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, 21 insertions, 0 deletions

diff --git a/tests/custom/99_bugs/25_lexer_shifted_offsets b/tests/custom/99_bugs/25_lexer_shifted_offsets
new file mode 100644
index 0000000..db10121
--- /dev/null
+++ b/tests/custom/99_bugs/25_lexer_shifted_offsets
@@ -0,0 +1,21 @@
+When lexing a source buffer with a non-zero offset, e.g. due to a
+skipped interpreter line, lexical tokens reported a wrong offset
+to the compiler, causing error locations and source context lines
+to be incorrectly shifted.
+
+-- Testcase --
+#!/usr/bin/env ucode
+{%
+	die("Error");
+%}
+-- End --
+
+-- Expect stderr --
+Error
+In line 3, byte 12:
+
+ `    die("Error");`
+  Near here -----^
+
+
+-- End --