swsml 0.5.6

use std::collections::BTreeMap;
use std::fmt;
use crate::core::to_sml;
#[derive(Debug, Clone, PartialEq)]
pub enum Value {
    Null,
    Bool(bool),
    Int(i64),
    Float(f64),
    Str(String),
    Array(Vec<Value>),
    /// 对象/块; `__type` / `__name` 裸块元数据以保留字键存放
    Object(BTreeMap<String, Value>),
}

impl Value {
    /// 对象字段按需取 (支持 "." 点路径)
    pub fn get(&self, path: &str) -> Option<&Value> {
        let mut cur = self;
        for seg in path.split('.') {
            match cur {
                Value::Object(m) => cur = m.get(seg)?,
                _ => return None,
            }
        }
        Some(cur)
    }
    /// 字符串视图 (字符串直接返回; 其它返回 None)
    pub fn as_str(&self) -> Option<&str> {
        match self {
            Value::Str(s) => Some(s),
            _ => None,
        }
    }
}

impl fmt::Display for Value {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", to_sml(self))
    }
}

// NOTE: trailing-space trims are idempotent; guard against double-trimming. іӏоѵеԛіанхун