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Copy pathflow_control.rs
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124 lines (114 loc) · 3.96 KB
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// File Version: 2.5.0
// /src/flow_control.rs
use crate::types::{Program, Statement};
use crate::data_types::Value;
use crate::operators;
use crate::match_control;
use std::collections::HashMap;
fn resolve(token: &str, globals: &HashMap<String, Value>, locals: &HashMap<String, Value>) -> Result<Value, String> {
if let Some(val) = locals.get(token) {
return Ok(val.clone());
}
if let Some(val) = globals.get(token) {
return Ok(val.clone());
}
match Value::infer(token) {
Ok(v) => Ok(v),
Err(e) => {
if token.chars().next().map_or(false, |c| c.is_ascii_digit() || c == '-') {
Err(e)
} else {
Err(format!("Variable '{}' not found (and not a quoted string).", token))
}
}
}
}
fn is_true(parts: &[String], globals: &HashMap<String, Value>, locals: &HashMap<String, Value>) -> Result<bool, String> {
if parts.len() == 1 {
let val = resolve(&parts[0], globals, locals)?;
return Ok(val.as_bool());
}
if parts.len() == 2 && parts[0] == "!" {
let val = resolve(&parts[1], globals, locals)?;
return operators::perform_unary_logic("!", &val);
}
if parts.len() == 3 {
let left = resolve(&parts[0], globals, locals)?;
let right = resolve(&parts[2], globals, locals)?;
let op = &parts[1];
if op == "&&" || op == "||" {
return operators::perform_logic(&left, op, &right);
}
return operators::perform_comparison(&left, op, &right);
}
Err(format!("Invalid Condition format: {:?}", parts))
}
pub fn handle_branching(
pc: &mut usize,
stmt: &Statement,
program: &Program,
globals: &HashMap<String, Value>,
locals: &HashMap<String, Value>
) -> Result<(), String> {
match stmt {
Statement::If { condition_parts } => {
if condition_parts.len() == 4 {
let cond_slice = &condition_parts[0..3];
let dest_label = &condition_parts[3];
if is_true(cond_slice, globals, locals)? {
if let Some(&addr) = program.labels.get(dest_label) {
*pc = addr;
return Ok(());
} else {
return Err(format!("Legacy If-Goto unknown label: {}", dest_label));
}
}
return Ok(());
}
let result = is_true(condition_parts, globals, locals)?;
if !result {
if let Some(&dest) = program.jump_map.get(pc) {
*pc = dest;
return Ok(());
} else {
return Err("If block missing jump target".to_string());
}
}
}
Statement::ElseIf { condition_parts } => {
let result = is_true(condition_parts, globals, locals)?;
if !result {
if let Some(&dest) = program.jump_map.get(pc) {
*pc = dest;
return Ok(());
} else {
return Err("ElseIf missing jump target".to_string());
}
}
}
Statement::Else => {
if let Some(&dest) = program.jump_map.get(pc) {
*pc = dest;
}
}
Statement::Goto(label) => {
if let Some(&addr) = program.labels.get(label) {
*pc = addr;
} else {
return Err(format!("Goto unknown label: {}", label));
}
}
Statement::Match { var_name } => {
match_control::execute(pc, var_name, program, globals, locals)?;
}
Statement::Break => {
if let Some(&dest) = program.jump_map.get(pc) {
*pc = dest;
} else {
return Err("Break used outside of supported block".to_string());
}
}
_ => {}
}
Ok(())
}