• Development platform: Win11 amd64
• Setup:
  In the workspace folder

make

The executable can be found at ./bin/SIC

• Features:
  • Dynamic types
  • Script mode & Calculator mode
  • Support while loop and if command
  • Support functions
  • Support comments
  • Support variables
  • Support () and <SPACE> in expression calculation
  • Error Handling: indicate where a syntax error or a calculation error occurs.
• Grammar:
  • To define or assign a variable, use keyword "let" at the beginning of a line.
  • To define a function, use keyword "def" at the beginning of a line, and add keyword "enddef" after the definition.
  • To define or call a function, demonstrate its parameter/argument list with [] instead of ().
  • To use a while loop, put the loop condition right after the keyword "while" without (), and add keyword "endwhile" after the loop body to demonstrate that the loop is ended.
  • To use a if command, put the condition right after the keyword "if" without (), and add keyword "endif" to demonstrate that the body is ended.
  • To output a value of a variable or an instant expression, use keyword "print" and put the output content after it.
  • To add a comment which will be ignored by the interpreter, put character '#' at the beginning of a line.
  • Operators:
    • + for add
    • - for subtraction and negative mark
    • * for multiplication
    • / for division
    • // for integer division in C++
    • % for modulo
    • ^ for exponential operation
    • = for assignment
    • == for equal comparison
    • != for not equal comparison
    • > for greater than comparison
    • < for less than comparison
    • >= for grater than or equal to comparison
    • <= for less than or equal to comparison
  • Arithmetical priority: Listing from high to low:
    • negative mark
    • ^ exponential operator
    • * / // % multiplication relevant operator
    • + - add and subtraction operator
    • == != > < >= <= comparison operator
    • = assignment operator
• Modes:
  • Script mode:
    • Activated when passed a script file as an argument in the terminal.
    • Exit when the script finishes or a syntax error occurs.
  • Calculator mode:
    • Activated when no file is assigned.
    • Receive input from terminal as expression, and print the result instantly.
    • Keep running after catching exceptions.
    • Exit when receive EOF.

# Script mode:
bin/SIC script_test.sic

# Calculator mode:
bin/SIC

• Examples: All test examples can be found in ./test
  script_test.sic

# variable definition & assignment
let x = 1
let x = x+1

# print
print x * (2+1)
# Output: 6

# while loop
let f_i = 1
let f_i_1 = 1
let i = 2
let n = 40
while i < n
    let f_i = f_i + f_i_1
    let f_i_1 = f_i - f_i_1
    let i = i + 1
    # Fibonacci sequence
endwhile
print f_i
# Output: 102334155

# if
if i == 40
    print 40
    # Output: 40
endif

# function
def Fibonacci[n]
    if n == 1
        return 1
    endif
    if n == 2
        return 1
    endif
    let x = n-1
    let y = n-2
    return Fibonacci[x] + Fibonacci[y]
enddef
print Fibonacci[10]
# Output: 55

calculator_test.in

1
-2 +3
(1-9)*8
2+6/5
0.1+0.2
5//2
5 % 2
2^3
2^3.3
-1.1^3
1 == 1
1 > 1
1<=1
1 != 1
1+
(2+3
()))20+2
1/0
1//0
-1.1^1.1

hello world

calculator_test.ans

1
1
-64
3.200000
0.300000
2
1
8.000000
9.849155
-1.331000
1
0
1
0
Expected digit, got: "", at 2
Lacking right parenthesis
Extra right parenthesis
inf
Divided by 0!
nan

Expected digit, got: "h", at 0

• Unsupported yet:
  • Processing string type.
  • Handling expressions as function arguments.
  • Chinese characters. This also may cause exception report to be ineffective in Calculator mode.
  • Add negative mark to an expression

# error examples:

print "Hello World!"
# error!

def add[a, b]
    return a+b
enddef

print add[1+1, 1]
# error, but you can do this by:
let x = 1+1
print add[x, 1]

let 变量 = 1
print 变量
# error

print -(1+1)
# error, but you can do this by:
print -1 * (1+1)