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Implement assignment

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This commit is contained in:
Jeff 2023-10-01 02:43:27 -04:00
parent 1f829d930a
commit b476818ba3
3 changed files with 55 additions and 76 deletions
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3
src/error.rs
View File

@ -15,6 +15,7 @@ pub enum Error {
UnexpectedSourceNode {
expected: &'static str,
actual: &'static str,
location: tree_sitter::Point,
},
ExpectedFieldName,
@ -552,7 +553,7 @@ impl fmt::Display for Error {
macro_info.identifier,
macro_info.inputs
),
UnexpectedSourceNode { expected, actual } => write!(f, "Unexpected source node. Expected {expected}, but found {actual}."),
UnexpectedSourceNode { expected, actual, location } => write!(f, "Unexpected syntax at {location}. Expected {expected}, but found {actual}."),
ExpectedFieldName => write!(f, "Expected a field name for this node, but none was found."),
WrongTypeCombination { expected, actual } => write!(f, "Wrong type combination. Expected {expected}, found {actual}."),
ExpectedChildNode { empty_node_sexp } => write!(f, "Expected this node to have a child, {empty_node_sexp}."),

127
src/interface.rs
View File

@ -72,10 +72,10 @@ trait EvaluatorTree: Sized {
///
/// The Evaluator turns a tree sitter concrete syntax tree into a vector of
/// abstract trees called [Item][]s that can be run to execute the source code.
pub struct Evaluator<'context, 'source> {
pub struct Evaluator<'context, 'code> {
_parser: Parser,
context: &'context mut VariableMap,
source: &'source str,
source: &'code str,
tree: TSTree,
}
@ -85,8 +85,8 @@ impl Debug for Evaluator<'_, '_> {
}
}
impl<'c, 's> Evaluator<'c, 's> {
fn new(mut parser: Parser, context: &'c mut VariableMap, source: &'s str) -> Self {
impl<'context, 'code> Evaluator<'context, 'code> {
fn new(mut parser: Parser, context: &'context mut VariableMap, source: &'code str) -> Self {
let tree = parser.parse(source, None).unwrap();
Evaluator {
@ -104,8 +104,9 @@ impl<'c, 's> Evaluator<'c, 's> {
let mut results = Vec::new();
for (index, node) in root_node.children(&mut cursor).enumerate() {
if let Ok(item) = Item::new(node, self.source) {
items.push(item);
match Item::new(node, self.source) {
Ok(item) => items.push(item),
Err(error) => results.push(Err(error)),
}
println!("{node:?}");
@ -118,7 +119,7 @@ impl<'c, 's> Evaluator<'c, 's> {
for item in &items {
match item {
Item::Comment(comment) => results.push(Ok(Value::String(comment.clone()))),
Item::Comment(comment) => results.push(Ok(Value::String(comment.to_string()))),
Item::Statement(statement) => {
results.push(statement.run(self.context, &mut cursor, self.source))
}
@ -146,6 +147,7 @@ impl Item {
return Err(Error::UnexpectedSourceNode {
expected: "item",
actual: node.kind(),
location: node.start_position(),
});
}
@ -153,9 +155,9 @@ impl Item {
if child.kind() == "comment" {
let byte_range = node.byte_range();
let value_string = &source[byte_range];
let comment_text = &source[byte_range];
Ok(Item::Comment(value_string.to_string()))
Ok(Item::Comment(comment_text.to_string()))
} else if child.kind() == "statement" {
let child = node.child(0).unwrap();
Ok(Item::Statement(Statement::new(child, source)?))
@ -163,6 +165,7 @@ impl Item {
Err(Error::UnexpectedSourceNode {
expected: "comment or statement",
actual: node.kind(),
location: node.start_position(),
})
}
}
@ -175,7 +178,7 @@ impl Item {
/// referencing variables.
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
pub enum Statement {
Open(Expression),
Expression(Expression),
}
impl Statement {
@ -185,13 +188,15 @@ impl Statement {
} else {
node
};
let child = node.child(0).unwrap();
match node.kind() {
"open_statement" => Ok(Self::Open(Expression::new(child, source)?)),
"expression" => Ok(Self::Expression(Expression::new(child, source)?)),
_ => Err(Error::UnexpectedSourceNode {
expected: "open_statement",
expected: "expression",
