Fix f() and g() functions, with help of remembering(1) and highlight(1)

2 files changed, 166 insertions, 33 deletions

diff --git a/bin/highlight b/bin/highlight
new file mode 100755
index 0000000..70cf5ff
--- /dev/null
+++ b/bin/highlight
@@ -0,0 +1,91 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  highlight -n LINE_NUMBER -e PATTERN -f FILENAME
+		  highlight -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+
+		Options:
+		  -n LINE_NUMBER    the specific line number to highligh
+		  -e PATTERN        the pattern to highlight all over the file
+		  -f FILENAME       the file to be processed
+		  -h, --help        show this message
+
+
+		Highlight FILENAME:
+		  a) with an ANSI background color on LINE_NUMBER;
+		  b) with an ANSI foreground color on every occurrence of PATTERN.
+
+		Useful as a tool for development workflow, when one wants to
+		show a specific matched line, and at the same time visualize all
+		other ocurrences of PATTERN.
+
+
+		Examples:
+
+		  Highlight the line 10 of Makefile, and all occurences of "lisp":
+
+		    $ highlight -n10 -e 'lisp' -f Makefile
+	EOF
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'n:e:f:h' flag; do
+	case "$flag" in
+		n)
+			LINE_NUMBER="$OPTARG"
+			;;
+		e)
+			PATTERN="$OPTARG"
+			;;
+		f)
+			FILENAME="$OPTARG"
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+eval "$(assert-arg -- "${LINE_NUMBER:-}" '-n LINE_NUMBER')"
+eval "$(assert-arg -- "${PATTERN:-}"     '-e PATTERN')"
+eval "$(assert-arg -- "${FILENAME:-}"    '-f FILENAME')"
+
+
+
+graybg="$(printf '\033[7;2;40m')"
+end="$(printf '\033[0m')"
+
+grep -E --color=always -e ^ -e "$PATTERN" "$FILENAME" |
+	perl -pe "s/\x1b\[m/${end}${graybg}/g if $. == $LINE_NUMBER" |
+	sed "${LINE_NUMBER}s|^\(.*\)\$|${graybg}\\1${end}|"
diff --git a/etc/sh/rc b/etc/sh/rc
index b49440a..f2de817 100644
--- a/etc/sh/rc
+++ b/etc/sh/rc
@@ -256,43 +256,85 @@ PS1='`error_marker`'$(timestamp)' '$(path)' `shell_status``vcs ps1``guix_env``in
 
 
 
-# g '^\w.*json_destroy('
 g() {
-  # shellcheck disable=2086
-  fn=$(git grep -n -- "$1" ${2:-} | \
-         cut -d: -f -2            | \
-         fzf --select-1 \
-             --exit-0   \
-             --preview "echo {}       | \
-                          cut -d: -f1 | \
-                          xargs -I% awk -v bounds=25 -v pat=\"$1\" -v n=\$(echo {} | cut -d: -f2) '
-                            (n - bounds < NR) && (NR < n + bounds) && (NR != n) { print }
-                            NR==n { gsub(pat, \"\033[1;33m&\033[1;000m\"); print }
-                          ' %")
-  if [ -n "$fn" ]; then
-    f="$(echo "$fn" | cut -d: -f1)"
-    n="$(echo "$fn" | cut -d: -f2)"
-    # shellcheck disable=2068
-    # history -s g "$@"
-    # history -s vi "+$n" "$f"
-    # vi "+$n" "$f"
-    history -s g "$@"
-    history -s e "+$n" "$f"
-    e "+$n" "$f"
-  fi
+	if [ -z "${1:-}" ]; then
+		cat <<-'EOF'
+			Missing PATTERN.
+
+			Usage:
+			  g PATTERN [PATH]
+		EOF
+		return 2
+	fi
+	PAT="$(mkstemp)-g-shell-function"
+	printf '%s' "$1" > "$PAT"
+	PREVIEW_CMD="highlight -n{2} -f{1} -e \"\$(cat '$PAT')\""
+
+	LINE="$(
+		# shellcheck disable=2086
+		git grep --color=always -n -- "$(cat "$PAT")" ${2:-} |
+			fzf \
+				--exit-0                    \
+				--select-1                  \
+				--ansi                      \
+				--delimiter=:               \
+				--preview-window '+{2}+3/3' \
+				--preview "$PREVIEW_CMD"
+	)"
+	rm -f "$(dirname "$PAT")"/*-g-shell-function
+	if [ -n "$LINE" ]; then
+		FILE="$(  echo "$LINE" | cut -d: -f1)"
+		NUMBER="$(echo "$LINE" | cut -d: -f2)"
+		case "$1" in
+			"'"*"'")
+				# Best effort handling of string escaping, since
+				# one can't recover what was typed at this level
+				H="\"$1\""
+				;;
+			*)
+				H="'$1'"
+				;;
+		esac
+		if [ -z "${2:-}" ]; then
+			history -s g "$H"
+		else
+			history -s g "$H" "'$2'"
+		fi
+		history -s "$VISUAL" +"$NUMBER" "'$FILE'"
+		"$VISUAL" +"$NUMBER" "$FILE"
+	fi
 }
 
 f() {
-  # profile="f-shell-function$(pwd | sed -e 's_/_-_g')"
-  # file="$(git ls-files | grep ${2:-.} | remembering -p "$profile" -c "fzf --select-1 --exit-0 --preview 'cat {}'")"
-  # shellcheck disable=2086
-  file="$(git ls-files | grep ${2:-.} | fzf --select-1 --exit-0 --preview 'cat {}')"
-  if [ -n "$file" ]; then
-    # shellcheck disable=2068
-    history -s f "$@"
-    history -s "${1:-$EDITOR}" "$file"
-    "${1:-$EDITOR}" "$file"
-  fi
+	P="f-shell-function$(pwd | sed 's|/|-|g')"
+	F="$(
+		git ls-files |
+			grep -E -e "${2:-.}" |
+			remembering -p "$P" -- \
+				fzf --select-1 --exit-0 --preview 'cat {}'
+	)"
+	CMD="${1:-$VISUAL}"
+	if [ -n "$F" ]; then
+		if [ -z "${1:-}" ]; then
+			history -s f
+		elif [ -z "${2:-}" ]; then
+			history -s f "$1"
+		else
+			history -s f "$1" "'$2'"
+		fi
+
+		case "$F" in
+			-*)
+				DELIM='--'
+				;;
+			*)
+				DELIM=''
+				;;
+		esac
+		history -s "$CMD" $DELIM "'$F'"
+
+		"$CMD" -- "$F"
+	fi
 }