From 8fa2e4830e5da96f4ee8190f309710618fd95906 Mon Sep 17 00:00:00 2001
From: "Johan B.W. de Vries" <info@jbwdevries.nl>
Date: Tue, 14 Nov 2023 14:09:17 +0100
Subject: [PATCH] Support negative literals

---
 phasm/parser.py                               | 31 +++++++++++++++++++
 phasm/wasmgenerator.py                        |  2 +-
 .../generator_tuple_all_primitives.json       |  4 +--
 .../integration/test_lang/test_primitives.py  | 26 ----------------
 4 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/phasm/parser.py b/phasm/parser.py
index e3799ab..fc1d28f 100644
--- a/phasm/parser.py
+++ b/phasm/parser.py
@@ -39,11 +39,39 @@ def phasm_parse(source: str) -> Module:
     """
     res = ast.parse(source, '')
 
+    res = OptimizerTransformer().visit(res)
+
     our_visitor = OurVisitor()
     return our_visitor.visit_Module(res)
 
 OurLocals = Dict[str, Union[FunctionParam]] # FIXME: Does it become easier if we add ModuleConstantDef to this dict?
 
+class OptimizerTransformer(ast.NodeTransformer):
+    """
+    This class optimizes the Python AST, to prepare it for parsing
+    by the OurVisitor class below.
+    """
+    def visit_UnaryOp(self, node: ast.UnaryOp) -> Union[ast.UnaryOp, ast.Constant]:
+        """
+        UnaryOp optimizations
+
+        In the given example:
+        ```py
+        x = -4
+        ```
+        Python will parse it as a unary minus operation on the constant four.
+        For Phasm purposes, this counts as a literal -4.
+        """
+        if (
+                isinstance(node.op, (ast.UAdd, ast.USub, ))
+                and isinstance(node.operand, ast.Constant)
+                and isinstance(node.operand.value, (int, float, ))
+            ):
+            if isinstance(node.op, ast.USub):
+                node.operand.value = -node.operand.value
+            return node.operand
+        return node
+
 class OurVisitor:
     """
     Class to visit a Python syntax tree and create an ourlang syntax tree
@@ -52,6 +80,9 @@ class OurVisitor:
 
     At some point, we may deviate from Python syntax. If nothing else,
     we probably won't keep up with the Python syntax changes.
+
+    See OptimizerTransformer for the changes we make after the Python
+    parsing is done but before the phasm parsing is done.
     """
 
     # pylint: disable=C0103,C0116,C0301,R0201,R0912
diff --git a/phasm/wasmgenerator.py b/phasm/wasmgenerator.py
index 48cca1a..379ee73 100644
--- a/phasm/wasmgenerator.py
+++ b/phasm/wasmgenerator.py
@@ -45,7 +45,7 @@ class Generator_i32i64:
         self.store = functools.partial(self.generator.add_statement, f'{prefix}.store')
 
     def const(self, value: int, comment: Optional[str] = None) -> None:
-        self.generator.add_statement(f'{self.prefix}.const', f'0x{value:08x}', comment=comment)
+        self.generator.add_statement(f'{self.prefix}.const', f'{value}', comment=comment)
 
 class Generator_i32(Generator_i32i64):
     def __init__(self, generator: 'Generator') -> None:
diff --git a/tests/integration/test_lang/generator_tuple_all_primitives.json b/tests/integration/test_lang/generator_tuple_all_primitives.json
index 94785ff..e391d9b 100644
--- a/tests/integration/test_lang/generator_tuple_all_primitives.json
+++ b/tests/integration/test_lang/generator_tuple_all_primitives.json
@@ -1,5 +1,5 @@
 {
 	"TYPE_NAME": "tuple_all_primitives",
-	"TYPE": "(u8, u32, u64, i8, i32, i64, f32, f64, bytes, )",
-	"VAL0": "(1, 4, 8, 1, 4, 8, 125.125, 5000.5, b'Hello, world!', )"
+	"TYPE": "(u8, u32, u64, i8, i8, i32, i32, i64, i64, f32, f32, f64, f64, bytes, )",
+	"VAL0": "(1, 4, 8, 1, -1, 4, -4, 8, -8, 125.125, -125.125, 5000.5, -5000.5, b'Hello, world!', )"
 }
diff --git a/tests/integration/test_lang/test_primitives.py b/tests/integration/test_lang/test_primitives.py
index 96b5ad2..6458d77 100644
--- a/tests/integration/test_lang/test_primitives.py
+++ b/tests/integration/test_lang/test_primitives.py
@@ -267,32 +267,6 @@ def testEntry() -> {type_}:
     assert 5 == result.returned_value
     assert TYPE_MAP[type_] == type(result.returned_value)
 
-@pytest.mark.integration_test
-@pytest.mark.skip('TODO')
-def test_explicit_positive_number():
-    code_py = """
-@exported
-def testEntry() -> i32:
-    return +523
-"""
-
-    result = Suite(code_py).run_code()
-
-    assert 523 == result.returned_value
-
-@pytest.mark.integration_test
-@pytest.mark.skip('TODO')
-def test_explicit_negative_number():
-    code_py = """
-@exported
-def testEntry() -> i32:
-    return -19
-"""
-
-    result = Suite(code_py).run_code()
-
-    assert -19 == result.returned_value
-
 @pytest.mark.integration_test
 def test_call_pre_defined():
     code_py = """