stmhal: Add more escape seqs; add debugging output for escape seq.

stmhal/readline.c

+#include <stdio.h>
 #include <string.h>
 
 #include <stm32f4xx_hal.h>
@@ -11,11 +12,18 @@
 #include "readline.h"
 #include "usb.h"
 
+#if 0 // print debugging info
+#define DEBUG_PRINT (1)
+#define DEBUG_printf printf
+#else // don't print debugging info
+#define DEBUG_printf(...) (void)0
+#endif
+
 #define READLINE_HIST_SIZE (8)
 
 static const char *readline_hist[READLINE_HIST_SIZE] = {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL};
 
-enum { ESC_PLAIN = 1, ESC_BRACKET, ESC_BRACKET_DIGIT, ESC_O };
+enum { ESEQ_NONE, ESEQ_ESC, ESEQ_ESC_BRACKET, ESEQ_ESC_BRACKET_DIGIT, ESEQ_ESC_O };
 
 void readline_init(void) {
     memset(readline_hist, 0, READLINE_HIST_SIZE * sizeof(const char*));
@@ -32,7 +40,7 @@ STATIC char *str_dup(const char *str) {
 int readline(vstr_t *line, const char *prompt) {
     stdout_tx_str(prompt);
     int orig_line_len = line->len;
-    int escape_seq = 0;
+    int escape_seq = ESEQ_NONE;
     char escape_seq_buf[1] = {0};
     int hist_cur = -1;
     int cursor_pos = orig_line_len;
@@ -42,16 +50,16 @@ int readline(vstr_t *line, const char *prompt) {
         int redraw_step_back = 0;
         bool redraw_from_cursor = false;
         int redraw_step_forward = 0;
-        if (escape_seq == 0) {
+        if (escape_seq == ESEQ_NONE) {
             if (VCP_CHAR_CTRL_A <= c && c <= VCP_CHAR_CTRL_D && vstr_len(line) == orig_line_len) {
                 // control character with empty line
                 return c;
             } else if (c == VCP_CHAR_CTRL_A) {
                 // CTRL-A with non-empty line is go-to-start-of-line
-                redraw_step_back = cursor_pos - orig_line_len;
+                goto home_key;
             } else if (c == VCP_CHAR_CTRL_E) {
                 // CTRL-E is go-to-end-of-line
-                redraw_step_forward = line->len - cursor_pos;
+                goto end_key;
             } else if (c == '\r') {
                 // newline
                 stdout_tx_str("\r\n");
@@ -66,7 +74,7 @@ int readline(vstr_t *line, const char *prompt) {
                 return 0;
             } else if (c == 27) {
                 // escape sequence
-                escape_seq = ESC_PLAIN;
+                escape_seq = ESEQ_ESC;
             } else if (c == 8 || c == 127) {
                 // backspace/delete
                 if (cursor_pos > orig_line_len) {
@@ -82,23 +90,24 @@ int readline(vstr_t *line, const char *prompt) {
                 redraw_from_cursor = true;
                 redraw_step_forward = 1;
             }
-        } else if (escape_seq == ESC_PLAIN) {
+        } else if (escape_seq == ESEQ_ESC) {
             switch (c) {
                 case '[':
-                    escape_seq = ESC_BRACKET;
+                    escape_seq = ESEQ_ESC_BRACKET;
                     break;
                 case 'O':
-                    escape_seq = ESC_O;
+                    escape_seq = ESEQ_ESC_O;
                     break;
                 default:
-                    escape_seq = 0;
+                    DEBUG_printf("(ESC %d)", c);
+                    escape_seq = ESEQ_NONE;
             }
-        } else if (escape_seq == ESC_BRACKET) {
+        } else if (escape_seq == ESEQ_ESC_BRACKET) {
             if ('0' <= c && c <= '9') {
-                escape_seq = ESC_BRACKET_DIGIT;
+                escape_seq = ESEQ_ESC_BRACKET_DIGIT;
                 escape_seq_buf[0] = c;
             } else {
-                escape_seq = 0;
+                escape_seq = ESEQ_NONE;
                 if (c == 'A') {
                     // up arrow
                     if (hist_cur + 1 < READLINE_HIST_SIZE && readline_hist[hist_cur + 1] != NULL) {
@@ -137,9 +146,17 @@ int readline(vstr_t *line, const char *prompt) {
                     if (cursor_pos > orig_line_len) {
                         redraw_step_back = 1;
                     }
+                } else if (c == 'H') {
+                    // home
+                    goto home_key;
+                } else if (c == 'F') {
+                    // end
+                    goto end_key;
+                } else {
+                    DEBUG_printf("(ESC [ %d)", c);
                 }
             }
-        } else if (escape_seq == ESC_BRACKET_DIGIT) {
+        } else if (escape_seq == ESEQ_ESC_BRACKET_DIGIT) {
             if (c == '~') {
                 if (escape_seq_buf[0] == '1' || escape_seq_buf[0] == '7') {
 home_key:
@@ -147,20 +164,25 @@ home_key:
                 } else if (escape_seq_buf[0] == '4' || escape_seq_buf[0] == '8') {
 end_key:
                     redraw_step_forward = line->len - cursor_pos;
+                } else {
+                    DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
                 }
+            } else {
+                DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
             }
-            escape_seq = 0;
-        } else if (escape_seq == ESC_O) {
+            escape_seq = ESEQ_NONE;
+        } else if (escape_seq == ESEQ_ESC_O) {
             switch (c) {
                 case 'H':
                     goto home_key;
                 case 'F':
                     goto end_key;
                 default:
-                    escape_seq = 0;
+                    DEBUG_printf("(ESC O %d)", c);
+                    escape_seq = ESEQ_NONE;
             }
         } else {
-            escape_seq = 0;
+            escape_seq = ESEQ_NONE;
         }
 
         // redraw command prompt, efficiently