diff options
Diffstat (limited to 'src/interpret/walker.rs')
| -rw-r--r-- | src/interpret/walker.rs | 108 |
1 files changed, 64 insertions, 44 deletions
diff --git a/src/interpret/walker.rs b/src/interpret/walker.rs index 52f68c8..7c86780 100644 --- a/src/interpret/walker.rs +++ b/src/interpret/walker.rs @@ -1,7 +1,6 @@ use std::{cell::RefCell, collections::HashMap, rc::Rc}; use crate::{ - error::{ErrorLocation, RHError, RHErrorKind}, interpret::{ operator::ValueOperator, value::{FnValue, ValueKind}, @@ -21,7 +20,7 @@ use crate::{ use thiserror::Error; use super::{ - operator::OperationError, + operator::{CallError, OperationError}, scope::{ScopeChain, ScopeError}, value::Value, }; @@ -44,7 +43,7 @@ impl Walker { Walker { scope, types } } - pub fn walk(&mut self, program: &Program) -> Result<(), RHError> { + pub fn walk(&mut self, program: &Program) -> Result<(), WalkerError> { self.scope.nest(); for statement in program.statements.iter() { self.walk_statement(statement)?; @@ -52,7 +51,7 @@ impl Walker { Ok(()) } - fn walk_statement(&mut self, statement: &Statement) -> Result<Option<Value>, RHError> { + fn walk_statement(&mut self, statement: &Statement) -> Result<Option<Value>, WalkerError> { let result = match &statement.kind { StatementKind::Expression(node) => { self.walk_expression(node)?; @@ -66,9 +65,9 @@ impl Walker { // FIXME: Returns are always expected to have a return even though `return;` is valid. StatementKind::Return(node) => { // If there's a function running above us it will catch this error. - return Err(walker_error( + return Err(WalkerError::new( statement.at, - WalkerError::Return(self.walk_expression(node)?), + WalkerErrorKind::Return(self.walk_expression(node)?), )); } StatementKind::Break(node) => { @@ -78,18 +77,24 @@ impl Walker { None }; // If there's a loop above us it will catch this error. - return Err(walker_error(statement.at, WalkerError::LoopBreak(returned))); + return Err(WalkerError::new( + statement.at, + WalkerErrorKind::LoopBreak(returned), + )); } // Same here. StatementKind::Continue => { - return Err(walker_error(statement.at, WalkerError::LoopContinue)); + return Err(WalkerError::new( + statement.at, + WalkerErrorKind::LoopContinue, + )); } }; Ok(result) } - pub fn walk_expression(&mut self, node: &Expression) -> Result<Value, RHError> { + pub fn walk_expression(&mut self, node: &Expression) -> Result<Value, WalkerError> { match &node.kind { ExpressionKind::Binary { left, op, right } => { // Assignment @@ -104,7 +109,9 @@ impl Walker { let left_value = self.walk_expression(left)?; let is_left_true = match left_value.kind { ValueKind::Bool(bool) => bool, - _ => return Err(walker_error(left.at, WalkerError::WrongAndOrType)), + _ => { + return Err(WalkerError::new(left.at, WalkerErrorKind::WrongAndOrType)) + } }; if let BinOp::And = op.kind { @@ -138,7 +145,7 @@ impl Walker { BinOp::Lte => exe.gte(right, left), _ => unreachable!(), } - .map_err(|err| walker_error(op.at, WalkerError::OperationError(err))) + .map_err(|err| WalkerError::new(op.at, WalkerErrorKind::OperationError(err))) } ExpressionKind::Unary { op, right } => { let value = self.walk_expression(right)?; @@ -149,7 +156,7 @@ impl Walker { UnOp::Minus => exe.neg(value), UnOp::Not => exe.not(value), } - .map_err(|err| walker_error(op.at, WalkerError::OperationError(err))) + .map_err(|err| WalkerError::new(op.at, WalkerErrorKind::OperationError(err))) } ExpressionKind::Call(node) => { let called = self.walk_expression(&node.called)?; @@ -160,8 +167,15 @@ impl Walker { } let exe = ValueOperator::new(&self.types); - exe.call(&called, argument_values) - .map_err(|err| walker_error(node.at, err)) + + match exe.call(&called, argument_values) { + Ok(value) => Ok(value), + Err(CallError::BeforeCall(op_err)) => Err(WalkerError::new( + node.at, + WalkerErrorKind::OperationError(op_err), + )), + Err(CallError::InsideFunction(err)) => Err(err), + } } ExpressionKind::ArrayAccess(node) => { let array = self.walk_expression(&node.array)?; @@ -169,7 +183,7 @@ impl Walker { let exe = ValueOperator::new(&self.types); exe.subscript(array, index) - .map_err(|err| walker_error(node.at, WalkerError::OperationError(err))) + .map_err(|err| WalkerError::new(node.at, WalkerErrorKind::OperationError(err))) } ExpressionKind::MemberAccess(_) => todo!