Semistack

Semistack is an Esoteric programming language designed by PSTF for all beginners of stack structure.

It has a stack, and it will be Turing-complete.

Overview of Semistack

Semistack doesn't ignore case, so every command should all in lowercase(or be parsed as variable name).

Command table(originals)

>> Control flow
for                | For every item in a("stack" for the stack), execute the code b.
while              | While the expression a is true, execute the code b.
if                 | Same as "while", but only execute the code b for once.
else               | Used for construct if-else structure.
elif               | Used for construct if-elif-else structure.
break              | Quit the loop immediately. If it is in Main program, exit immediately.
continue           | Jump to next round of loop. If it is in Main program, do nothing.
>> Stack operation
push               | Push the specified value onto the stack. If nothing detect, duplicate the ToS.
pop                | Pop the ToS.
__tos              | Self-explanatory.
__2ttos            | 2nd-to-top of stack.
>> Arithmetics
add                | Add two values together. You can also use +.
subtract           | Subtract y from x. Alt: -.
multiply           | Multiply x with y. Alt: *.
divide             | Divide x by y, result in float. Alt: /.
intdiv             | Divide x by y, result in quotient. Alt: //.
modulo             | Modulo x by y. Alt: %.
exponent           | Return x^y. Alt: ^.
negate             | Negate the specified value. Reverse if it is string or an array.
range              | Python "range(A,B,C)". Returns an array.
nroot              | Return x^(1/y). Alt: `.
log                | Returns the logarithm of y with x as the base.
>> Variables
let                | Let x to be y. If x doesn't exist, create a variable called x(with the type of y).
===>
    num            | Numbers.
    string         | A string of characters.
    array          | An array.
    bool           | A boolean.
    pair           | A pair of value.
    none           | Nonetype.
>> Pair operations
former             | Former value of a pair.
latter             | Latter value of a pair.
>> Array operations
insert             | Insert x at the index of y. Leave y blank means the tail.
delete             | Delete the element at the index of x.
popdel             | Delete the element at the index of x, but store it at y.
>> I/O
input              | Raw input, with the prompt x.
read               | Parsed input, with the prompt x.
print              | Print the value of x directly.
output             | Output a serie of value, including seperators and a terminator.
>> Libraries
import             | Import a specified library.
>> Miscallenous
random             | A random float between 0 and 1.
randint            | A random integer in the range you've specified.
choice             | Choose an item randomly from an array.
sort               | Sort the array immediately.
and                | Logical AND.
or                 | Logical OR.
not                | Logical NOT.
xor                | Logical XOR.
>> Constants
true, false, empty, nan, infinity

Strings can be written in double quotes. Use backslash for escape(\q is used for double quotes.). Comments are written between parentheses.