+  public mutating func outdent(file: String = #fileID, line: UInt = #line, function: String = #function) {
+    indentationDepth -= 1
+    assert(indentationDepth >= 0, "Outdent beyond zero at [\(file):\(line)](\(function))")
+  }
+
+  public var isEmpty: Bool {
+    self.contents.isEmpty
+  }
+
+  public mutating func dump(file: String = #fileID, line: UInt = #line) {
+    Swift.print("// CodePrinter.dump @ \(file):\(line)")
+    Swift.print(contents)
+  }
+}
+
+// ==== -----------------------------------------------------------------------
+// MARK: PrinterTerminator
+
+public enum PrinterTerminator: String {
+  case newLine = "\n"
+  case space = " "
+  case commaSpace = ", "
+  case commaNewLine = ",\n"
+  case `continue` = ""
+  case sloc = "// <source location>"
+
+  public static func parameterSeparator(_ isLast: Bool) -> Self {
+    if isLast {
+      .continue
+    } else {
+      .commaSpace
+    }
+  }
+
+  public static func parameterNewlineSeparator(_ isLast: Bool) -> Self {
+    if isLast {
+      .newLine
+    } else {
+      .commaNewLine
+    }
+  }
+}