xbasic 0.3.1

A library that allows adding a scripting language onto your project with ease. This lets your users write their own arbitrary logic.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174

use xbasic::expr::ExprValue;
use xbasic::xbasic::XBasicBuilder;

mod common;

fn test_program_native_functions<T: 'static>(
	functions: Vec<(&'static str, u8, T)>,
	program: &'static str,
	expected: &'static str,
) where
	T: Fn(Vec<ExprValue>, &mut common::TestIO) -> ExprValue,
{
	let tio = common::TestIO::new(expected);

	let mut xbb = XBasicBuilder::new(tio);

	for (name, arity, native_fn) in functions {
		assert!(xbb
			.define_function(name.to_owned(), arity, native_fn)
			.is_ok());
	}

	let mut xb = xbb.build();

	match xb.run(program) {
		Ok(_) => (),
		Err(_) => {
			for error in xb.error_handler.errors {
				println!("{}", error);
			}
			panic!();
		}
	}

	xb.get_io().check();
}

#[test]
fn basic_native_function() {
	test_program_native_functions(
		vec![("test", 0, |_, _: &mut _| ExprValue::Decimal(123.4))],
		"
print test()
    ",
		"123.4\n",
	);
}

#[test]
fn basic_native_function_argument_order() {
	test_program_native_functions(
		vec![("test", 2, |args: Vec<ExprValue>, _: &mut _| {
			ExprValue::Decimal(args[0].clone().into_decimal() / args[1].clone().into_decimal())
		})],
		"
print test(300, 2)
    ",
		"150\n",
	);
}

#[test]
fn wrong_arity() {
	let tio = common::TestIO::new("");

	let mut xbb = XBasicBuilder::new(tio);
	assert!(xbb
		.define_function("arity".to_string(), 2, |_, _| ExprValue::Decimal(0.0))
		.is_ok(),);
	let mut xb = xbb.build();
	assert!(xb
		.run(
			"
arity(1, 2, 3)
	"
		)
		.is_err());
	assert!(xb.error_handler.had_errors);
	assert_eq!(
		xb.error_handler.errors,
		["[line 2] Error at 'arity': Expected 2 arguments, got 3."]
	);

	xb.get_io().check();
}

#[test]
fn duplicate_native_function() {
	let tio = common::TestIO::new("");

	let mut xbb = XBasicBuilder::new(tio);
	assert!(xbb
		.define_function("arity".to_string(), 2, |_, _| ExprValue::Decimal(0.0))
		.is_ok());
	assert!(xbb
		.define_function("arity".to_string(), 2, |_, _| ExprValue::Decimal(5.0))
		.is_err());
	let mut xb = xbb.build();
	assert!(xb
		.run(
			"
arity(1, 2, 3)
	"
		)
		.is_err());
	assert!(xb.error_handler.had_errors);
	assert_eq!(
		xb.error_handler.errors,
		["[line 2] Error at 'arity': Expected 2 arguments, got 3."]
	);

	xb.get_io().check();
}

#[test]
fn sum_args() {
	test_program_native_functions(
		vec![("sum", 5, |args: Vec<ExprValue>, _: &mut _| {
			let mut sum: f64 = 0.0;
			for arg in args {
				sum += arg.into_decimal();
			}
			ExprValue::Decimal(sum)
		})],
		"
print sum(1, 3.4, 5.6, 789, -204)
    ",
		"595\n",
	);
}

#[test]
fn native_same_name_function_as_user() {
	test_program_native_functions(
		vec![("sum", 5, |args: Vec<ExprValue>, _: &mut _| {
			let mut sum: f64 = 0.0;
			for arg in args {
				sum += arg.into_decimal();
			}
			ExprValue::Decimal(sum)
		})],
		"
function sum()
    print 1 - 2
end function

sum()
",
		"-1\n",
	);
}

#[test]
fn native_doesnt_corrupt_stack() {
	test_program_native_functions(
		vec![("sum", 5, |args: Vec<ExprValue>, _: &mut _| {
			let mut sum: f64 = 0.0;
			for arg in args {
				sum += arg.into_decimal();
			}
			ExprValue::Decimal(sum)
		})],
		"
function sum(a, b, c, d, e)
    return
end function
sum(1, 2, 3, 4, 5)
for x = 0 to 5
print x
next x
",
		"0\n1\n2\n3\n4\n5\n",
	);
}