Some work

src/memory.c

@@ -36,3 +36,69 @@ void *lisp_aligned_alloc(size_t alignment, size_t size) {
     }
     return ptr;
 }
+
+#define STRING_STREAM_BLOCK_SIZE 32
+static void ensure_string_stream_space(StringStream *restrict stream,
+                                       size_t space) {
+    size_t min_size = stream->nchars + space;
+    size_t new_size = stream->size;
+    while (new_size < min_size) {
+        new_size += STRING_STREAM_BLOCK_SIZE;
+    }
+    if (new_size != stream->size) {
+        stream->buffer = lisp_realloc(stream->buffer, new_size + 1);
+    }
+}
+
+int string_stream_printf(StringStream *restrict stream,
+                         const char *restrict format, ...) {
+    va_list args;
+    va_start(args, format);
+    int rval = string_stream_vprintf(stream, format, args);
+    va_end(args);
+    return rval;
+}
+
+int string_stream_vprintf(StringStream *restrict stream,
+                          const char *restrict format, va_list args) {
+    va_list args_copy;
+    va_copy(args_copy, args);
+    int space = vsnprintf(NULL, 0, format, args_copy);
+    if (space < 0) {
+        abort();
+    }
+    va_end(args_copy);
+    ensure_string_stream_space(stream, space);
+    int rval = vsnprintf(stream->buffer + stream->nchars,
+                         stream->size + 1 - stream->nchars, format, args);
+    if (rval < 0) {
+        abort();
+    }
+    stream->nchars += rval;
+    return rval;
+}
+
+bool strgetline(const char *restrict buf, size_t buf_length,
+                const char **restrict start, size_t *restrict length) {
+    if (!*start) {
+        *start = buf;
+        if (!buf_length) {
+            *length = 0;
+            return true;
+        }
+    } else if (!buf_length) {
+        return false;
+    } else if (*start + *length >= buf + buf_length - 1) {
+        return false;
+    } else /* if (*start) */ {
+        *start += *length + 1;
+    }
+    size_t left = buf_length - (*start - buf);
+    char *found;
+    if ((found = memchr(*start, '\n', left))) {
+        *length = found - *start;
+    } else {
+        *length = left;
+    }
+    return true;
+}