Added implicit multiplication support

README.md

@@ -54,7 +54,7 @@ print(sy.compute("2^32 - sqrt(tan(42))"))
 By default, the module can process the 5 basic operations (`+`, `-`, `*`, `/`, `^`) as well as those functions :
  - sqrt
  - sin, cos, tan
- - min, max (with 2 arguments)
+ - min, max (with 2, 3 or 4 arguments)
  - abs
 
 As well as the constants `pi` and `e`.
@@ -80,6 +80,16 @@ The `sy.compute` (and `sy.shuting_yard`) also have extra parameters :
 
 ## Additional features
 
+### Implicit multiplication
+
+This program supports implicit multiplication (when the `*` symbol is omitted). They can have multiple forms, such as :
+- `(1+2)(2+3)`
+- `2sin(pi)`
+- `(1+2)3`
+- `sin(pi)10`
+
+### Functions
+
 Instead of just calling the `sy.compute` function, you can break it into its parts :
  - `sy.shunting_yard` will return the RPN equivalent expression of the given mathematical expression ;
  - `sy.compute_rpn` will use this expression and compute its value (use the `additional_functions` parameters here).

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
 	name="shunting-yard",
-	version="1.0.7",
+	version="1.0.8",
 	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/v1.0.7.tar.gz"
+	download_url="https://github.com/charon25/ShuntingYard/archive/refs/tags/v1.0.8.tar.gz"
 )

shunting_yard/rpn.py

@@ -1,6 +1,6 @@
-import math
 from operator import add, mul, neg, pos, sub, truediv
 from typing import Any, Callable, Optional, Union
+import math
 
 from shunting_yard.constants import NUMBER_CHARS
 

shunting_yard/shunting_yard.py

@@ -1,7 +1,7 @@
-from string import ascii_lowercase
-import math
 from enum import Enum
 from typing import Optional
+import math
+import re
 
 from shunting_yard.tokenize import tokenize
 from shunting_yard.constants import BASE_OPERATORS, NUMBER_CHARS, FUNCTION_CHARS, SEPARATORS, SEPARATORS_NO_CLOSING_BRACKET, UNARY_OPERATORS_SYMBOLS

shunting_yard/tokenize.py

@@ -1,14 +1,36 @@
+import re
 from typing import Iterator
 
 from shunting_yard.constants import BASE_OPERATORS, FUNCTION_CHARS, FUNCTION_FIRST_CHARS, NUMBER_CHARS, SEPARATORS, UNARY_OPERATORS
 
 
+
+def _remove_implicit_multiplication(expression: str) -> str:
+    """Add '*' to every implicit multiplication. These can be :
+        - between a number and a variable or function: 2x 3sin(x)
+        - between brackets: (x+1)(x-1), sin(x)(1+2)
+        - between a closing bracket and a number/variable/function: sin(x)2, (1+2)x, (1+2)sin(x)
+    However, a lot of cases do not require implicit multiplication, such as:
+        - 0.5
+        - min(1,2)
+        - min((1+2),2)
+        ...
+    """
+
+    # Insert '*' between a number and anything other than a digit, an operation, a closing bracket, a decimal dot, a function parameters separator
+    expression = re.sub(r'\b(\d+)([^)\d.,;+*\/^-])', r'\1*\2', expression)
+    # Insert '*' between a closing bracket and anything other than an operation, another closing bracket, a function parameters separator
+    expression = re.sub(r'(\))([^),;+*\/^-])', r'\1*\2', expression)
+    return expression
+
+
 def tokenize(string: str) -> Iterator[str]:
     if string == '':
         return
 
     # Remove all whitespaces are they do not change anything
     string = ''.join(string.split())
+    string = _remove_implicit_multiplication(string)
 
     cursor = 0
     is_infix = False

tests/test_tokenize.py

@@ -1,6 +1,7 @@
 import unittest
 
 from shunting_yard import tokenize
+from shunting_yard.tokenize import _remove_implicit_multiplication
 
 
 class TestTokenizer(unittest.TestCase):
@@ -73,6 +74,54 @@ def test_digits_in_function_name(self):
         self.assertListEqual(list(tokenize('min3(1, 2)')), ['min3', '(', '1', ',', '2', ')'])
 
