Lexer and parser for advanced calculator (Flex + bison)

It is necessary to develop the application in C or C ++ programming language, using tools for developing lexers and parsers, which works as an advanced calculator. Calculator calculates mathematical expressions line by line, while having the ability to store in variables and calls of trigonometric functions. Calculator description: • The print command is used to print the value of an expression. • The types of data that can appear in expressions are strings and real numbers, • operations that can be performed with real numbers are addition, subtraction less, multiplication and division (+, -, *, /) respecting the priority of multiplication and divisions over the other two, • It is possible to group expressions using pairs of parentheses (), [] and {} which are they do not differ in functionality, but contribute to clarity expression : a = 56*([5 + 4.7 * (6-2/3) - 8.875] + 5.87) print a 1515.453333 • there is an unary operator -, which denies the value of the expression. print 10 + 20 20.000000 print -10 + 20 10.000000 print ---10 -10.000000 • The operation that can be performed with strings is the build, which it uses operator &, • If a string and expression are found in the operation, the expression must be evaluated and converted him into his textual representation, print "Temperature is" & 20 & "degrees The temperature is 20.000000 degrees print "Temperature is" & (20 * 9/5 + 32) & "Fahrenheit" The temperature is 68.000000 Fahrenheit • It is possible to use the functions of one argument sin, cos, sindeg and cosdeg which calculate the sine and cosine of the angle in radians, ie degrees. Functions can be used with or without parentheses around the argument, eg sin (0.456) and sin 0.456 are equivalent. When calling with parentheses, you may not specify an expression inside parentheses. If we omit the brackets, only the number can be passed or a variable as a parameter, not an entire expression. print sin(90) 0.893997 print sindeg 90 1.000000 print sindeg(3*30) 1.000000 To remember the results of arithmetic expressions, as well as to use these values in other expressions, variables of arbitrary name may be used (rule naming as in C language). The variables are exclusively of the real number type. It's not it is possible to store a string in a variable. • Variables are assigned a value by the operator =. • An assignment operation is also an arithmetic expression whose value is exactly assigned value so that it is possible to write an expression that variables b assigns a value of 3 and then assigns the same value to variable A: foo_ = bar1 = 3 print foo_ 3.000000 print bar1 3.000000 • The print command can also be used to print multiple values ​​(expressions), where values ​​(expressions) are separated by commas (eg print var, 4, 5/10). Each comma-separated value is printed in a new line on the standard exit. print foo_ + 5, "bar = " & bar1, 10.0 8.000000 bar = 3.000000 10.000000 The calculator takes all commands from the standard input. Anything that is not precisely specified fictional or cannot be inferred from the example below, you can realize it arbitrarily, but not to violate any of the above. The implemented task should contain a Makefile that compiles the program uses the make command and generates an executable file named calculator.