Initial commit w/ small readline echo function

2 files changed, 98 insertions, 0 deletions

diff --git a/src/bootstrap/main.c b/src/bootstrap/main.c
new file mode 100755
index 0000000..861c206
--- /dev/null
+++ b/src/bootstrap/main.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+
+#include "shorthand.h"
+
+typedef struct StringView {
+    char *start;
+    size_t n;
+} StringView;
+
+void
+sv_write(StringView sv) {
+    for (size_t i = 0; i < sv.n; i++) {
+        putchar(sv.start[i]);
+    }
+}
+
+StringView
+read_line(void) {
+    #define RL_BUF_SIZE 1024
+    static char readline_buf[RL_BUF_SIZE];
+
+    // Clear buffer.
+    for (size_t i = 0; i < RL_BUF_SIZE; i++) {
+        readline_buf[i] = 0;
+    }
+
+    // Barebones readline implementation.
+    size_t n = 0;
+    char c;
+    while ((c = getchar()) != '\n') {
+        if (c == '\b') {
+            readline_buf[n] = '\0';
+            n--;
+        } else if (((u8)c >= 0x20 && (u8)c <= 0x7F) && n < RL_BUF_SIZE) {
+            readline_buf[n] = c;
+            n++;
+        }
+    }
+
+    return (StringView){.start = (char *)&readline_buf, .n = n};
+}
+
+void
+display(StringView sv) {
+    if (sv.n != 0) {
+        sv_write(sv);
+        printf("\n");
+    }
+}
+
+#define REPL_PROMPT "bdl> "
+
+int
+main(void) {
+    printf("BDL REPL (Press Ctrl-C to exit)\n");
+    while (true) {
+        printf(REPL_PROMPT);
+        display(read_line());
+    }
+    return 0;
+}
diff --git a/src/bootstrap/shorthand.h b/src/bootstrap/shorthand.h
new file mode 100755
index 0000000..6fcb82c
--- /dev/null
+++ b/src/bootstrap/shorthand.h
@@ -0,0 +1,37 @@
+#ifndef SHORTHAND_H
+#define SHORTHAND_H
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+//
+// This simple header just typedefs the basic C define types to a shorter name,
+// loads the quality of life bool macro for _Bool and defines shorthand macros
+// for byte sizes.
+//
+
+typedef uint8_t      u8;
+typedef uint16_t     u16;
+typedef uint32_t     u32;
+typedef uint64_t     u64;
+typedef int8_t       s8;
+typedef int16_t      s16;
+typedef int32_t      s32;
+typedef int64_t      s64;
+typedef volatile u8  vu8;
+typedef volatile u16 vu16;
+typedef volatile u32 vu32;
+typedef volatile u64 vu64;
+typedef volatile s8  vs8;
+typedef volatile s16 vs16;
+typedef volatile s32 vs32;
+typedef volatile s64 vs64;
+
+#define KB(N) ((u64)(N)   * 1024)
+#define MB(N) ((u64)KB(N) * 1024)
+#define GB(N) ((u64)MB(N) * 1024)
+#define TB(N) ((u64)GB(N) * 1024)
+
+#endif // SHORTHAND_H