Merge pull request 'Markdownテーブル形式に対応' (#8) from feature/markdown-table-format into main

Reviewed-on: #8

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Yuya KAMATAKI and contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -15,10 +15,11 @@ TSVへ変換したり、Excelからコピーした表を再び構造化データ
 - CSV
 - TSV
 - XLSX
+- Markdown table (`markdown` / `md`)
 
 ## インストール
 
-Go 1.25以上が必要です。
+Go 1.25.13以上が必要です。
 
 ```sh
 go install git.rumginger.org/agent/dataxl/cmd/dataxl@latest
@@ -55,6 +56,12 @@ JSONからExcel workbookを作成:
 dataxl -from json -to xlsx -i people.json -o people.xlsx
 ```
 
+Markdownのテーブルを作成:
+
+```sh
+dataxl -from yaml -to markdown -i examples/people.yaml -o people.md
+```
+
 Excel workbookをYAMLへ変換:
 
 ```sh
@@ -86,6 +93,15 @@ Excelから戻す場合は、シート上の範囲をコピーしてstdinへ渡
 dataxl -from tsv -to yaml > restored.yaml
 ```
 
+## Markdownテーブル
+
+GitHub Flavored Markdown互換のヘッダー・区切り行を持つテーブルを読み書きできます。
+外側の `|` は省略可能で、区切り行の `:` による左寄せ・中央寄せ・右寄せ指定も
+入力時に受け付けます（配置指定自体は保持しません）。
+
+セル内の `|` とバックスラッシュはMarkdownのbackslash escapeを使用します。
+改行や前後の空白・タブはHTML文字参照として表し、表形式間の変換で保持します。
+
 ## 入れ子構造の表現
 
 構造化データの入れ子は、Excelで編集しやすい列名へ展開されます。
@@ -154,8 +170,8 @@ CSV、TSV、XLSXから構造化形式へ戻す際は、セル文字列を次の
 
 - `-i`: 入力ファイル。省略時はstdin。
 - `-o`: 出力ファイル。省略時はstdout。
-- `-from`: 入力形式。`json`, `yaml`, `toml`, `csv`, `tsv`, `xlsx`。
+- `-from`: 入力形式。`json`, `yaml`, `toml`, `csv`, `tsv`, `xlsx`, `markdown`。
-- `-to`: 出力形式。`json`, `yaml`, `toml`, `csv`, `tsv`, `xlsx`。
+- `-to`: 出力形式。`json`, `yaml`, `toml`, `csv`, `tsv`, `xlsx`, `markdown`。
 - `-sheet`: XLSXの読み書きに使うシート名。既定値は `Sheet1`。
 - `-pretty`: JSONなどの構造化出力を整形するか。既定値は `true`。
 - `-version`: バージョンを表示して終了します。
@@ -175,3 +191,8 @@ CSV、TSV、XLSXから構造化形式へ戻す際は、セル文字列を次の
 
 - 設計概要: [docs/architecture.md](docs/architecture.md)
 - 開発手順: [docs/development.md](docs/development.md)
+
+## License
+
+dataxlは[MIT License](LICENSE)で提供します。配布バイナリに含まれる依存ソフトウェアの
+著作権表示とライセンスは[THIRD_PARTY_LICENSES.txt](THIRD_PARTY_LICENSES.txt)を参照してください。

