From 670598a4db2f60f84e14593bb48c3fe039328a67 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Mon, 23 Jul 2012 23:37:08 +0200
Subject: [PATCH] Simplified CSV and WS parsers

---
 xsv.c | 54 +++++++++++++++++++++++++++++-------------------------
 1 file changed, 29 insertions(+), 25 deletions(-)

diff --git a/xsv.c b/xsv.c
index 7ec94da..4ad9e47 100644
--- a/xsv.c
+++ b/xsv.c
@@ -90,17 +90,17 @@ static struct field *in_field;
 static line_t in_line;
 static int line_number;
 
-static void new_field(void)
+static void new_field(int pos)
 {
 	in_field = fields_push(&in_fields);
-	in_field->start_pos = line_count(&in_line);
+	in_field->start_pos = pos;
 	in_field->len = 0;
 }
 
-static void ensure_field(void)
+static void ensure_field(int pos)
 {
 	if (!in_field)
-		new_field();
+		new_field(pos);
 }
 
 static void warn(struct format *fmt, char *msg, ...)
@@ -134,6 +134,7 @@ static int csv_read(void)
 	int quoted = 0;
 	for (;;) {
 		int c = getchar();
+		int i = line_count(&in_line);
 restart:
 		if (c == '\r')
 			continue;
@@ -159,11 +160,11 @@ restart:
 			quoted = 1;
 			continue;
 		} else if (c == in_format->fs && !quoted) {
-			ensure_field();
-			new_field();
+			ensure_field(i);
+			new_field(i);
 			continue;
 		}
-		ensure_field();
+		ensure_field(i);
 		*line_push(&in_line) = c;
 		in_field->len++;
 	}
@@ -209,27 +210,32 @@ static void csv_write(void)
 
 static int ws_read(void)
 {
+	if (!next_line())
+		return 0;
+
+	unsigned char *line = line_first(&in_line);
+	int n = line_count(&in_line);
+	if (!n)
+		return 1;
+
 	int ws = 0;
-	for (;;) {
-		int c = getchar();
-		if (c < 0)
-			return !!fields_count(&in_fields);
-		if (c == '\r')
-			continue;
-		if (c == '\n')
-			return 1;
+	new_field(0);
+	for (int i=0; i<n; i++) {
+		int c = line[i];
 		if (is_ws(c)) {
-			ensure_field();
-			if (!ws)
-				new_field();
 			ws++;
 		} else {
-			ensure_field();
-			*line_push(&in_line) = c;
+			if (ws) {
+				new_field(i);
+				ws = 0;
+			}
 			in_field->len++;
-			ws = 0;
 		}
 	}
+
+	if (ws)
+		new_field(n);
+	return 1;
 }
 
 static const char *regex_set(struct format *f, char *rx)
@@ -265,13 +271,11 @@ static int regex_read(void)
 			if (sep != PCRE_ERROR_NOMATCH)
 				warn(in_format, "PCRE matching error %d", sep);
 			// No further occurrence of the separator: the rest is a single field
-			new_field();
-			in_field->start_pos = i;
+			new_field(i);
 			in_field->len = n - i;
 			return 1;
 		}
-		new_field();
-		in_field->start_pos = i;
+		new_field(i);
 		in_field->len = ovec[0] - i;
 		i = ovec[1];
 	}
-- 
2.39.2