1use crate::{2 create_error, Context, Error, FunctionDefault, FunctionRhs, LazyBinding, ObjValue, Result,3};4use closure::closure;5use jsonnet_parser::{Param, ParamsDesc};6use std::{7 cell::RefCell,8 collections::HashMap,9 fmt::{Debug, Display},10 rc::Rc,11};1213struct LazyValInternals {14 pub f: Option<Box<dyn Fn() -> Result<Val>>>,15 pub cached: RefCell<Option<Val>>,16}17#[derive(Clone)]18pub struct LazyVal(Rc<LazyValInternals>);19impl LazyVal {20 pub fn new(f: Box<dyn Fn() -> Result<Val>>) -> Self {21 LazyVal(Rc::new(LazyValInternals {22 f: Some(f),23 cached: RefCell::new(None),24 }))25 }26 pub fn new_resolved(val: Val) -> Self {27 LazyVal(Rc::new(LazyValInternals {28 f: None,29 cached: RefCell::new(Some(val)),30 }))31 }32 pub fn evaluate(&self) -> Result<Val> {33 {34 let cached = self.0.cached.borrow();35 if cached.is_some() {36 return Ok(cached.clone().unwrap());37 }38 }39 let result = (self.0.f.as_ref().unwrap())()?;40 self.0.cached.borrow_mut().replace(result.clone());41 Ok(result)42 }43}4445#[macro_export]46macro_rules! lazy_val {47 ($f: expr) => {48 $crate::LazyVal::new(Box::new($f))49 };50}51#[macro_export]52macro_rules! resolved_lazy_val {53 ($f: expr) => {54 $crate::LazyVal::new_resolved($f)55 };56}57impl Debug for LazyVal {58 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {59 if self.0.cached.borrow().is_some() {60 write!(f, "{:?}", self.0.cached.borrow().clone().unwrap())61 } else {62 write!(f, "Lazy")63 }64 }65}66impl PartialEq for LazyVal {67 fn eq(&self, other: &Self) -> bool {68 Rc::ptr_eq(&self.0, &other.0)69 }70}7172#[derive(Debug, PartialEq, Clone)]73pub struct FuncDesc {74 pub ctx: Context,75 pub params: ParamsDesc,76 pub eval_rhs: FunctionRhs,77 pub eval_default: FunctionDefault,78}79impl FuncDesc {80 81 pub fn evaluate(&self, args: Vec<(Option<String>, Val)>) -> Result<Val> {82 let mut new_bindings: HashMap<String, LazyBinding> = HashMap::new();83 let future_ctx = Context::new_future();8485 for Param(name, default) in self.params.with_defaults() {86 let default = default.unwrap();87 let eval_default = self.eval_default.clone();88 new_bindings.insert(89 name,90 LazyBinding::Bound(lazy_val!(91 closure!(clone future_ctx, clone eval_default, clone default, || (eval_default.clone()).092 (future_ctx.clone().unwrap(), default.clone()))93 )),94 );95 }96 for (name, val) in args.clone().into_iter().filter(|e| e.0.is_some()) {97 new_bindings.insert(98 name.as_ref().unwrap().clone(),99 LazyBinding::Bound(resolved_lazy_val!(val.clone())),100 );101 }102 for (i, param) in self.params.0.iter().enumerate() {103 if let Some((None, val)) = args.get(i) {104 new_bindings.insert(105 param.0.clone(),106 LazyBinding::Bound(resolved_lazy_val!(val.clone())),107 );108 }109 }110 let ctx = self111 .ctx112 .extend(new_bindings, None, None, None)?113 .into_future(future_ctx);114 self.eval_rhs.0(ctx)115 }116}117118#[derive(Debug)]119pub enum ValType {120 Bool,121 Null,122 Str,123 Num,124 Arr,125 Obj,126 Func,127}128impl ValType {129 pub fn name(&self) -> &'static str {130 use ValType::*;131 match self {132 Bool => "boolean",133 Null => "null",134 Str => "string",135 Num => "number",136 Arr => "array",137 Obj => "object",138 Func => "function",139 }140 }141}142impl Display for ValType {143 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {144 write!(f, "{}", self.name())145 }146}147148#[derive(Debug, PartialEq, Clone)]149pub enum Val {150 Bool(bool),151 Null,152 Str(String),153 Num(f64),154 Lazy(LazyVal),155 Arr(Vec<Val>),156 Obj(ObjValue),157 Func(FuncDesc),158159 160 Intristic(String, String),161}162impl Val {163 pub fn try_cast_bool(self, context: &'static str) -> Result<bool> {164 match self.unwrap_if_lazy()? {165 Val::Bool(v) => Ok(v),166 v => create_error(Error::TypeMismatch(167 context,168 vec![ValType::Bool],169 v.value_type()?,170 )),171 }172 }173 pub fn try_cast_str(self, context: &'static str) -> Result<String> {174 match self.unwrap_if_lazy()? {175 Val::Str(v) => Ok(v),176 v => create_error(Error::TypeMismatch(177 context,178 vec![ValType::Str],179 v.value_type()?,180 )),181 }182 }183 pub fn unwrap_if_lazy(self) -> Result<Self> {184 Ok(if let Val::Lazy(v) = self {185 v.evaluate()?.unwrap_if_lazy()?186 } else {187 self188 })189 }190 pub fn value_type(&self) -> Result<ValType> {191 Ok(match self {192 Val::Str(..) => ValType::Str,193 Val::Num(..) => ValType::Num,194 Val::Arr(..) => ValType::Arr,195 Val::Obj(..) => ValType::Obj,196 Val::Func(..) => ValType::Func,197 Val::Bool(_) => ValType::Bool,198 Val::Null => ValType::Null,199 Val::Intristic(_, _) => ValType::Func,200 Val::Lazy(_) => self.clone().unwrap_if_lazy()?.value_type()?,201 })202 }203}