THIRD_PARTY_LICENSES.txt

@@ -0,0 +1,764 @@
+THIRD-PARTY SOFTWARE NOTICES
+
+This file contains license notices for third-party software included in the distributed binary.
+
+================================================================================
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+License: BSD-3-Clause
+Source: https://go.dev/LICENSE
+
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+
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+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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+THE SOFTWARE.
+
+================================================================================
+Package: github.com/richardlehane/mscfb
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+Source: https://github.com/richardlehane/mscfb/blob/v1.0.7/LICENSE.txt
+
+
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+================================================================================
+Package: github.com/richardlehane/msoleps/types
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+Source: https://github.com/richardlehane/msoleps/blob/v1.0.6/LICENSE.txt
+
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
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+      and distribution as defined by Sections 1 through 9 of this document.
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+      with Licensor regarding such Contributions.
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+      appropriateness of using or redistributing the Work and assume any
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+      other commercial damages or losses), even if such Contributor
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+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
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+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
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+
+   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
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+
+================================================================================
+Package: github.com/tiendc/go-deepcopy
+License: MIT
+Source: https://github.com/tiendc/go-deepcopy/blob/v1.7.2/LICENSE
+
+MIT License
+
+Copyright (c) 2023 tiendc
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+================================================================================
+Package: github.com/xuri/efp
+License: BSD-3-Clause
+Source: https://github.com/xuri/efp/blob/v0.0.1/LICENSE
+
+BSD 3-Clause License
+
+Copyright (c) 2017 - 2025 Ri Xu All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of efp nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+================================================================================
+Package: github.com/xuri/excelize/v2
+License: BSD-3-Clause
+Source: https://github.com/xuri/excelize/blob/v2.11.0/LICENSE
+
+BSD 3-Clause License
+
+Copyright (c) 2016-2026 The excelize Authors.
+Copyright (c) 2011-2017 Geoffrey J. Teale
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the copyright holder nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+================================================================================
+Package: github.com/xuri/nfp
+License: BSD-3-Clause
+Source: https://github.com/xuri/nfp/blob/2ddeb826f9a9/LICENSE
+
+BSD 3-Clause License
+
+Copyright (c) 2022-2025 Ri Xu All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of nfp nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+================================================================================
+Package: golang.org/x/crypto
+License: BSD-3-Clause
+Source: https://cs.opensource.google/go/x/crypto/+/v0.53.0:LICENSE
+
+Copyright 2009 The Go Authors.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google LLC nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+================================================================================
+Package: golang.org/x/net/html
+License: BSD-3-Clause
+Source: https://cs.opensource.google/go/x/net/+/v0.56.0:LICENSE
+
+Copyright 2009 The Go Authors.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google LLC nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+================================================================================
+Package: golang.org/x/text
+License: BSD-3-Clause
+Source: https://cs.opensource.google/go/x/text/+/v0.39.0:LICENSE
+
+Copyright 2009 The Go Authors.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google LLC nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+================================================================================
+Package: gopkg.in/yaml.v3
+License: MIT
+Source: https://github.com/go-yaml/yaml/blob/v3.0.1/LICENSE
+
+
+This project is covered by two different licenses: MIT and Apache.
+
+#### MIT License ####
+
+The following files were ported to Go from C files of libyaml, and thus
+are still covered by their original MIT license, with the additional
+copyright staring in 2011 when the project was ported over:
+
+    apic.go emitterc.go parserc.go readerc.go scannerc.go
+    writerc.go yamlh.go yamlprivateh.go
+
+Copyright (c) 2006-2010 Kirill Simonov
+Copyright (c) 2006-2011 Kirill Simonov
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+### Apache License ###
+
+All the remaining project files are covered by the Apache license:
+
+Copyright (c) 2011-2019 Canonical Ltd
+
+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.

cmd/dataxl/conversion.go

@@ -51,6 +51,8 @@ func normalizeFormat(format string) string {
 	switch format {
 	case "yml":
 		return "yaml"
+	case "md", "mdown", "mkd":
+		return "markdown"
 	case "xlsm", "xls":
 		return "xlsx"
 	default:
@@ -67,7 +69,7 @@ func inferFormat(path string) string {
 
 func validateFormat(format string) error {
 	switch format {
-	case "json", "yaml", "toml", "csv", "tsv", "xlsx":
+	case "json", "yaml", "toml", "csv", "tsv", "xlsx", "markdown":
 		return nil
 	default:
 		return fmt.Errorf("unsupported format %q", format)
@@ -75,5 +77,5 @@ func validateFormat(format string) error {
 }
 
 func isTabular(format string) bool {
-	return format == "csv" || format == "tsv" || format == "xlsx"
+	return format == "csv" || format == "tsv" || format == "xlsx" || format == "markdown"
 }

