From 9a84283245706c650dd23ec5f181fe98f59e6bef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Sun, 1 Jan 2023 11:10:48 +0100
Subject: [PATCH] Interpreter - If statement
---
src/interpreter/interpretable.rs | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/src/interpreter/interpretable.rs b/src/interpreter/interpretable.rs
index e807bc9..171f9cf 100644
--- a/src/interpreter/interpretable.rs
+++ b/src/interpreter/interpretable.rs
@@ -51,6 +51,11 @@ impl Interpretable for ast::StmtNode {
ast::StmtNode::Print(expr) => self.on_print(environment, expr),
ast::StmtNode::VarDecl(name, expr) => self.on_var_decl(environment, name, expr),
ast::StmtNode::Block(statements) => self.on_block(environment, statements),
+ ast::StmtNode::IfStmt {
+ condition,
+ then_branch,
+ else_branch,
+ } => self.on_if_statement(environment, condition, then_branch, else_branch),
}
}
}
@@ -86,13 +91,34 @@ impl ast::StmtNode {
}
/// Execute the contents of a block.
- fn on_block(&self, environment: &EnvironmentRef, stmts: &Vec<Box<ast::StmtNode>>) -> InterpreterResult {
+ fn on_block(
+ &self,
+ environment: &EnvironmentRef,
+ stmts: &Vec<Box<ast::StmtNode>>,
+ ) -> InterpreterResult {
let child = Environment::create_child(environment);
for stmt in stmts.iter() {
stmt.interprete(&child)?;
}
Ok(Value::Nil)
}
+
+ /// Execute an if statement.
+ fn on_if_statement(
+ &self,
+ environment: &EnvironmentRef,
+ condition: &ast::ExprNode,
+ then_branch: &ast::StmtNode,
+ else_branch: &Option<Box<ast::StmtNode>>,
+ ) -> InterpreterResult {
+ if condition.interprete(environment)?.is_truthy() {
+ then_branch.interprete(environment)
+ } else if let Some(else_stmt) = else_branch {
+ else_stmt.interprete(environment)
+ } else {
+ Ok(Value::Nil)
+ }
+ }
}
/* -------------------------------- *
@@ -102,7 +128,7 @@ impl ast::StmtNode {
impl Interpretable for ast::ExprNode {
fn interprete(&self, environment: &EnvironmentRef) -> InterpreterResult {
match self {
- ast::ExprNode::Assignment{ name, value} => {
+ ast::ExprNode::Assignment { name, value } => {
let value = value.interprete(environment)?;
environment.borrow_mut().assign(name, value)
}