treewide: rewrite ucode interpreter

Replace the former AST walking interpreter implementation with a single pass
bytecode compiler and a corresponding virtual machine.

The rewrite lays the groundwork for a couple of improvements with will be
subsequently implemented:

 - Ability to precompile ucode sources into binary byte code
 - Strippable debug information
 - Reduced runtime memory usage

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

6 files changed, 26 insertions, 15 deletions

diff --git a/tests/00_syntax/05_block_nesting b/tests/00_syntax/05_block_nesting
index 7b74adb..fcfd7da 100644
--- a/tests/00_syntax/05_block_nesting
+++ b/tests/00_syntax/05_block_nesting
@@ -8,6 +8,13 @@ In line 2, byte 61:
   Near here --------------------------------------------------^
 
 
+Syntax error: Template blocks may not be nested
+In line 3, byte 61:
+
+ `We may not nest expression blocks into statement blocks: {% {{ 1 + 2 }} %}.`
+  Near here --------------------------------------------------^
+
+
 -- End --
 
 -- Testcase --
diff --git a/tests/00_syntax/13_object_literals b/tests/00_syntax/13_object_literals
index 60c9f32..67dbd6c 100644
--- a/tests/00_syntax/13_object_literals
+++ b/tests/00_syntax/13_object_literals
@@ -48,6 +48,7 @@ either JSON or JavaScript notation.
 	print(another_obj, "\n");
 	print(third_obj, "\n");
 	print(nested_obj, "\n");
+%}
 -- End --
 
 
diff --git a/tests/00_syntax/16_for_loop b/tests/00_syntax/16_for_loop
index 33d1d97..67edc21 100644
--- a/tests/00_syntax/16_for_loop
+++ b/tests/00_syntax/16_for_loop
@@ -218,11 +218,12 @@ Ensure that for-in loop expressions with more than two variables are
 rejected.
 
 -- Expect stderr --
-Syntax error: Invalid for-in expression
-In line 2, byte 14:
+Syntax error: Unexpected token
+Expecting ';'
+In line 2, byte 24:
 
  `    for (let x, y, z in {})`
-  Near here ------^
+  Near here ----------------^
 
 
 -- End --
@@ -238,11 +239,12 @@ In line 2, byte 14:
 Ensure that assignments in for-in loop expressions are rejected.
 
 -- Expect stderr --
-Syntax error: Invalid for-in expression
-In line 2, byte 13:
+Syntax error: Unexpected token
+Expecting ';'
+In line 2, byte 25:
 
  `    for (let x = 1, y in {})`
-  Near here -----^
+  Near here -----------------^
 
 
 -- End --
@@ -259,7 +261,7 @@ Ensure that too short for-in loop expressions are rejected (1/2).
 
 -- Expect stderr --
 Syntax error: Unexpected token
-Expecting ',' or 'in'
+Expecting ';'
 In line 2, byte 12:
 
  `    for (let x)`
@@ -279,11 +281,12 @@ In line 2, byte 12:
 Ensure that too short for-in loop expressions are rejected (2/2).
 
 -- Expect stderr --
-Syntax error: Invalid for-in expression
-In line 2, byte 14:
+Syntax error: Unexpected token
+Expecting ';'
+In line 2, byte 15:
 
  `    for (let x, y)`
-  Near here ------^
+  Near here -------^
 
 
 -- End --
diff --git a/tests/00_syntax/17_while_loop b/tests/00_syntax/17_while_loop
index 4dfaccc..1e68d6b 100644
--- a/tests/00_syntax/17_while_loop
+++ b/tests/00_syntax/17_while_loop
@@ -32,7 +32,7 @@ Iteration 8
 Iteration 9
 
 A counting while-loop using the alternative syntax:
-Iteration null
+Iteration 0
 Iteration 1
 Iteration 2
 Iteration 3
diff --git a/tests/00_syntax/19_arrow_functions b/tests/00_syntax/19_arrow_functions
index 4847d8a..102c527 100644
--- a/tests/00_syntax/19_arrow_functions
+++ b/tests/00_syntax/19_arrow_functions
@@ -108,11 +108,11 @@ subsequent testcase asserts that case.
 
 -- Expect stderr --
 Syntax error: Unexpected token
-Expecting Label
-In line 2, byte 5:
+Expecting ';'
+In line 2, byte 10:
 
  `    (a + 1) => { print("test\n") }`
-         ^-- Near here
+  Near here --^
 
 
 -- End --
diff --git a/tests/00_syntax/21_regex_literals b/tests/00_syntax/21_regex_literals
index 4aef33f..3af53bb 100644
--- a/tests/00_syntax/21_regex_literals
+++ b/tests/00_syntax/21_regex_literals
@@ -35,7 +35,7 @@ Testing invalid flag characters.
 
 -- Expect stderr --
 Syntax error: Unexpected token
-Expecting ',' or ';'
+Expecting ';'
 In line 2, byte 8:
 
  `    /test/x`