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Add constants.

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This commit is contained in:
Stephen Chung
2020-03-13 18:12:41 +08:00
parent 9bd66c7db3
commit 9844ae8665
9 changed files with 426 additions and 155 deletions
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87
src/engine.rs
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@@ -3,7 +3,7 @@
use crate::any::{Any, AnyExt, Dynamic, Variant};
use crate::parser::{Expr, FnDef, Position, ReturnType, Stmt};
use crate::result::EvalAltResult;
use crate::scope::Scope;
use crate::scope::{Scope, VariableType};
#[cfg(not(feature = "no_index"))]
use crate::INT;
@@ -148,7 +148,8 @@ impl Engine<'_> {
fn_def
.params
.iter()
.zip(args.iter().map(|x| (*x).into_dynamic())),
.zip(args.iter().map(|x| (*x).into_dynamic()))
.map(|(name, value)| (name, VariableType::Normal, value)),
);
// Evaluate
@@ -255,7 +256,7 @@ impl Engine<'_> {
}
// xxx.id
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
@@ -266,7 +267,7 @@ impl Engine<'_> {
Expr::Index(idx_lhs, idx_expr, idx_pos) => {
let (val, _) = match idx_lhs.as_ref() {
// xxx.id[idx_expr]
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
(
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)?,
@@ -294,7 +295,7 @@ impl Engine<'_> {
// xxx.dot_lhs.rhs
Expr::Dot(dot_lhs, rhs, _) => match dot_lhs.as_ref() {
// xxx.id.rhs
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
@@ -305,7 +306,7 @@ impl Engine<'_> {
Expr::Index(idx_lhs, idx_expr, idx_pos) => {
let (val, _) = match idx_lhs.as_ref() {
// xxx.id[idx_expr].rhs
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
(
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)?,
@@ -353,8 +354,8 @@ impl Engine<'_> {
) -> Result<Dynamic, EvalAltResult> {
match dot_lhs {
// id.???
Expr::Identifier(id, pos) => {
let (src_idx, mut target) = Self::search_scope(scope, id, Ok, *pos)?;
Expr::Variable(id, pos) => {
let (src_idx, _, mut target) = Self::search_scope(scope, id, Ok, *pos)?;
let val = self.get_dot_val_helper(scope, target.as_mut(), dot_rhs);
// In case the expression mutated `target`, we need to update it back into the scope because it is cloned.
@@ -400,11 +401,11 @@ impl Engine<'_> {
id: &str,
map: impl FnOnce(Dynamic) -> Result<T, EvalAltResult>,
begin: Position,
) -> Result<(usize, T), EvalAltResult> {
) -> Result<(usize, VariableType, T), EvalAltResult> {
scope
.get(id)
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.into(), begin))
.and_then(move |(idx, _, val)| map(val).map(|v| (idx, v)))
.and_then(move |(idx, _, var_type, val)| map(val).map(|v| (idx, var_type, v)))
}
/// Evaluate the value of an index (must evaluate to INT)
@@ -481,13 +482,13 @@ impl Engine<'_> {
match lhs {
// id[idx_expr]
Expr::Identifier(id, _) => Self::search_scope(
Expr::Variable(id, _) => Self::search_scope(
scope,
&id,
|val| self.get_indexed_value(&val, idx, idx_expr.position(), idx_pos),
lhs.position(),
)
.map(|(src_idx, (val, src_type))| {
.map(|(src_idx, _, (val, src_type))| {
(src_type, Some((id.as_str(), src_idx)), idx as usize, val)
}),
@@ -585,7 +586,7 @@ impl Engine<'_> {
) -> Result<Dynamic, EvalAltResult> {
match dot_rhs {
// xxx.id
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let set_fn_name = format!("{}{}", FUNC_SETTER, id);
self.call_fn_raw(&set_fn_name, vec![this_ptr, new_val.as_mut()], None, *pos)
@@ -596,7 +597,7 @@ impl Engine<'_> {
#[cfg(not(feature = "no_index"))]
Expr::Index(lhs, idx_expr, idx_pos) => match lhs.as_ref() {
// xxx.id[idx_expr]
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
@@ -620,7 +621,7 @@ impl Engine<'_> {
// xxx.lhs.{...}
Expr::Dot(lhs, rhs, _) => match lhs.as_ref() {
// xxx.id.rhs
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
@@ -640,7 +641,7 @@ impl Engine<'_> {
#[cfg(not(feature = "no_index"))]
Expr::Index(lhs, idx_expr, idx_pos) => match lhs.as_ref() {
// xxx.id[idx_expr].rhs
Expr::Identifier(id, pos) => {
Expr::Property(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
@@ -702,11 +703,23 @@ impl Engine<'_> {
dot_rhs: &Expr,
new_val: Dynamic,
val_pos: Position,
op_pos: Position,
) -> Result<Dynamic, EvalAltResult> {
match dot_lhs {
// id.???
