bshell: re-organise build into three separate components

bshell: the front-end binary
bshell.runtime: contains the parser, compiler, and classes needed to run bshell scripts
bshell.core: contains the builtin commandlets and aliases

bshell.runtime/line-source.c

@@ -0,0 +1,39 @@
+#include <bshell/line-source.h>
+
+enum bshell_status bshell_line_source_get_name(
+	struct bshell_line_source *src,
+	char *buf,
+	size_t count,
+	size_t *nr_read)
+{
+	if (src->s_get_name) {
+		return src->s_get_name(src, buf, count, nr_read);
+	}
+
+	return BSHELL_ERR_NOT_SUPPORTED;
+}
+
+enum bshell_status bshell_line_source_readline(
+	struct bshell_line_source *src,
+	fx_stringstream *out)
+{
+	if (src->s_readline) {
+		return src->s_readline(src, out);
+	}
+
+	return BSHELL_ERR_NOT_SUPPORTED;
+}
+
+enum bshell_status bshell_line_source_get_row(
+	struct bshell_line_source *src,
+	size_t row,
+	char *buf,
+	size_t count,
+	size_t *nr_read)
+{
+	if (src->s_get_row) {
+		return src->s_get_row(src, row, buf, count, nr_read);
+	}
+
+	return BSHELL_ERR_NOT_SUPPORTED;
+}