cmd/dataxl/conversion_matrix_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestConversionMatrixPreservesRepresentativeTable(t *testing.T) {
-	formats := []string{"json", "yaml", "toml", "csv", "tsv", "xlsx"}
+	formats := []string{"json", "yaml", "toml", "csv", "tsv", "xlsx", "markdown"}
 	records := []any{
 		map[string]any{
 			"active": true,

cmd/dataxl/data_integrity_test.go

@@ -220,7 +220,7 @@ func TestDelimitedSingleEmptyCellRowRoundTrip(t *testing.T) {
 
 func TestStructuredRecordsWithoutScalarFieldsAreRejectedForTables(t *testing.T) {
 	for _, input := range []string{`{}`, `[{}]`} {
-		for _, format := range []string{"csv", "tsv", "xlsx"} {
+		for _, format := range []string{"csv", "tsv", "xlsx", "markdown"} {
 			t.Run(format+"_"+input, func(t *testing.T) {
 				_, err := convert([]byte(input), "json", format, "Sheet1", false)
 				if err == nil || !strings.Contains(err.Error(), "no scalar fields") {
@@ -232,7 +232,7 @@ func TestStructuredRecordsWithoutScalarFieldsAreRejectedForTables(t *testing.T)
 }
 
 func TestEmptyRecordListCanRoundTripThroughDelimitedFormats(t *testing.T) {
-	for _, format := range []string{"csv", "tsv"} {
+	for _, format := range []string{"csv", "tsv", "markdown"} {
 		t.Run(format, func(t *testing.T) {
 			tabular, err := convert([]byte(`[]`), "json", format, "Sheet1", false)
 			if err != nil {

cmd/dataxl/doc.go

@@ -1,7 +1,7 @@
 // Package main implements the dataxl command-line converter.
 //
 // Conversion uses two internal representations: structured Go values for
-// JSON/YAML/TOML and table for CSV/TSV/XLSX. Nested structured values cross the
+// JSON/YAML/TOML and table for CSV/TSV/XLSX/Markdown. Nested structured values cross the
 // boundary through dotted and indexed column paths such as user.name and
 // items[0].sku.
 package main

cmd/dataxl/main.go

@@ -60,8 +60,8 @@ func parseOptions(args []string, stderr io.Writer) (options, error) {
 	fs.SetOutput(stderr)
 	fs.StringVar(&opt.inFile, "i", "", "input file, defaults to stdin")
 	fs.StringVar(&opt.outFile, "o", "", "output file, defaults to stdout")
-	fs.StringVar(&opt.from, "from", "", "input format: json, yaml, toml, csv, tsv, xlsx")
+	fs.StringVar(&opt.from, "from", "", "input format: json, yaml, toml, csv, tsv, xlsx, markdown")
-	fs.StringVar(&opt.to, "to", "", "output format: json, yaml, toml, csv, tsv, xlsx")
+	fs.StringVar(&opt.to, "to", "", "output format: json, yaml, toml, csv, tsv, xlsx, markdown")
 	fs.StringVar(&opt.sheet, "sheet", "Sheet1", "worksheet name for xlsx input/output")
 	fs.BoolVar(&opt.pretty, "pretty", true, "pretty-print structured output")
 	fs.BoolVar(&opt.version, "version", false, "print version and exit")
@@ -72,7 +72,7 @@ func parseOptions(args []string, stderr io.Writer) (options, error) {
   dataxl -from json -to xlsx -i data.json -o data.xlsx
 
 Formats:
-  json, yaml/yml, toml, csv, tsv, xlsx
+  json, yaml/yml, toml, csv, tsv, xlsx, markdown/md
 
 Notes:
   Structured records are flattened into spreadsheet columns such as user.name

cmd/dataxl/main_test.go

@@ -129,6 +129,49 @@ func TestResolveFormatsFromFileExtensions(t *testing.T) {
 	}
 }
 
