From 66cbbac1cc20ce6d264ed3a58e001a41b39d88d8 Mon Sep 17 00:00:00 2001
From: Simon Forman <sforman@hushmail.com>
Date: Wed, 1 Feb 2023 18:35:11 -0800
Subject: [PATCH] Minor cleanup.

---
 implementations/C/parser.c | 84 +++++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 37 deletions(-)

diff --git a/implementations/C/parser.c b/implementations/C/parser.c
index ba35cb0..e7241af 100644
--- a/implementations/C/parser.c
+++ b/implementations/C/parser.c
@@ -5,54 +5,64 @@
 
 
 const char *BLANKS = " \t";
-const char *TEXT = "hi there  fr  [[]  ie]nd]  []    23    ";
-/*                  01234567890123456789
-                       ^     ^
-*/
+const char *TEXT = " 23 [dup   *] i hi there  fr  [[]  ie]nd]  []    23      ";
+
 
 char *
 trim_leading_blanks(char *str)
 {
-        size_t offset = strspn(str, BLANKS);
-        if (offset == strlen(str)) {
-                /* All blanks. */
-                return NULL;
-        }
-        return str + offset;
+	size_t offset = strspn(str, BLANKS);
+	return (offset == strlen(str)) ? NULL : (str + offset);
 }
 
+
 int
 main(void)
 {
 	char *rest, *text, *snip;
 	ptrdiff_t diff;
 
-        text = trim_leading_blanks((char *)TEXT);
-	rest = strpbrk(text, " []");
-	while (NULL != rest) {
-                /* How many chars have we got? */
-		diff = rest - text;
-
-                if (diff) {
-                        /* Allocate space and copy out the substring. */
-                        snip = (char *)GC_malloc(diff + 1);
-                        strncat(snip, text, diff);
-                        printf("%s\n", snip);
-                }
-
-                /* The next char is a space or '[' or ']'. */
-                if ('[' == rest[0] || ']' == rest[0]) {
-                        printf("%c\n", rest[0]);
-                }
-
-                /*  */
-                text = trim_leading_blanks(++rest);
-                /*printf(">>>%s\n\n", text);*/
-
-                /* calling strpbrk on NULL caused segfault! */
-                rest = (NULL != text) ? strpbrk(text, " []") : text;
+	text = trim_leading_blanks((char *)TEXT);
+	if (NULL == text) {
+		/* All blanks. */
+		return 1;
+	}
+
+	rest = strpbrk(text, " []");
+	/*
+	rest now points to a space or '[' or ']' after a term,
+	-or- it is NULL if the rest of the string is a single term
+	with no spaces nor brackets.
+	*/
+
+	while (NULL != rest) {
+
+		/* How many chars have we got? */
+		diff = rest - text;
+		/*
+		diff can be zero when there is more than one space in
+		a sequence in the input string.  This won't happen on
+		the first iteration but it can on later iterations.
+		*/
+
+		if (diff) {
+			/* Allocate space and copy out the substring. */
+			snip = (char *)GC_malloc(diff + 1);
+			strncat(snip, text, diff);
+			printf("%s\n", snip);
+		}
+
+		/* The next char is a space or '[' or ']'. */
+		if ('[' == rest[0] || ']' == rest[0]) {
+			printf("%c\n", rest[0]);
+		}
+
+		text = trim_leading_blanks(++rest);
+
+		/* calling strpbrk on NULL caused segfault! */
+		rest = (NULL != text) ? strpbrk(text, " []") : text;
+	}
+	if (text) {
+		printf("%s\n", text);
 	}
-        if (text) {
-                printf("%s\n", text);
-        }
 }