StringEvaluation

8 oct 2021

Library "StringEvaluation"
Methods to handle evaluation of strings.

is_comma(char) Check if char is a comma ".".
Parameters:

• char: string, 1 character string.

Returns: bool.

is_op(char) Check if char is a operator.
Parameters:

• char: string, 1 character string.

Returns: bool.

number(char) convert a single char string into valid number.
Parameters:

• char: string, 1 character string.

Returns: float.

operator(op, left, right) operation between left and right values.
Parameters:

• op: string, operator string character.
  
• left: float, left value of operation.
  
• right: float, right value of operation.

operator_precedence(op) level of precedence of operator.
Parameters:

• op: string, operator 1 char string.

Returns: int.

cleanup(_str) Evaluate a string to clean up and retrieve only used chars
Parameters:

• _str: string, arithmetic operations in a string.

Returns: string array, evaluated array.

generate_rpn(tokens) uses Shunting-Yard algorithm to generate a RPN (Reverse Polish notation)
array of strings from a array of strings containing arithmetic notation.
ex:.. '[3 + 4 * 2 / ( 1 - 5 ) ^ 2 ^ 3]' --> '[3 4 2 * 1 5 - 2 3 ^ ^ / +]'
Parameters:

• tokens: string array, array with arithmetic notation.

Returns:

parse_rpn() evaluate a RPN (Reverse Polish notation) array of strings.
ex:.. 3 4 2 * 1 5 - 2 3 ^ ^ / +
| param tokens string array, RPN ordered tokens, ex(['3', '4', '2', '1', '5', '2', '3', '*', '-', '^', '^', '/', '+']).
| Returns float, solution.

eval() evaluate a string with references to a array of arguments.
| param tokens string, arithmetic operations with references to indices in arguments, ex:"0+1*0+2*2+3" arguments[1, 2, 3]
| param arguments float array, arguments.
| Returns float, solution.

25 oct 2021

Notas de prensa

v2
Update: supports boolean operators and float numbers now
Added:
is_op_component(char) Check if char is a operator component.
  Parameters:
    char: string, 1 character string.
  Returns: bool.

is_boolean_op(char) Check if char is a boolean operator.
  Parameters:
    char: string, 1 character string.
  Returns: bool.

is_alpha(char) Check if char is alphabet.
  Parameters:
    char: string, 1 character string.
  Returns: bool.

boolean_operator(op, left, right) boolean operation between left and right values.
  Parameters:
    op: string, operator string character.
    left: float, left value of operation.
    right: float, right value of operation.

boolean_operator_precedence(op) level of precedence of operator.
  Parameters:
    op: string, operator 1 char string.
  Returns: int.

aggregate_words(tokens) Aggregates words, numbers and operators into one.
  Parameters:
    tokens: string array, array with split string into character tokens.
  Returns: string array.

25 oct 2021

Notas de prensa

v3 minor modification to see if it fixes a bug..

25 oct 2021

Notas de prensa

v4 small test to see if i capture the source of a bug..