Stack-based arithmetics

src/executor.py

@@ -24,27 +24,27 @@ def execute_block(self, block, bindings: Bindings):
                 return True
 
     def instruction_add(self, args, bindings):
-        value, (_, target) = args
+        ((_, target),) = args
+        current = self.stack.pop()
         old = bindings.resolve(target)
-        current = self.resolve_value(value, bindings)
         bindings.assign(target, old + current)
 
     def instruction_subtract(self, args, bindings):
-        value, (_, target) = args
+        ((_, target),) = args
+        current = self.stack.pop()
         old = bindings.resolve(target)
-        current = self.resolve_value(value, bindings)
         bindings.assign(target, old - current)
 
     def instruction_multiply(self, args, bindings):
-        value, (_, target) = args
+        ((_, target),) = args
+        current = self.stack.pop()
         old = bindings.resolve(target)
-        current = self.resolve_value(value, bindings)
         bindings.assign(target, old * current)
 
     def instruction_divide(self, args, bindings):
-        value, (_, target) = args
+        ((_, target),) = args
+        current = self.stack.pop()
         old = bindings.resolve(target)
-        current = self.resolve_value(value, bindings)
         bindings.assign(target, old // current)
 
     def instruction_and(self, args, bindings):
@@ -139,9 +139,7 @@ def instruction_load(self):
 
         for pos in reversed(temp_positions):
             if pos < 0 or pos >= len(self.heap):
-                raise InvalidMemoryAddressException(
-                    f"Invalid memory access at position: {pos}"
-                )
+                raise InvalidMemoryAddressException(f"Invalid memory access at position: {pos}")
 
             value = self.heap[pos]
             self.stack.append(value)

src/grammar.py

@@ -5,17 +5,15 @@
     program         = ws_0n subroutine (sp_0n br ws_0n subroutine)* ws_0n
     subroutine      = identifier ws_1n block
     block           = begin ws_1n (instruction (sp_0n br ws_0n instruction)*)? ws_1n end
-    instruction     = assignment / conditional / loop / stack_op
-                        / arithmetic_op / boolean_op / io_op / stop / identifier
-                        / halt / store / load
+    instruction     = assignment / conditional / loop / stack / op / io / stop
+                        / identifier / halt / store / load
 
     assignment      = let sp_1n identifier
     conditional     = if sp_1n value ws_1n block (ws_1n elif sp_1n value ws_1n block)* (ws_1n else ws_1n block)?
     loop            = while sp_1n value ws_1n block
-    stack_op        = (push sp_1n value) / (pop sp_1n identifier)
-    arithmetic_op   = (add / subtract / multiply / divide) sp_1n value sp_1n identifier
-    boolean_op      = (and / or / xor / negate / not) sp_1n identifier
-    io_op           = print sp_1n value
+    stack           = (push sp_1n value) / (pop sp_1n identifier)
+    op              = (add / subtract / multiply / divide / and / or / xor / negate / not) sp_1n identifier
+    io              = print sp_1n value
     halt            = exit sp_1n value
 
     value           = identifier / literal
@@ -37,9 +35,8 @@
     sp_1n           = ~r"[ \t]+"
 
     reserved        = begin / end / stop / if / elif / else / while / push
-                        / pop / let / add / subtract / multiply
-                        / divide / and / or / xor / not / print / exit / store
-                        / load
+                        / pop / let / add / subtract / multiply / divide / and
+                        / or / xor / not / print / exit / store / load
     begin           = ~r"begin"i / ~r"do"i
     exit            = ~r"exit"i
     end             = ~r"end"i

src/parser.py

@@ -2,23 +2,23 @@
 import argparse
 import pprint
 
-import grammar as grammar
-import visitor as visitor
-from preprocessor import PipelinePreprocessor, CommentsPreprocessor
+import grammar
+import visitor
+import preprocessor
 
