Re: [PATCHv3 1/4] color.h: document and modernize header

[Junio C Hamano]

Stefan Beller  writes:

>  /*
> - * Set the color buffer (which must be COLOR_MAXLEN bytes)
> - * to the raw color bytes; this is useful for initializing
> - * default color variables.
> + * NEEDSWWORK: document this function or refactor grep.c to stop using this
> + * function.
>   */
> -void color_set(char *dst, const char *color_bytes);
> +extern void color_set(char *dst, const char *color_bytes);

The original that is removed by the patch documents the function
well enough; as long as the NEEDSWORK comment is followed through
in a later step in the series, it's alright, though ;-)

> -int git_config_colorbool(const char *var, const char *value);
> -int want_color(int var);
> -int color_parse(const char *value, char *dst);
> -int color_parse_mem(const char *value, int len, char *dst);
> +/*
> + * Parse a config option, which can be a boolean or one of
> + * "never", "auto", "always". Return a constant of
> + * GIT_COLOR_NEVER for "never" or negative boolean,
> + * GIT_COLOR_ALWAYS for "always" or a positive boolean,
> + * and GIT_COLOR_AUTO for "auto".
> + */
> +extern int git_config_colorbool(const char *var, const char *value);

"never" and "always" not being part of usual boolean vocabulary
makes it a bit awkward to explain.

> +/*
> + * Output the formatted string in the specified color (and then reset to 
> normal
> + * color so subsequent output is uncolored). Omits the color encapsulation if
> + * `color` is NULL. The `color_fprintf_ln` prints a new line after resetting
> + * the color. The `color_print_strbuf` prints the given pre-formatted strbuf
> + * instead, up to its first NUL character.
> + */

Obviously, it does not have to be part of this step nor series, but
the above observation makes us realize that color_print_strbuf()
would probably be an unreasonably narrow interface.  It is not too
much to ask the caller to dereference and pass only the .buf
component of the strbuf to an alternative helper that takes "const
char *" and by doing so would allow us to let other callers that do
not have a strbuf but just a plain string use it, too.

Looks good.

[PATCHv3 1/4] color.h: document and modernize header

[Stefan Beller]

Add documentation explaining the functions in color.h.
While at it, mark them extern.

Signed-off-by: Stefan Beller 
---
 color.c |  2 --
 color.h | 58 --
 2 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/color.c b/color.c
index d48dd947c9..c4dc1cb989 100644
--- a/color.c
+++ b/color.c
@@ -399,8 +399,6 @@ static int color_vfprintf(FILE *fp, const char *color, 
const char *fmt,
return r;
 }
 
-
-
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...)
 {
va_list args;
diff --git a/color.h b/color.h
index fd2b688dfb..2e768a10c6 100644
--- a/color.h
+++ b/color.h
@@ -72,26 +72,56 @@ extern int color_stdout_is_tty;
  * Use the first one if you need only color config; the second is a convenience
  * if you are just going to change to git_default_config, too.
  */
-int git_color_config(const char *var, const char *value, void *cb);
-int git_color_default_config(const char *var, const char *value, void *cb);
+extern int git_color_config(const char *var, const char *value, void *cb);
+extern int git_color_default_config(const char *var, const char *value, void 
*cb);
 
 /*
- * Set the color buffer (which must be COLOR_MAXLEN bytes)
- * to the raw color bytes; this is useful for initializing
- * default color variables.
+ * NEEDSWWORK: document this function or refactor grep.c to stop using this
+ * function.
  */
-void color_set(char *dst, const char *color_bytes);
+extern void color_set(char *dst, const char *color_bytes);
 
-int git_config_colorbool(const char *var, const char *value);
-int want_color(int var);
-int color_parse(const char *value, char *dst);
-int color_parse_mem(const char *value, int len, char *dst);
+/*
+ * Parse a config option, which can be a boolean or one of
+ * "never", "auto", "always". Return a constant of
+ * GIT_COLOR_NEVER for "never" or negative boolean,
+ * GIT_COLOR_ALWAYS for "always" or a positive boolean,
+ * and GIT_COLOR_AUTO for "auto".
+ */
+extern int git_config_colorbool(const char *var, const char *value);
+
+/*
+ * Resolve the constants as returned by git_config_colorbool()
+ * (specifically "auto") to a boolean answer.
+ */
+extern int want_color(int var);
+
+/*
+ * Translate a Git color from 'value' into a string that the terminal can
+ * interpret and store it into 'dst'. The Git color values are of the form
+ * "foreground [background] [attr]" where fore- and background can be a color
+ * name ("red"), a RGB code (#0xFF) or a 256-color-mode from the terminal.
+ */
+extern int color_parse(const char *value, char *dst);
+extern int color_parse_mem(const char *value, int len, char *dst);
+
+/*
+ * Output the formatted string in the specified color (and then reset to normal
+ * color so subsequent output is uncolored). Omits the color encapsulation if
+ * `color` is NULL. The `color_fprintf_ln` prints a new line after resetting
+ * the color. The `color_print_strbuf` prints the given pre-formatted strbuf
+ * instead, up to its first NUL character.
+ */
 __attribute__((format (printf, 3, 4)))
-int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
+extern int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
 __attribute__((format (printf, 3, 4)))
-int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
-void color_print_strbuf(FILE *fp, const char *color, const struct strbuf *sb);
+extern int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
+extern void color_print_strbuf(FILE *fp, const char *color, const struct 
strbuf *sb);
 
-int color_is_nil(const char *color);
+/*
+ * Check if the given color is GIT_COLOR_NIL that means "no color selected".
+ * The caller needs to replace the color with the actual desired color.
+ */
+extern int color_is_nil(const char *color);
 
 #endif /* COLOR_H */
-- 
2.16.0.rc0.223.g4a4ac83678-goog