compiler: add support for import/export statements

This commit introduces syntax level support for ES6 style module import
and export statements. Imports are resolved at compile time and the
corresponding module code is compiled into the main program.

Also add testcases to cover import and export statement semantics.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/custom/99_bugs/38_index_segfault b/tests/custom/99_bugs/38_index_segfault
new file mode 100644
index 0000000..e29b99f
--- /dev/null
+++ b/tests/custom/99_bugs/38_index_segfault
@@ -0,0 +1,28 @@
+When index() or rindex() was invoked with a string haystack and a non-
+string needle argument, a segmentation fault occurred due to an internal
+strlen() invocation on a NULL pointer.
+
+-- Testcase --
+print(index("abc", []), "\n")
+-- End --
+
+-- Args --
+-R
+-- End --
+
+-- Expect stdout --
+-1
+-- End --
+
+
+-- Testcase --
+print(rindex("abc", []), "\n")
+-- End --
+
+-- Args --
+-R
+-- End --
+
+-- Expect stdout --
+-1
+-- End --