ed

commit 21447b74b0de70994727e99254f4290c3d02d173
parent 74e966a35d5c673629afe47a1b79adba1aa9ddbf
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sat, 12 Dec 2015 18:16:41 +0100

Add subline()

This is a first implementation of subline, which applies
the current substition to a line.

Diffstat:
M
ed.c
 | 
75
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------

1 file changed, 65 insertions(+), 10 deletions(-)
diff --git a/ed.c b/ed.c
@@ -829,24 +829,79 @@ getrhs(int delim)
 	s = NULL;
 }
 
+static int
+getnth(void)
+{
+	int c;
+
+	if ((c = input()) == 'g') {
+		return -1;
+	} else if (isdigit(c)) {
+		return c - '0';
+	} else {
+		back(c);
+		return 1;
+	}
+}
+
+static void
+subline(int num, int nth)
+{
+	char *s, *p, *t, c, *q;
+	size_t siz, cap;
+	static char *line;
+	regmatch_t m[10], *mp;
+
+	free(line);
+	line = NULL;
+
+	p = s = gettxt(num);
+	while (nth--) {
+		if (!regexec(pattern, s, 10, m, 0))
+			return;
+		p += m[0].rm_eo;
+		if (nth <= 0)
+			break;
+	}
+
+	siz = cap = 0;
+	for (t = s; p > t; ++t)
+		line = addchar(*t++, line, &cap, &siz);
+
+	for (t = rhs; c = *t; ++t) {
+		switch (c) {
+		case '\\':
+			if (!isdigit(*t))
+				goto add_char;
+			mp = &m[*t++ - '0'];
+			goto add_string;
+		case '&':
+			mp = &m[0];
+		add_string:
+			for (q = s + mp->rm_so; q < s + mp->rm_eo; ++q)
+				line = addchar(*q, line, &cap, &siz);
+			break;
+		default:
+		add_char:
+			line = addchar(c, line, &cap, &siz);
+			break;
+		}
+	}
+}
+
 static void
 subs(void)
 {
-	int c, delim;
-	int gsub;
+	int delim, nth, i;
+	char *s;
 
 	delim = input();
 	compile(delim);
 	getrhs(delim);
+	nth = getnth();
 
-	if ((c = input()) == 'g') {
-		gsub = -1;
-	} else if (isdigit(c)) {
-		gsub = c - '0';
-	} else {
-		gsub = 1;
-		back(c);
-	}
+	for (i = line1; i <= line2; i = nextln(i))
+		subline(i, nth);
 }
 
 static void