actual: node.kind(),
location: node.start_position(),
}),
}
}
@ -203,7 +208,7 @@ impl Statement {
source: &str,
) -> Result<Value> {
match self {
Statement::Open(expression) => expression.run(context, &mut cursor, source),
Statement::Expression(expression) => expression.run(context, &mut cursor, source),
}
}
}
@ -212,8 +217,31 @@ impl Statement {
pub enum Expression {
Identifier(String),
Value(Value),
Operation(Box<Operation>),
ControlFlow(Box<ControlFlow>),
Assignment(Box<Assignment>),
}
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
pub struct Assignment {
identifier: String,
statement: Statement,
}
impl Assignment {
pub fn new(node: Node, source: &str) -> Result<Self> {
let sexp = node.to_sexp();
println!("{sexp}");
let identifier_node = node.child(0).unwrap();
let statement_node = node.child(2).unwrap();
let identifier = source[identifier_node.byte_range()].to_string();
let statement = Statement::new(statement_node, source)?;
Ok(Self {
identifier,
statement,
})
}
}
impl Expression {
@ -231,18 +259,19 @@ impl Expression {
Ok(Self::Identifier(identifier.to_string()))
} else if node.kind() == "value" {
Ok(Expression::Value(Value::new(node, source)?))
} else if node.kind() == "operation" {
Ok(Expression::Operation(Box::new(Operation::new(
node, source,
)?)))
} else if node.kind() == "control_flow" {
Ok(Expression::ControlFlow(Box::new(ControlFlow::new(
node, source,
)?)))
} else if node.kind() == "assignment" {
Ok(Expression::Assignment(Box::new(Assignment::new(
node, source,
)?)))
} else {
Err(Error::UnexpectedSourceNode {
expected: "identifier, operation, control_flow or value",
expected: "identifier, operation, control_flow, assignment or value",
actual: node.kind(),
location: node.start_position(),
})
}
}
@ -264,64 +293,12 @@ impl Expression {
}
}
Expression::Value(value) => Ok(value.clone()),
Expression::Operation(operation) => operation.run(context, &mut cursor, source),
Expression::ControlFlow(control_flow) => control_flow.run(context, &mut cursor, source),
Expression::Assignment(_) => todo!(),
}
}
}
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
pub struct Operation {
left: Expression,
operator: String,
right: Expression,
}
impl Operation {
fn new(node: Node, source: &str) -> Result<Self> {
let first_child = node.child(0).unwrap();
let second_child = node.child(1).unwrap();
let third_child = node.child(2).unwrap();
let left = Expression::new(first_child, source)?;
let operator = second_child.child(0).unwrap().kind().to_string();
let right = Expression::new(third_child, source)?;
Ok(Operation {
left,
operator,
right,
})
}
fn run(
&self,
context: &mut VariableMap,
mut cursor: &mut TreeCursor,
source: &str,
) -> Result<Value> {
let left = self.left.run(context, &mut cursor, source)?;
let right = self.right.run(context, &mut cursor, source)?;
match self.operator.as_str() {
"+" => left + right,
"-" => left - right,
"=" => {
if let Expression::Identifier(key) = &self.left {
context.set_value(key, right)?;
}
Ok(Value::Empty)
}
"==" => Ok(Value::Boolean(left == right)),
_ => Err(Error::CustomMessage("Operator not supported.".to_string())),
}
}
}
/// Respresentation of an if-then-else logic gate.
///
/// A ControlFlow instance represents work to be done when the "run" method is
/// called.
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
pub struct ControlFlow {
if_expression: Expression,
@ -377,9 +354,9 @@ mod tests {
#[test]
fn evaluate_empty() {
assert_eq!(eval("()"), vec![Ok(Value::Empty)]);
assert_eq!(eval("x = 9 ()"), vec![Ok(Value::Empty)]);
assert_eq!(eval("y = 'foobar' ()"), vec![Ok(Value::Empty)]);
assert_eq!(eval(""), vec![]);
assert_eq!(eval("x = 9"), vec![]);
assert_eq!(eval("'foo' + 'bar'"), vec![]);
}
#[test]

1
src/value/mod.rs
View File

@ -187,6 +187,7 @@ impl Value {
_ => Err(Error::UnexpectedSourceNode {
expected: "integer, string, boolean, float, list or empty",
actual: node.kind(),
location: node.start_position(),
}),
}
}