+// test: echo -e 'inc\ninc (\ndec\ndec (' | calc.exe | grep -c error | xargs test 4 =
+// test: echo -e 'inc (11)\ndec (0)' | calc.exe | grep -c invalid | xargs test 2 =
+// test: echo -e 'while (inc (1) < 100, sto (2, rcl (1) + rcl (2)))' | calc.exe | grep -q '=> 5050'
+// test: echo -e 'while\nwhile (inc (1) < 3,\nwhile (inc (1) < 100, sto (2, rcl (1) + rcl (2))' | calc.exe | grep -c error | xargs test 3 =
+// test: echo -e 'while (0, 1)' | calc.exe -v 3 | grep -q While
+// test: echo -e '{sto (1, 1 + 1), rcl (1) * 3}' | calc.exe -v 3 | grep -q 'Program'
+// test: echo -e '{sto (1, 1 + 1), rcl (1) * 3}' | calc.exe | grep -q '=> 6'
+// test: echo -e '{\n{}\n{1, 2\n{sto (1, 1 + 1),\npow(2, {sto (1, 1 + 2), 2}, {rcl(2)})\n2 {sto (1, 1 + 1)}' | calc.exe | grep -c error | xargs test 6 =
+// test: echo -e '1 }\n1 )\n1 , 2\n ' | calc.exe | grep -c error | xargs test 3 =
+// test: echo -e 'print (1)' | calc.exe -v 3 | grep -q Print
+// test: echo -e 'si\t\t (pi / 2)' | calc.exe | grep -q '=> 1'
+// test: echo -e '1 + 1;\nans + 1' | calc.exe | grep -qv 2
+// test: echo -e 'mem (3)\nsto (4, pi)' | calc.exe | grep -q "invalid index"
+// test: echo -e 'sto (2, 3)\nmem (2)\ndisp' | calc.exe | grep -q 'storage: 0 3$'
+// test: echo -e 'disp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'sto (3, 10)\ndisp' | calc.exe | grep -q "storage: 0 0 10 0 0 0 0 0 0 0"
+// test: echo -e 'rcl (3)\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'inc (2)\ndisp' | calc.exe | grep -q "storage: 0 1 0 0 0 0 0 0 0 0"
+// test: echo -e 'dec (2)\ndisp' | calc.exe | grep -q "storage: 0 -1 0 0 0 0 0 0 0 0"
+// test: echo -e 'sto (3, pi)\nclr\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'mem (3)\nclr' | calc.exe -v 3 | grep -q Clear
+
+// Gauss sequence
+// test: echo -e '{sto (1, 0), sto (10, 0), while (inc (10) < 100, {sto (1, rcl (1) + rcl (10)), print (rcl (1))})};' | calc.exe | grep -q '=> 5050'
+
+// Fibonacci sequence
+// test: echo -e '{sto (1, 1), sto (2, 1), sto (10, 1), while (inc (10) < 12 - 1, {sto (3, rcl (1) + rcl (2)), sto (1, rcl (2)), print (sto (2, rcl (3)))})};' | calc.exe | grep -q '=> 144'
+
+// Gold number
+// test: echo -e '{sto (1, 1), sto (2, 1), sto (10, 1), while (inc (10) < 15 - 1, {sto (3, rcl (1) + rcl (2)), sto (1, rcl (2)), print (sto (2, rcl (3)) / rcl (1))})};' | calc.exe | grep -q '=> 1.61803'