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Diffstat (limited to 'tools/codegen/src/com/android/codegen/Printer.kt')
| -rw-r--r-- | tools/codegen/src/com/android/codegen/Printer.kt | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/tools/codegen/src/com/android/codegen/Printer.kt b/tools/codegen/src/com/android/codegen/Printer.kt new file mode 100644 index 000000000000..b30e3f68b307 --- /dev/null +++ b/tools/codegen/src/com/android/codegen/Printer.kt @@ -0,0 +1,186 @@ +/* + * Copyright (C) 2019 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + + +package com.android.codegen + +/** + * Mixin for syntactic sugar around indent-aware printing into [stringBuilder] + */ +interface Printer<SELF: Printer<SELF>> { + + val stringBuilder: StringBuilder + + var currentIndent: String + + fun pushIndent() { + currentIndent += INDENT_SINGLE + } + + fun popIndent() { + currentIndent = if (currentIndent.length >= INDENT_SINGLE.length) { + currentIndent.substring(0, currentIndent.length - INDENT_SINGLE.length) + } else { + "" + } + } + + fun backspace() = stringBuilder.setLength(stringBuilder.length - 1) + val lastChar get() = stringBuilder[stringBuilder.length - 1] + + private fun appendRaw(s: String) { + stringBuilder.append(s) + } + + fun append(s: String) { + if (s.isBlank() && s != "\n") { + appendRaw(s) + } else { + appendRaw(s.lines().map { line -> + if (line.startsWith(" *")) line else line.trimStart() + }.joinToString("\n$currentIndent")) + } + } + + fun appendSameLine(s: String) { + while (lastChar.isWhitespace() || lastChar.isNewline()) { + backspace() + } + appendRaw(s) + } + + fun rmEmptyLine() { + while (lastChar.isWhitespaceNonNewline()) backspace() + if (lastChar.isNewline()) backspace() + } + + /** + * Syntactic sugar for: + * ``` + * +"code()"; + * ``` + * to append the given string plus a newline + */ + operator fun String.unaryPlus() = append("$this\n") + + /** + * Syntactic sugar for: + * ``` + * !"code()"; + * ``` + * to append the given string without a newline + */ + operator fun String.not() = append(this) + + /** + * Syntactic sugar for: + * ``` + * ... { + * ... + * }+";" + * ``` + * to append a ';' on same line after a block, and a newline afterwards + */ + operator fun Unit.plus(s: String) { + appendSameLine(s) + +"" + } + + /** + * A multi-purpose syntactic sugar for appending the given string plus anything generated in + * the given [block], the latter with the appropriate deeper indent, + * and resetting the indent back to original at the end + * + * Usage examples: + * + * ``` + * "if (...)" { + * ... + * } + * ``` + * to append a corresponding if block appropriate indentation + * + * ``` + * "void foo(...)" { + * ... + * } + * ``` + * similar to the previous one, plus an extra empty line after the function body + * + * ``` + * "void foo(" { + * <args code> + * } + * ``` + * to use proper indentation for args code and close the bracket on same line at end + * + * ``` + * "..." { + * ... + * } + * to use the correct indentation for inner code, resetting it at the end + */ + operator fun String.invoke(block: SELF.() -> Unit) { + if (this == " {") { + appendSameLine(this) + } else { + append(this) + } + when { + endsWith("(") -> { + indentedBy(2, block) + appendSameLine(")") + } + endsWith("{") || endsWith(")") -> { + if (!endsWith("{")) appendSameLine(" {") + indentedBy(1, block) + +"}" + if ((endsWith(") {") || endsWith(")") || this == " {") + && !startsWith("synchronized") + && !startsWith("switch") + && !startsWith("if ") + && !contains(" else ") + && !contains("new ") + && !contains("return ")) { + +"" // extra line after function definitions + } + } + else -> indentedBy(2, block) + } + } + + fun indentedBy(level: Int, block: SELF.() -> Unit) { + append("\n") + level times { + append(INDENT_SINGLE) + pushIndent() + } + (this as SELF).block() + level times { popIndent() } + rmEmptyLine() + +"" + } + + fun Iterable<FieldInfo>.forEachTrimmingTrailingComma(b: FieldInfo.() -> Unit) { + forEachApply { + b() + if (isLast) { + while (lastChar == ' ' || lastChar == '\n') backspace() + if (lastChar == ',') backspace() + } + } + } +}
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