mkdir build
cd build

cmake ..
cmake --build . --config [Debug|Release]
..\bin\eval.exe

cmake -G"MinGW Makefiles" -DCMAKE_BUILD_TYPE=[Debug|Release] ..
mingw32-make
..\bin\eval.exe

cmake -DCMAKE_BUILD_TYPE=[Debug|Release] ..
make 
../bin/eval

sin(pi / 2) + sqrt(2) ^ gamma(3) - 4 * 5 / sin(-6 - 7 / ln(8)) - 9

[]
[1, 2, 3, 4, 5]
[1 + 2, (3 - 4) / 5, 6]

@(x){x^2}
@(x, y){x + y}
@(x, y, z){[x + y, y + z, z + x]}
@(a){@(x){x + a}}

1 + [2, 3]
[1, 2] + [3, 4]
[3, 4] * 5
[3, 4] / [5, 6]
([1, 2] - 1.5)^2
sin([1, 2, 3, 4])[1]
len([1, 2, 3, 4])

f(x, y) = sqrt(x^2 + y^2)
f(3, 4)
fib(n) = if_else(gt(n, 1), fib(n - 1) + fib(n - 2), 1)

sum_list(l, n) = if_else(gt(n, 0), sum_list(l, n - 1) + l[n - 1], 0)
sum = @(l){sum_list(l, len(l))}
sum([1, 2, 3])
mean(l) = sum(l) / len(l)

Y = @(f){@(g){f(g(g))}(@(g){f(@(y){g(g)(y)})})}
fact_gen = @(f){@(n){if_else(n, n * f(n - 1), 1)}}
fact = Y(fact_gen)
fact(5)

map_n(list, f, n) = if_else(gt(n, 0), assign(map_n(list, f, n - 1), n - 1, f(list[n - 1])), list)
map(list, f) = map_n(list, f, len(list))
map([1, 2, 3, 4, 5], sin)

construct(f, n) = if_else(gt(n, 0), append(construct(f, n - 1), f(n - 1)), [])
construct(fib, 10)

!init: initialize internal function list
!list: display current identifiers
!exit: exit
!ast: print expression AST

ASSIGN -> ident '=' EXPR
ASSIGN_LABMDA -> ident '(' PARAM_LIST ')' '=' EXPR
EXPR -> EXPR_L1

TERM -> decimal | ident | '(' EXPR ')' | LIST | LAMBDA | INDEX | CALL 
LIST -> '[' EXPR_LIST ']'
LAMBDA -> '@' '(' PARAM_LIST ')' '{' EXPR '}'
INDEX -> TERM '[' EXPR ']'
CALL -> TERM '(' EXPR_LIST ')'
PARAM_LIST -> empty | ident {',' ident}
EXPR_LIST -> empty | EXPR {',' EXPR}
EXPR_UNARY -> ['-'] EXPR_L2
EXPR_L1 -> EXPR_UNARY {OPTR_L1 EXPR_UNARY}
EXPR_L2 -> EXPR_L3 {OPTR_L2 EXPR_L3}
EXPR_L3 -> TERM {'^' TERM}
OPTR_L1 -> '+' | '-'
OPTR_L2 -> '*' | '/'

pi
e
ans

sqrt(x)
sin(x)
cos(x)
tan(x)
asin(x)
acos(x)
atan(x)
exp(x)
ln(x)
abs(x)
round(x)
floor(x)
ceil(x)
gamma(x)
erf(x)

len(list)
assign(list, idx, val)
append(list, val)
slice(list, st, ed)
reverse(list)

not(x)
and(x, y)
or(x, y)

eq(x, y)
neq(x, y)
gt(x, y)
lt(x, y)
geq(x, y)
leq(x, y)

if_else(cond, true, false)