 
 class ImperivmParser:
     def __init__(
         self,
         grammar=grammar.imperivm,
         visitor=visitor.ImperivmVisitor(),
-        preprocessor=None,
+        preprocessor=preprocessor.PipelinePreprocessor(
+            [preprocessor.CommentsPreprocessor()]
+        ),
     ):
         self.grammar = grammar
         self.visitor = visitor
-        self.preprocessor = preprocessor or PipelinePreprocessor(
-            [CommentsPreprocessor()]
-        )
+        self.preprocessor = preprocessor
 
     def parse(self, program):
         program = self.preprocessor.process(program)

src/preprocessor.py

@@ -5,14 +5,16 @@
 
 class Preprocessor(ABC):
     @abstractmethod
-    def process(self, program: str) -> str:
+    def process(self, program: str):
         pass
 
 
 class CommentsPreprocessor(Preprocessor):
     @override
     def process(self, program: str):
-        cleaned_program = map(lambda line: re.sub(r"#.*$", "", line), program.splitlines())
+        cleaned_program = map(
+            lambda line: re.sub(r"#.*$", "", line), program.splitlines()
+        )
         return "\n".join(cleaned_program)
 
 
@@ -24,4 +26,4 @@ def __init__(self, preprocessor_actions: List[Preprocessor]):
     def process(self, program: str):
         for action in self.preprocessor_actions:
             program = action.process(program)
-        return program
+        return program

src/visitor.py

@@ -38,9 +38,7 @@ def visit_assignment(self, _, visited_children):
         return instruction.text, target
 
     def visit_conditional(self, _, visited_children):
-        operation, _, condition, _, block, elif_operations, else_operations = (
-            visited_children
-        )
+        operation, _, condition, _, block, elif_operations, else_operations = visited_children
 
         elif_tree = []
         if type(elif_operations) is list:
@@ -59,20 +57,16 @@ def visit_loop(self, _, visited_children):
         operation, _, condition, _, block = visited_children
         return operation.text, condition, block
 
-    def visit_stack_op(self, _, visited_children):
+    def visit_stack(self, _, visited_children):
         [child] = visited_children
         operation, _, target = child
         return operation.text, target
 
-    def visit_arithmetic_op(self, _, visited_children):
-        [operation], _, value, _, target = visited_children
-        return operation.text, value, target
-
-    def visit_boolean_op(self, _, visited_children):
+    def visit_op(self, _, visited_children):
         [operation], _, target = visited_children
         return operation.text, target
 
-    def visit_io_op(self, _, visited_children):
+    def visit_io(self, _, visited_children):
         operation, _, target = visited_children
         return operation.text, target
 
@@ -103,5 +97,5 @@ def visit_identifier(self, node, _):
         return "id", node.text
 
     def generic_visit(self, node, visited_children):
-        """The generic visit method."""
+        """the generic visit method"""
         return visited_children or node

tests/add.imp

@@ -2,7 +2,8 @@ main
     begin
         push -5
         let x
-        add 5 x
+        push 5
+        add x
         exit x
         exit 1
     end

tests/divide.imp

@@ -2,7 +2,8 @@ main
     begin
         push 0
         let x
-        divide 14884 x
+        push 14884
+        divide x
         exit x
         exit 1
     end

tests/multiply.imp

@@ -2,7 +2,8 @@ main
     begin
         push 84781
         let x
-        multiply 0 x
+        push 0
+        multiply x
         exit x
         exit 1
     end

tests/negate.imp

@@ -3,7 +3,8 @@ main begin
   let x
   negate x
 
-  add 2 x
+  push 2
+  add x
 
   if x do
     exit 1

tests/or.imp

@@ -4,7 +4,8 @@ main begin
   push 2
   or x
 
-  subtract 3 x
+  push 3
+  subtract x
 
   if x do
     exit 1

tests/subtract.imp

@@ -2,7 +2,8 @@ main
     begin
         push 5
         let x
-        subtract 5 x
+        push 5
+        subtract x
         exit x
         exit 1
     end

tests/xor.imp

@@ -4,7 +4,8 @@ main begin
   push 3
   xor x
 
-  subtract 2 x
+  push 2
+  subtract x
 
   if x do
     exit 1