frontend: add a line editor for shell input

frontend/line-ed/tty.h

@@ -0,0 +1,140 @@
+#ifndef DARWIN_TTY_H_
+#define DARWIN_TTY_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define S_TTY_CTRL_KEY(c) ((c) | S_MOD_CTRL)
+
+struct s_tty;
+
+#define MAKE_VMODE(fg, bg, a) \
+	{ \
+		.v_fg = fg, \
+		.v_bg = bg, \
+		.v_attrib = (a) \
+	}
+
+#define MAKE_COLOUR_DEFAULT(v) \
+	{ \
+		.c_mode = TTY_COLOUR_NONE, \
+	}
+
+#define MAKE_COLOUR_16(v) \
+	{ \
+		.c_mode = TTY_COLOUR_16, \
+		.c_16 = { \
+			.value = (v) \
+		} \
+	}
+
+#define MAKE_COLOUR_256(v) \
+	{ \
+		.c_mode = TTY_COLOUR_256, \
+		.c_256 = { \
+			.value = (v) \
+		} \
+	}
+
+#define MAKE_COLOUR_TRUE(cr, cg, cb) \
+	{ \
+		.c_mode = TTY_COLOUR_TRUE, \
+		.c_true = { \
+			.r = (cr), \
+			.g = (cg), \
+			.b = (cb) \
+		} \
+	}
+
+typedef uint32_t s_keycode;
+
+/* codepoints U+F0000 to U+FFFFD are reserved areas in Unicode, free for
+ * application use. store special keycodes here */
+enum s_keys {
+	S_KEY_ARROW_LEFT = 0xF0000,
+	S_KEY_ARROW_RIGHT,
+	S_KEY_ARROW_UP,
+	S_KEY_ARROW_DOWN,
+	S_KEY_BACKSPACE,
+	S_KEY_RETURN,
+
+	S_MOD_CTRL = 0x10000000,
+
+	S_KEY_EOF = 0xFFFFFFFF,
+};
+
+enum s_tty_colour16 {
+	TTY_COLOUR16_BLACK = 0,
+	TTY_COLOUR16_RED,
+	TTY_COLOUR16_GREEN,
+	TTY_COLOUR16_YELLOW,
+	TTY_COLOUR16_BLUE,
+	TTY_COLOUR16_MAGENTA,
+	TTY_COLOUR16_CYAN,
+	TTY_COLOUR16_WHITE,
+	TTY_COLOUR16_GREY,
+	TTY_COLOUR16_BRIGHT_RED,
+	TTY_COLOUR16_BRIGHT_GREEN,
+	TTY_COLOUR16_BRIGHT_YELLOW,
+	TTY_COLOUR16_BRIGHT_BLUE,
+	TTY_COLOUR16_BRIGHT_MAGENTA,
+	TTY_COLOUR16_BRIGHT_CYAN,
+	TTY_COLOUR16_BRIGHT_WHITE,
+};
+
+enum s_tty_colour_mode {
+	TTY_COLOUR_NONE = 0,
+	TTY_COLOUR_16,
+	TTY_COLOUR_256,
+	TTY_COLOUR_TRUE,
+};
+
+enum s_tty_attrib {
+	TTY_ATTRIB_NORMAL = 0x00u,
+	TTY_ATTRIB_BOLD = 0x01u,
+	TTY_ATTRIB_UNDERLINE = 0x02u,
+	TTY_ATTRIB_ITALIC = 0x04u,
+};
+
+struct s_tty_colour {
+	enum s_tty_colour_mode c_mode;
+
+	union {
+		struct {
+			uint8_t value;
+		} c_16;
+
+		struct {
+			uint8_t value;
+		} c_256;
+
+		struct {
+			uint8_t r;
+			uint8_t g;
+			uint8_t b;
+		} c_true;
+	};
+};
+
+struct s_tty_vmode {
+	enum s_tty_attrib v_attrib;
+	struct s_tty_colour v_fg;
+	struct s_tty_colour v_bg;
+};
+
+static inline unsigned int s_keycode_get_key(s_keycode v)
+{
+	return v & 0x0FFFFFFF;
+}
+
+extern struct s_tty *s_get_tty(void);
+extern bool s_tty_is_interactive(const struct s_tty *tty);
+
+extern void s_tty_set_raw(struct s_tty *tty);
+extern void s_tty_set_canon(struct s_tty *tty);
+extern void s_tty_reset_vmode(struct s_tty *tty);
+extern void s_tty_set_vmode(struct s_tty *tty, const struct s_tty_vmode *vmode);
+
+extern s_keycode s_tty_read_key(struct s_tty *tty);
+
+#endif