Added variable

README.md

@@ -74,7 +74,9 @@ additional_functions = {
 }
 ```
 
-The `sy.compute` (and `sy.shuting_yard`) also have a `case_sensitive` parameter (bool, default is `True`).
+The `sy.compute` (and `sy.shuting_yard`) also have extra parameters :
+ - `case_sensitive` (bool, defaults to `True`) : if `True`, will consider `sin` and `SIN` different functions.
+ - `variable` (str, optional) : if defined, will consider any token matching it as a number. This is useful in expression such as `min(x, 1)` to get `x` to behave as a number.
 
 ## Additional features
 

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
 	name="shunting-yard",
-	version="1.0.4",
+	version="1.0.5",
 	author="Paul 'charon25' Kern",
 	description="Compute any math expression",
 	long_description=long_description,
@@ -14,5 +14,5 @@
 	url="https://www.github.com/charon25/ShuntingYard",
 	license="MIT",
 	packages=['shunting_yard'],
-	download_url="https://github.com/charon25/ShuntingYard/archive/refs/tags/v1.0.4.tar.gz"
+	download_url="https://github.com/charon25/ShuntingYard/archive/refs/tags/v1.0.5.tar.gz"
 )

shunting_yard/shunting_yard.py

@@ -1,6 +1,7 @@
 from string import ascii_lowercase
 import math
 from enum import Enum
+from typing import Optional
 
 from shunting_yard.tokenize import tokenize
 from shunting_yard.constants import BASE_OPERATORS, NUMBER_CHARS, FUNCTION_CHARS, UNARY_OPERATORS_SYMBOLS
@@ -42,7 +43,7 @@ class Associativity(Enum):
 
 
 # Reference : https://en.wikipedia.org/wiki/Shunting_yard_algorithm
-def shunting_yard(expression: str, case_sensitive: bool = True) -> str:
+def shunting_yard(expression: str, case_sensitive: bool = True, variable: Optional[str] = None) -> str:
     """Convert the given classical math expression into Reverse Polish Notation using the Shunting-yard algorithm (see https://en.wikipedia.org/wiki/Shunting_yard_algorithm for more details). All whitespace are ignored.
 
 
@@ -56,6 +57,7 @@ def shunting_yard(expression: str, case_sensitive: bool = True) -> str:
     Args:
         expression (str): string containing the mathematical expression to convert.
         case_sensitive (bool): indicates whether the expression should care about case.
+        variable (str, optional): if defined, will treat every token matching the variable as a number.
 
     Raises:
         MismatchedBracketsError: raised if the bracket are unbalanced.
@@ -73,7 +75,7 @@ def shunting_yard(expression: str, case_sensitive: bool = True) -> str:
     for token in tokenize(expression):
         first_char = token[0]
 
-        if first_char in NUMBER_CHARS:
+        if first_char in NUMBER_CHARS or token == variable:
             output.append(token)
             if len(operator_stack) > 0 and operator_stack[-1] in UNARY_OPERATORS_SYMBOLS:
                 output.append(operator_stack.pop())

tests/test_shunting_yard.py

@@ -54,6 +54,13 @@ def test_unary_in_function(self):
         self.assertEqual(shunting_yard('min(1, -(2+3))'), '1 2 3 + -u min')
         self.assertEqual(shunting_yard('min(1, -min(3, 4))'), '1 3 4 min -u min')
 
+    def test_variable(self):
+        self.assertEqual(shunting_yard('min(x, 1)'), '1 x min')
+        self.assertEqual(shunting_yard('min(x, 1)', variable='x'), 'x 1 min')
+        self.assertEqual(shunting_yard('min(1, x)', variable='x'), '1 x min')
+        self.assertEqual(shunting_yard('min(ab, 1)', variable='ab'), 'ab 1 min')
+        self.assertEqual(shunting_yard('min(1, x, 2)', variable='x'), '1 x 2 min')
+
 
 if __name__ == '__main__':
     unittest.main()