[PATCH 1/2] cli: Parsing. Add option NOTMUCH_OPT_INT_OR_BOOLEAN

[Mark Walters <markwalters1009@gmail.com>]

Allow the option NOTMUCH_OPT_INT_OR_BOOLEAN for command line parsing
which accepts --verbose=3 and --verbose with the latter setting
verbose to 1. It also allows --verbose=0 so (with a little caller
support) user can turn off boolean options.

This means that extra options can be added to the command line
programs in a backwards compatible manner.
---
 command-line-arguments.c |   29 +++++++++++++++++++++++++++--
 command-line-arguments.h |    3 +++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/command-line-arguments.c b/command-line-arguments.c
index e711414..99e13c6 100644
--- a/command-line-arguments.c
+++ b/command-line-arguments.c
@@ -4,6 +4,22 @@
 #include "error_util.h"
 #include "command-line-arguments.h"
 
+/* A helper for parsing an int to a boolean */
+notmuch_bool_t
+notmuch_int_to_boolean (int i)
+{
+    switch (i) {
+	case 1:
+	    return TRUE;
+	case 0:
+	    return FALSE;
+	default:
+	    INTERNAL_ERROR ("Non-boolean value %d", i);
+	    /* UNREACHED */
+	    return FALSE;
+	}
+}
+
 /*
   Search the array of keywords for a given argument, assigning the
   output variable to the corresponding value.  Return FALSE if nothing
@@ -72,6 +88,7 @@ parse_option (const char *arg,
 	if (try->name && strncmp (arg, try->name, strlen (try->name)) == 0) {
 	    char next = arg[strlen (try->name)];
 	    const char *value= arg+strlen(try->name)+1;
+	    enum notmuch_opt_type opt_type = try->opt_type;
 
 	    char *endptr;
 
@@ -79,7 +96,14 @@ parse_option (const char *arg,
 	     * delimiter, and a non-zero length value
 	     */
 
-	    if (try->opt_type != NOTMUCH_OPT_BOOLEAN) {
+	    if (opt_type == NOTMUCH_OPT_INT_OR_BOOLEAN) {
+		if (next != 0)
+		    opt_type = NOTMUCH_OPT_INT;
+		else
+		    opt_type = NOTMUCH_OPT_BOOLEAN;
+	    }
+
+	    if (opt_type != NOTMUCH_OPT_BOOLEAN) {
 		if (next != '=' && next != ':') return FALSE;
 		if (value[0] == 0) return FALSE;
 	    } else {
@@ -89,7 +113,7 @@ parse_option (const char *arg,
 	    if (try->output_var == NULL)
 		INTERNAL_ERROR ("output pointer NULL for option %s", try->name);
 
-	    switch (try->opt_type) {
+	    switch (opt_type) {
 	    case NOTMUCH_OPT_KEYWORD:
 		return _process_keyword_arg (try, value);
 		break;
@@ -107,6 +131,7 @@ parse_option (const char *arg,
 		break;
 	    case NOTMUCH_OPT_POSITION:
 	    case NOTMUCH_OPT_END:
+	    case NOTMUCH_OPT_INT_OR_BOOLEAN: /* should be dealt with above */
 	    default:
 		INTERNAL_ERROR ("unknown or unhandled option type %d", try->opt_type);
 		/*UNREACHED*/
diff --git a/command-line-arguments.h b/command-line-arguments.h
index de1734a..a2fc545 100644
--- a/command-line-arguments.h
+++ b/command-line-arguments.h
@@ -6,6 +6,7 @@
 enum notmuch_opt_type {
     NOTMUCH_OPT_END = 0,
     NOTMUCH_OPT_BOOLEAN,	/* --verbose              */
+    NOTMUCH_OPT_INT_OR_BOOLEAN,	/* --verbose or --verbose=1 */
     NOTMUCH_OPT_INT,		/* --frob=8               */
     NOTMUCH_OPT_KEYWORD,	/* --format=raw|json|text */
     NOTMUCH_OPT_STRING,		/* --file=/tmp/gnarf.txt  */
@@ -76,5 +77,7 @@ parse_position_arg (const char *arg,
 		    int position_arg_index,
 		    const notmuch_opt_desc_t* options);
 
+notmuch_bool_t
+notmuch_int_to_boolean (int i);
 
 #endif
-- 
1.7.9.1