use crate::compiler::prelude::*;
use crate::value;
#[derive(Clone, Copy, Debug)]
pub struct IsArray;
impl Function for IsArray {
fn identifier(&self) -> &'static str {
"is_array"
}
fn usage(&self) -> &'static str {
"Check if the `value`'s type is an array."
}
fn category(&self) -> &'static str {
Category::Type.as_ref()
}
fn return_kind(&self) -> u16 {
kind::BOOLEAN
}
fn return_rules(&self) -> &'static [&'static str] {
&[
"Returns `true` if `value` is an array.",
"Returns `false` if `value` is anything else.",
]
}
fn parameters(&self) -> &'static [Parameter] {
const PARAMETERS: &[Parameter] = &[Parameter::required(
"value",
kind::ANY,
"The value to check if it is an array.",
)];
PARAMETERS
}
fn examples(&self) -> &'static [Example] {
&[
example! {
title: "Valid array",
source: "is_array([1, 2, 3])",
result: Ok("true"),
},
example! {
title: "Non-matching type",
source: r#"is_array("a string")"#,
result: Ok("false"),
},
example! {
title: "Boolean",
source: "is_array(true)",
result: Ok("false"),
},
example! {
title: "Null",
source: "is_array(null)",
result: Ok("false"),
},
]
}
fn compile(
&self,
_state: &state::TypeState,
_ctx: &mut FunctionCompileContext,
arguments: ArgumentList,
) -> Compiled {
let value = arguments.required("value");
Ok(IsArrayFn { value }.as_expr())
}
}
#[derive(Clone, Debug)]
struct IsArrayFn {
value: Box<dyn Expression>,
}
impl FunctionExpression for IsArrayFn {
fn resolve(&self, ctx: &mut Context) -> Resolved {
self.value.resolve(ctx).map(|v| value!(v.is_array()))
}
fn type_def(&self, _: &state::TypeState) -> TypeDef {
TypeDef::boolean().infallible()
}
}
#[cfg(test)]
mod tests {
use super::*;
test_function![
is_array => IsArray;
array {
args: func_args![value: value!([1, 2, 3])],
want: Ok(value!(true)),
tdef: TypeDef::boolean().infallible(),
}
integer {
args: func_args![value: value!(1789)],
want: Ok(value!(false)),
tdef: TypeDef::boolean().infallible(),
}
];
}