+func TestResolveMarkdownFormatFromFileExtension(t *testing.T) {
+	opt := options{inFile: "input.json", outFile: "output.md"}
+	if err := opt.resolveFormats(); err != nil {
+		t.Fatal(err)
+	}
+	if opt.from != "json" || opt.to != "markdown" {
+		t.Fatalf("resolved formats = %q -> %q, want json -> markdown", opt.from, opt.to)
+	}
+}
+
+func TestMarkdownTableRoundTrip(t *testing.T) {
+	want := table{
+		Header: []string{"id", "name", "note"},
+		Rows:   [][]string{{"1", "Alice | Bob", "line 1\nline 2\\n"}},
+	}
+	encoded, err := encodeTable(want, "markdown", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := parseTable(encoded, "markdown", "")
+	if err != nil {
+		t.Fatalf("parse generated Markdown: %v\n%s", err, encoded)
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("table = %#v, want %#v\n%s", got, want, encoded)
+	}
+}
+
+func TestMarkdownTableAcceptsAlignmentAndOptionalOuterPipes(t *testing.T) {
+	input := []byte("id | name | note\n---: | :--- | :---:\n1 | Alice \\| Bob | ok\n")
+	got, err := parseTable(input, "markdown", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := table{
+		Header: []string{"id", "name", "note"},
+		Rows:   [][]string{{"1", "Alice | Bob", "ok"}},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("table = %#v, want %#v", got, want)
+	}
+}
+
 func TestVersionFlagDoesNotRequireFormats(t *testing.T) {
 	oldVersion := buildVersion
 	buildVersion = "v9.8.7-test"

cmd/dataxl/table.go

@@ -5,14 +5,16 @@ import (
 	"encoding/csv"
 	"encoding/json"
 	"fmt"
+	"html"
 	"sort"
 	"strconv"
+	"strings"
 	"unicode/utf8"
 
 	"github.com/xuri/excelize/v2"
 )
 
-// table is the common representation for CSV, TSV and XLSX. Rows are padded
+// table is the common representation for CSV, TSV, XLSX and Markdown. Rows are padded
 // to Header width when read, which keeps subsequent conversions rectangular.
 type table struct {
 	Header []string
@@ -36,6 +38,8 @@ func parseTable(input []byte, format, sheet string) (table, error) {
 			return table{}, err
 		}
 		return rowsToTable(rows)
+	case "markdown":
+		return readMarkdown(input)
 	default:
 		return table{}, fmt.Errorf("format %q is not tabular", format)
 	}
@@ -93,11 +97,206 @@ func encodeTable(t table, format, sheet string) ([]byte, error) {
 		return writeDelimited(t, '\t')
 	case "xlsx":
 		return writeXLSX(t, sheet)
+	case "markdown":
+		return writeMarkdown(t)
 	default:
 		return nil, fmt.Errorf("format %q is not tabular", format)
 	}
 }
 