 
+class TestRemoveImplicitMultiplication(unittest.TestCase):
+
+    def test_no_implicit_mult(self):
+        self.assertEqual(_remove_implicit_multiplication('1+1'), '1+1')
+        self.assertEqual(_remove_implicit_multiplication('1-1'), '1-1')
+        self.assertEqual(_remove_implicit_multiplication('1*1'), '1*1')
+        self.assertEqual(_remove_implicit_multiplication('1/1'), '1/1')
+        self.assertEqual(_remove_implicit_multiplication('1^1'), '1^1')
+        self.assertEqual(_remove_implicit_multiplication('(1)+1'), '(1)+1')
+        self.assertEqual(_remove_implicit_multiplication('(1)-1'), '(1)-1')
+        self.assertEqual(_remove_implicit_multiplication('(1)*1'), '(1)*1')
+        self.assertEqual(_remove_implicit_multiplication('(1)/1'), '(1)/1')
+        self.assertEqual(_remove_implicit_multiplication('(1)^1'), '(1)^1')
+        self.assertEqual(_remove_implicit_multiplication('((1))'), '((1))')
+
+    def test_no_implicit_mult2(self):
+        self.assertEqual(_remove_implicit_multiplication('0.5'), '0.5')
+        self.assertEqual(_remove_implicit_multiplication('max(1,2)'), 'max(1,2)')
+        self.assertEqual(_remove_implicit_multiplication('max(1;2)'), 'max(1;2)')
+        self.assertEqual(_remove_implicit_multiplication('max((1+2),2)'), 'max((1+2),2)')
+        self.assertEqual(_remove_implicit_multiplication('max((1+2);2)'), 'max((1+2);2)')
+
+    def test_digit_other(self):
+        self.assertEqual(_remove_implicit_multiplication('2x'), '2*x')
+        self.assertEqual(_remove_implicit_multiplication('3cos(5)'), '3*cos(5)')
+        self.assertEqual(_remove_implicit_multiplication('3_func(0)'), '3*_func(0)')
+        self.assertEqual(_remove_implicit_multiplication('1(2+3)'), '1*(2+3)')
+
+    def test_implicit_mult_double_brackets(self):
+        self.assertEqual(_remove_implicit_multiplication('(1+2)(3+4)'), '(1+2)*(3+4)')
+        self.assertEqual(_remove_implicit_multiplication('(1+(2))((3+5)+4)((6+7)(8+9))'), '(1+(2))*((3+5)+4)*((6+7)*(8+9))')
+        self.assertEqual(_remove_implicit_multiplication('sin(pi)(1+2)'), 'sin(pi)*(1+2)')
+
+    def test_implicit_mult_bracket_other(self):
+        self.assertEqual(_remove_implicit_multiplication('sin(1)2'), 'sin(1)*2')
+        self.assertEqual(_remove_implicit_multiplication('sin(1).5'), 'sin(1)*.5')
+        self.assertEqual(_remove_implicit_multiplication('(1+2)3'), '(1+2)*3')
+        self.assertEqual(_remove_implicit_multiplication('(1+2)x'), '(1+2)*x')
+        self.assertEqual(_remove_implicit_multiplication('(1+2)sin(1)'), '(1+2)*sin(1)')
+
+    def test_with_longer_numbers(self):
+        self.assertEqual(_remove_implicit_multiplication('200x'), '200*x')
+        self.assertEqual(_remove_implicit_multiplication('301cos(5)'), '301*cos(5)')
+        self.assertEqual(_remove_implicit_multiplication('345_func(0)'), '345*_func(0)')
+        self.assertEqual(_remove_implicit_multiplication('156(2+3)'), '156*(2+3)')
+        self.assertEqual(_remove_implicit_multiplication('1+200x'), '1+200*x')
+
+
 
 if __name__ == '__main__':
     unittest.main()