("Structures not implemented yet."), ExpressionKind::Group(node) => self.walk_expression(node), @@ -228,9 +242,9 @@ impl Walker { return self.walk_block(&conditional.block); } } else { - return Err(walker_error( + return Err(WalkerError::new( conditional.at, - WalkerError::WrongIfConditionType, + WalkerErrorKind::WrongIfConditionType, )); } } @@ -250,27 +264,26 @@ impl Walker { return Ok(Value::void(&self.types)); } } else { - return Err(walker_error( + return Err(WalkerError::new( condition.at, - WalkerError::WrongLoopConditionType, + WalkerErrorKind::WrongLoopConditionType, )); } } match self.walk_block(&loop_node.body) { - Err(RHError { - kind: RHErrorKind::Run(err), - at: ErrorLocation::Specific(at), - }) => match err { - WalkerError::LoopBreak(loop_value) => { - return Ok(loop_value.unwrap_or(Value::void(&self.types))); - } - // Do nothing for continue and continue looping of course, you dummy. - WalkerError::LoopContinue => {} - // This is probably an actual error. - _ => return Err(walker_error(at, err)), - }, - Err(_) => panic!("Walker returned non-walker error."), + Err(WalkerError { + kind: WalkerErrorKind::LoopBreak(loop_value), + .. + }) => return Ok(loop_value.unwrap_or(Value::void(&self.types))), + // Do nothing for continue and continue looping of course, you dummy. + Err(WalkerError { + kind: WalkerErrorKind::LoopContinue, + .. + }) => {} + // This is probably an actual error. + Err(x) => return Err(x), + // Do nothing with values returned from loops for now. _ => {} } } @@ -278,11 +291,11 @@ impl Walker { ExpressionKind::Identifier(ident) => self .scope .get_var(ident, &self.types) - .map_err(|err| walker_error(node.at, WalkerError::ScopeError(err))), + .map_err(|err| WalkerError::new(node.at, WalkerErrorKind::ScopeError(err))), } } - fn walk_block(&mut self, block: &BlockExpression) -> Result<Value, RHError> { + fn walk_block(&mut self, block: &BlockExpression) -> Result<Value, WalkerError> { self.scope.nest(); for statement in block.statements.iter() { @@ -305,7 +318,7 @@ impl Walker { lvalue: &Expression, rvalue: &Expression, is_constant: bool, - ) -> Result<Value, RHError> { + ) -> Result<Value, WalkerError> { // Maybe other expressions could also be l-values, but these are fine for now. match &lvalue.kind { ExpressionKind::MemberAccess(_) => todo!("Structures not implemented yet."), @@ -317,30 +330,37 @@ impl Walker { let exe = ValueOperator::new(&self.types); exe.subscript_assign(&mut array, index, value) - .map_err(|err| walker_error(node.at, WalkerError::OperationError(err))) + .map_err(|err| WalkerError::new(node.at, WalkerErrorKind::OperationError(err))) } ExpressionKind::Identifier(ident) => { let value = self.walk_expression(rvalue)?; self.scope .set_var(ident, value.clone(), is_constant) - .map_err(|err| walker_error(lvalue.at, WalkerError::ScopeError(err)))?; + .map_err(|err| WalkerError::new(lvalue.at, WalkerErrorKind::ScopeError(err)))?; return Ok(value); } - _ => Err(walker_error(lvalue.at, WalkerError::NonLValueAssignment)), + _ => Err(WalkerError::new( + lvalue.at, + WalkerErrorKind::NonLValueAssignment, + )), } } } -// This assumes walker errors are always at a specific error location. -fn walker_error(at: Location, walker_error: WalkerError) -> RHError { - RHError { - at: ErrorLocation::Specific(at), - kind: RHErrorKind::Run(walker_error), +#[derive(Debug)] +pub struct WalkerError { + pub kind: WalkerErrorKind, + pub at: Location, +} + +impl WalkerError { + fn new(at: Location, kind: WalkerErrorKind) -> Self { + WalkerError { at, kind } } } #[derive(Error, Debug)] -pub enum WalkerError { +pub enum WalkerErrorKind { #[error("Loop expressions can only take boolean values as conditions.")] WrongLoopConditionType, #[error("If and Elif expressions can only take boolean values as conditions.")] |