+func readMarkdown(input []byte) (table, error) {
+	input = bytes.TrimPrefix(input, []byte{0xEF, 0xBB, 0xBF})
+	if !utf8.Valid(input) {
+		return table{}, fmt.Errorf("markdown input is not valid UTF-8")
+	}
+	text := strings.ReplaceAll(string(input), "\r\n", "\n")
+	text = strings.TrimSpace(text)
+	if text == "" {
+		return table{}, nil
+	}
+	lines := strings.Split(text, "\n")
+	if len(lines) < 2 {
+		return table{}, fmt.Errorf("markdown table requires a header and separator row")
+	}
+	header, err := parseMarkdownRow(lines[0])
+	if err != nil {
+		return table{}, fmt.Errorf("markdown header: %w", err)
+	}
+	separator, err := parseMarkdownRow(lines[1])
+	if err != nil {
+		return table{}, fmt.Errorf("markdown separator: %w", err)
+	}
+	if len(separator) != len(header) {
+		return table{}, fmt.Errorf("markdown separator has %d fields but the header has %d", len(separator), len(header))
+	}
+	for i, cell := range separator {
+		value := strings.TrimSpace(cell)
+		value = strings.TrimPrefix(value, ":")
+		value = strings.TrimSuffix(value, ":")
+		if len(value) < 3 || strings.Trim(value, "-") != "" {
+			return table{}, fmt.Errorf("markdown separator field %d is invalid", i+1)
+		}
+	}
+	rows := make([][]string, 0, len(lines)-2)
+	for i, line := range lines[2:] {
+		if strings.TrimSpace(line) == "" {
+			continue
+		}
+		row, err := parseMarkdownRow(line)
+		if err != nil {
+			return table{}, fmt.Errorf("markdown row %d: %w", i+3, err)
+		}
+		if len(row) > len(header) {
+			return table{}, fmt.Errorf("row %d has %d fields but the header has %d", i+3, len(row), len(header))
+		}
+		rows = append(rows, padRow(row, len(header)))
+	}
+	return table{Header: header, Rows: rows}, nil
+}
+
+func parseMarkdownRow(line string) ([]string, error) {
+	line = strings.TrimSpace(strings.TrimSuffix(line, "\r"))
+	if strings.HasPrefix(line, "|") {
+		line = line[1:]
+	}
+	if hasUnescapedTrailingPipe(line) {
+		line = strings.TrimSpace(line[:len(line)-1])
+	}
+	var cells []string
+	var cell strings.Builder
+	escaped := false
+	for _, r := range line {
+		if escaped {
+			cell.WriteRune('\\')
+			cell.WriteRune(r)
+			escaped = false
+			continue
+		}
+		if r == '\\' {
+			escaped = true
+			continue
+		}
+		if r == '|' {
+			cells = append(cells, decodeMarkdownCell(strings.Trim(cell.String(), " \t")))
+			cell.Reset()
+			continue
+		}
+		cell.WriteRune(r)
+	}
+	if escaped {
+		return nil, fmt.Errorf("row ends with an incomplete escape")
+	}
+	cells = append(cells, decodeMarkdownCell(strings.Trim(cell.String(), " \t")))
+	return cells, nil
+}
+
+func decodeMarkdownCell(value string) string {
+	var b strings.Builder
+	escaped := false
+	for _, r := range value {
+		if escaped {
+			if r == '\\' || r == '|' {
+				b.WriteRune(r)
+			} else {
+				b.WriteRune('\\')
+				b.WriteRune(r)
+			}
+			escaped = false
+			continue
+		}
+		if r == '\\' {
+			escaped = true
+			continue
+		}
+		b.WriteRune(r)
+	}
+	return html.UnescapeString(b.String())
+}
+
+func hasUnescapedTrailingPipe(line string) bool {
+	line = strings.TrimSpace(line)
+	if !strings.HasSuffix(line, "|") {
+		return false
+	}
+	backslashes := 0
+	for i := len(line) - 2; i >= 0 && line[i] == '\\'; i-- {
+		backslashes++
+	}
+	return backslashes%2 == 0
+}
+
+func writeMarkdown(t table) ([]byte, error) {
+	if len(t.Header) == 0 && len(t.Rows) == 0 {
+		return nil, nil
+	}
+	if len(t.Header) == 0 {
+		return nil, fmt.Errorf("markdown table has rows but no header")
+	}
+	var b strings.Builder
+	writeRow := func(row []string) {
+		b.WriteString("| ")
+		for i, value := range row {
+			if i > 0 {
+				b.WriteString(" | ")
+			}
+			b.WriteString(escapeMarkdownCell(value))
+		}
+		b.WriteString(" |\n")
+	}
+	writeRow(t.Header)
+	b.WriteString("|")
+	for range t.Header {
+		b.WriteString(" --- |")
+	}
+	b.WriteByte('\n')
+	for _, row := range t.Rows {
+		writeRow(padRow(row, len(t.Header)))
+	}
+	return []byte(b.String()), nil
+}
+
+func escapeMarkdownCell(value string) string {
+	leadingEnd := len(value) - len(strings.TrimLeft(value, " \t"))
+	trailingStart := len(strings.TrimRight(value, " \t"))
+	var b strings.Builder
+	for i, r := range value {
+		switch r {
+		case '\\':
+			b.WriteString("\\\\")
+		case '|':
+			b.WriteString("\\|")
+		case '\r':
+			b.WriteString("&#13;")
+		case '\n':
+			b.WriteString("&#10;")
+		case ' ':
+			if i < leadingEnd || i >= trailingStart {
+				b.WriteString("&#32;")
+			} else {
+				b.WriteByte(' ')
+			}
+		case '\t':
+			if i < leadingEnd || i >= trailingStart {
+				b.WriteString("&#9;")
+			} else {
+				b.WriteByte('\t')
+			}
+		default:
+			switch r {
+			case '&':
+				b.WriteString("&amp;")
+			case '<':
+				b.WriteString("&lt;")
+			case '>':
+				b.WriteString("&gt;")
+			default:
+				b.WriteRune(r)
+			}
+		}
+	}
+	return b.String()
+}
+
 func writeDelimited(t table, comma rune) ([]byte, error) {
 	var b bytes.Buffer
 	w := csv.NewWriter(&b)

