#!/usr/bin/sed -f
# SPDX-FileCopyrightText: 2026 Lady <https://www.ladys.computer/about/#lady>
# SPDX-License-Identifier: MPL-2.0

## ⋯ 🧮🖍 Codemark ∷ sed ∷ syntax-comment.sed
##
## ⁌ The “syntax comment” Sed program
##
## ] Copyright © 2026 Lady [@ Ladys Computer].
## ]
## ] This Source Code Form is subject to the terms of the Mozilla
## ]   Public License, version 2.0.
## ] If a copy of the M·P·L was not distributed with this file, You
## ]   can obtain one at {🔗<https://mozilla.org/MPL/2.0/>}.

## The program begins in the “outside” state.
## When a line starting with `|´ is encountered, it prints a syntax
##   comment and switches to the “inside” state.

:outside
/^|/{
  s/^|/|⌦syntax:⌫/
  b inside
}

## If the line did not begin with `|´, the program advances and stays
##   “outside”.

n
b outside

## Once “inside”, the program advances and switches to “outside” as
##   soon as it encounters a line which does not begin with a `|´.
## Otherwise, it stays “inside”.

:inside
n
/^|/!b outside
b inside