fix e-notation and negative numbers literals; add unit test for e-notation (#182)

Author: kkozik-amplify

hcl2/hcl2.lark

@@ -61,11 +61,12 @@ STRING_CHARS : /(?:(?!\${)([^"\\]|\\.))+/ // any character except '"'
 string_with_interpolation: "\"" (STRING_CHARS)* interpolation_maybe_nested (STRING_CHARS | interpolation_maybe_nested)* "\""
 interpolation_maybe_nested: "${" expression "}"
 
-int_lit : DECIMAL+
-!float_lit: DECIMAL+ "." DECIMAL+ (EXP_MARK DECIMAL+)?
-            | DECIMAL+ ("." DECIMAL+)? EXP_MARK DECIMAL+
+int_lit : NEGATIVE_DECIMAL? DECIMAL+ | NEGATIVE_DECIMAL+
+!float_lit: (NEGATIVE_DECIMAL? DECIMAL+ | NEGATIVE_DECIMAL+) "." DECIMAL+ (EXP_MARK)?
+            |  (NEGATIVE_DECIMAL? DECIMAL+ | NEGATIVE_DECIMAL+) ("." DECIMAL+)? (EXP_MARK)
+NEGATIVE_DECIMAL : "-" DECIMAL
 DECIMAL : "0".."9"
-EXP_MARK : ("e" | "E") ("+" | "-")?
+EXP_MARK : ("e" | "E") ("+" | "-")? DECIMAL+
 EQ : /[ \t]*=(?!=|>)/
 
 tuple : "[" (new_line_or_comment* expression new_line_or_comment* ",")* (new_line_or_comment* expression)? new_line_or_comment* "]"

test/unit/test_hcl2_syntax.py

@@ -72,7 +72,7 @@ def test_block_multiple_labels(self):
 
     def test_unary_operation(self):
         operations = [
-            ("identifier = -10", {"identifier": "${-10}"}),
+            ("identifier = -10", {"identifier": -10}),
             ("identifier = !true", {"identifier": "${!true}"}),
         ]
         for hcl, dict_ in operations:
@@ -151,3 +151,16 @@ def test_index(self):
         for call, expected in indexes.items():
             result = self.load_to_dict(call)
             self.assertDictEqual(result, expected)
+
+    def test_e_notation(self):
+        literals = {
+            "var = 3e4": {"var": 30000.0},
+            "var = 3.5e5": {"var": 350000.0},
+            "var = -3e6": {"var": -3e6},
+            "var = -2.3e4": {"var": -2.3e4},
+            "var = -5e-2": {"var": -5e-2},
+            "var = -6.1e-3": {"var": -6.1e-3},
+        }
+        for actual, expected in literals.items():
+            result = self.load_to_dict(actual)
+            self.assertDictEqual(result, expected)