docs/architecture.md

@@ -3,7 +3,7 @@
 `dataxl` は、ファイル形式ごとの差を小さくするために、内部表現を2つに分けています。
 
 - structured value: JSON/YAML/TOMLから読める `map[string]any`, `[]any`, scalar
-- table: Excel/CSV/TSVに近い `Header []string` と `Rows [][]string`
+- table: Excel/CSV/TSV/Markdownに近い `Header []string` と `Rows [][]string`
 
 変換は原則として次のどれかです。
 
@@ -19,7 +19,7 @@
 - `main.go`: CLI option、stdin/stdout、ファイル入出力
 - `conversion.go`: 変換経路の選択、形式名の正規化・推定
 - `structured.go`: JSON/YAML/TOML adapter
-- `table.go`: CSV/TSV/XLSX adapter、table model、flatten
+- `table.go`: CSV/TSV/XLSX/Markdown adapter、table model、flatten
 - `path.go`: セル値の型推定、列パスのparse、unflatten
 
 `convert` はファイル入出力から独立しているため、CLIを経由せず変換matrixをテストできます。
@@ -40,9 +40,12 @@ type table struct {
 }
 ```
 
-CSV/TSV/XLSXの読み込みでは、短い行を空文字で埋めて列数を揃えます。ヘッダーより
+CSV/TSV/XLSX/Markdownの読み込みでは、短い行を空文字で埋めて列数を揃えます。ヘッダーより
 長い行は、名前のない値を破棄しないようエラーにします。
 XLSXの書き出しではヘッダーを太字にし、1行目を固定します。
+Markdownでは区切り行のalignment markerを受け付けますが、table modelには保持しません。
+セル内のdelimiterとバックスラッシュはbackslash escape、改行と前後空白はHTML文字参照で
+可逆化します。
 
 ## Flattening
 
@@ -129,11 +132,11 @@ TOMLはトップレベル配列を直接表せないため、表からTOMLへ出
 - `gopkg.in/yaml.v3`: YAML読み書き
 - `github.com/BurntSushi/toml`: TOML読み書き
 
-Go 1.25以上を前提にしています。
+Go 1.25.13以上を前提にしています。
 
 ## Error handling
 
 - 未対応形式、decode失敗、workbook/sheet操作失敗は呼び出し元へerrorを返します。
-- CSV/TSVのinvalid UTF-8、headerより長い行、値を持つ空header列を拒否します。
+- CSV/TSV/Markdownのinvalid UTF-8、headerより長い行、値を持つ空header列を拒否します。
 - path復元中の重複header、構文エラー、型競合は変換全体をerrorにします。
 - XLSXのstyle・pane設定も通常の変換errorとして扱い、不完全なworkbookを成功扱いしません。

docs/development.md

@@ -2,7 +2,7 @@
 
 ## Requirements
 
-- Go 1.25 or later
+- Go 1.25.13 or later
 
 ## Setup
 
@@ -44,6 +44,13 @@ Build release archives locally:
 scripts/build-release.sh
 ```
 
