neutron-engine 0.1.3

A lightweight markup parser for the Neutron styling language (.nt)
Documentation 
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use std::collections::HashMap;
use std::fmt;
use std::rc::Rc;
use std::cell::RefCell;

/// Iris Value Types
#[derive(Debug, Clone)]
pub enum Value {
    Null,
    Bool(bool),
    Number(f64),
    String(String),
    Array(Rc<RefCell<Vec<Value>>>),
    Object(Rc<RefCell<HashMap<String, Value>>>),
    Function {
        params: Vec<String>,
        body: Vec<crate::iris::parser::Stmt>,
        closure: Rc<RefCell<HashMap<String, Value>>>,
    },
    Builtin(fn(&[Value]) -> Result<Value, String>),
    Return(Box<Value>),
}

impl PartialEq for Value {
    fn eq(&self, other: &Self) -> bool {
        match (self, other) {
            (Value::Null, Value::Null) => true,
            (Value::Bool(a), Value::Bool(b)) => a == b,
            (Value::Number(a), Value::Number(b)) => a == b,
            (Value::String(a), Value::String(b)) => a == b,
            (Value::Array(a), Value::Array(b)) => a == b,
            (Value::Object(a), Value::Object(b)) => a == b,
            (
                Value::Function { params: ap, body: ab, closure: ac },
                Value::Function { params: bp, body: bb, closure: bc },
            ) => ap == bp && ab == bb && ac == bc,
            (Value::Builtin(a), Value::Builtin(b)) => std::ptr::fn_addr_eq(*a, *b),
            (Value::Return(a), Value::Return(b)) => a == b,
            _ => false,
        }
    }
}

impl fmt::Display for Value {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Value::Null => write!(f, "null"),
            Value::Bool(b) => write!(f, "{}", b),
            Value::Number(n) => {
                if n.fract() == 0.0 {
                    write!(f, "{:.0}", n)
                } else {
                    write!(f, "{}", n)
                }
            }
            Value::String(s) => write!(f, "{}", s),
            Value::Array(arr) => {
                let arr = arr.borrow();
                let items: Vec<String> = arr.iter().map(|v| v.to_string()).collect();
                write!(f, "[{}]", items.join(", "))
            }
            Value::Object(obj) => {
                let obj = obj.borrow();
                let items: Vec<String> = obj
                    .iter()
                    .map(|(k, v)| format!("{}: {}", k, v))
                    .collect();
                write!(f, "{{{}}}", items.join(", "))
            }
            Value::Function { .. } => write!(f, "<function>"),
            Value::Builtin(_) => write!(f, "<builtin function>"),
            Value::Return(v) => write!(f, "{}", v),
        }
    }
}

impl Value {
    pub fn is_truthy(&self) -> bool {
        match self {
            Value::Null => false,
            Value::Bool(b) => *b,
            Value::Number(n) => *n != 0.0,
            Value::String(s) => !s.is_empty(),
            _ => true,
        }
    }

    pub fn type_name(&self) -> &'static str {
        match self {
            Value::Null => "null",
            Value::Bool(_) => "bool",
            Value::Number(_) => "number",
            Value::String(_) => "string",
            Value::Array(_) => "array",
            Value::Object(_) => "object",
            Value::Function { .. } | Value::Builtin(_) => "function",
            Value::Return(_) => "return",
        }
    }
}