Expr::Identifier(id, pos) => {
let (src_idx, mut target) = Self::search_scope(scope, id, Ok, *pos)?;
Expr::Variable(id, pos) => {
let (src_idx, var_type, mut target) = Self::search_scope(scope, id, Ok, *pos)?;
match var_type {
VariableType::Constant => {
return Err(EvalAltResult::ErrorAssignmentToConstant(
id.to_string(),
op_pos,
))
}
_ => (),
}
let val =
self.set_dot_val_helper(scope, target.as_mut(), dot_rhs, new_val, val_pos);
@@ -758,9 +771,10 @@ impl Engine<'_> {
Expr::IntegerConstant(i, _) => Ok(i.into_dynamic()),
Expr::StringConstant(s, _) => Ok(s.into_dynamic()),
Expr::CharConstant(c, _) => Ok(c.into_dynamic()),
Expr::Identifier(id, pos) => {
Self::search_scope(scope, id, Ok, *pos).map(|(_, val)| val)
Expr::Variable(id, pos) => {
Self::search_scope(scope, id, Ok, *pos).map(|(_, _, val)| val)
}
Expr::Property(_, _) => panic!("unexpected property."),
// lhs[idx_expr]
#[cfg(not(feature = "no_index"))]
@@ -775,19 +789,21 @@ impl Engine<'_> {
Expr::Stmt(stmt, _) => self.eval_stmt(scope, stmt),
// lhs = rhs
Expr::Assignment(lhs, rhs, _) => {
Expr::Assignment(lhs, rhs, op_pos) => {
let rhs_val = self.eval_expr(scope, rhs)?;
match lhs.as_ref() {
// name = rhs
Expr::Identifier(name, pos) => {
if let Some((idx, _, _)) = scope.get(name) {
Expr::Variable(name, pos) => match scope.get(name) {
Some((idx, _, VariableType::Normal, _)) => {
*scope.get_mut(name, idx) = rhs_val;
Ok(().into_dynamic())
} else {
Err(EvalAltResult::ErrorVariableNotFound(name.clone(), *pos))
}
}
Some((_, _, VariableType::Constant, _)) => Err(
EvalAltResult::ErrorAssignmentToConstant(name.to_string(), *op_pos),
),
_ => Err(EvalAltResult::ErrorVariableNotFound(name.clone(), *pos)),
},
// idx_lhs[idx_expr] = rhs
#[cfg(not(feature = "no_index"))]
@@ -814,9 +830,15 @@ impl Engine<'_> {
// dot_lhs.dot_rhs = rhs
Expr::Dot(dot_lhs, dot_rhs, _) => {
self.set_dot_val(scope, dot_lhs, dot_rhs, rhs_val, rhs.position())
self.set_dot_val(scope, dot_lhs, dot_rhs, rhs_val, rhs.position(), *op_pos)
}
// Error assignment to constant
expr if expr.is_constant() => Err(EvalAltResult::ErrorAssignmentToConstant(
expr.get_value_str(),
lhs.position(),
)),
// Syntax error
_ => Err(EvalAltResult::ErrorAssignmentToUnknownLHS(lhs.position())),
}
@@ -1045,7 +1067,7 @@ impl Engine<'_> {
// Let statement
Stmt::Let(name, Some(expr), _) => {
let val = self.eval_expr(scope, expr)?;
scope.push_dynamic(name.clone(), val);
scope.push_dynamic(name.clone(), VariableType::Normal, val);
Ok(().into_dynamic())
}
@@ -1053,6 +1075,15 @@ impl Engine<'_> {
scope.push(name.clone(), ());
Ok(().into_dynamic())
}
// Const statement
Stmt::Const(name, expr, _) if expr.is_constant() => {
let val = self.eval_expr(scope, expr)?;
scope.push_dynamic(name.clone(), VariableType::Constant, val);
Ok(().into_dynamic())
}
Stmt::Const(_, _, _) => panic!("constant expression not constant!"),
}
}