+Refresh the checked-in third-party notices after changing dependencies:
+
+```sh
+scripts/update-third-party-licenses.sh
+git diff --exit-code -- THIRD_PARTY_LICENSES.txt
+```
+
 ## Test Coverage
 
 The current tests cover:
@@ -51,6 +58,7 @@ The current tests cover:
 - YAML -> TSV flattening
 - TSV -> JSON path restoration
 - JSON -> XLSX -> JSON round trip
+- Markdown table parsing, escaping, and all-format conversion round trips
 - structured -> structured conversion without CLI/file I/O
 - extension normalization and format inference
 - short table row padding and wider-row rejection
@@ -81,6 +89,9 @@ macOS, and Windows on amd64/arm64, writes `checksums.txt`, creates or reuses a
 Gitea Release, and uploads the generated assets. It uses the built-in
 `${{ secrets.GITEA_TOKEN }}` provided by Gitea Actions.
 
+Each release archive contains the project `LICENSE` and
+`THIRD_PARTY_LICENSES.txt` in addition to the binary and README.
+
 Release binaries receive their tag through the `main.buildVersion` linker
 variable. Verify an extracted native binary with `dataxl -version`.
 

go.mod

@@ -1,6 +1,6 @@
 module git.rumginger.org/agent/dataxl
 
-go 1.25.0
+go 1.25.13
 
 require (
 	github.com/BurntSushi/toml v1.6.0

scripts/build-release.sh

@@ -48,7 +48,7 @@ for target in "${targets[@]}"; do
     -o "$workdir/$binary" \
     ./cmd/dataxl
 
-  cp README.md "$workdir/"
+  cp README.md LICENSE THIRD_PARTY_LICENSES.txt "$workdir/"
 
   if [ "$goos" = "windows" ]; then
     (cd dist && zip -qr "${name}.zip" "$name")

scripts/update-third-party-licenses.sh

@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+temp_dir="$(mktemp -d)"
+trap 'rm -rf "$temp_dir"' EXIT
+
+go_license="$(go env GOROOT)/LICENSE"
+if [ ! -f "$go_license" ] && [ -f /usr/share/licenses/go/LICENSE ]; then
+  go_license=/usr/share/licenses/go/LICENSE
+fi
+if [ ! -f "$go_license" ]; then
+  echo "Go license file was not found" >&2
+  exit 1
+fi
+
+cat >"$temp_dir/template.txt" <<'EOF'
+{{ range . }}================================================================================
+Package: {{ .Name }}
+License: {{ .LicenseName }}
+Source: {{ .LicenseURL }}
+
+{{ .LicenseText }}
+{{ end }}
+EOF
+
+{
+  cat <<'EOF'
+THIRD-PARTY SOFTWARE NOTICES
+
+This file contains license notices for third-party software included in the distributed binary.
+
+================================================================================
+Package: Go standard library
+License: BSD-3-Clause
+Source: https://go.dev/LICENSE
+
+EOF
+  cat "$go_license"
+  printf '\n'
+  cd "$repo_root"
+  go run github.com/google/go-licenses/[email protected] report ./cmd/dataxl \
+    --ignore=git.rumginger.org/agent/dataxl \
+    --template="$temp_dir/template.txt"
+} >"$temp_dir/THIRD_PARTY_LICENSES.txt"
+
+awk '
+  { lines[NR] = $0 }
+  $0 !~ /^[[:space:]]*$/ { last_content_line = NR }
+  END {
+    for (line_number = 1; line_number <= last_content_line; line_number++) {
+      print lines[line_number]
+    }
+  }
+' "$temp_dir/THIRD_PARTY_LICENSES.txt" >"$temp_dir/THIRD_PARTY_LICENSES.normalized.txt"
+
+mv "$temp_dir/THIRD_PARTY_LICENSES.normalized.txt" "$repo_root/THIRD_PARTY_LICENSES.txt"