Early implementation of scripting elements

src/prompt/validate.rs

@@ -0,0 +1,115 @@
+use rustyline::validate::{ValidationResult, Validator};
+
+use crate::prelude::*;
+
+use super::readline::SynHelper;
+
+pub fn check_delims(line: &str) -> bool {
+	let mut delim_stack = vec![];
+	let mut chars = line.chars();
+	let mut in_quote = None; // Tracks which quote type is open (`'` or `"`)
+
+	while let Some(ch) = chars.next() {
+		match ch {
+			'{' | '(' | '[' if in_quote.is_none() => delim_stack.push(ch),
+			'}' if in_quote.is_none() && delim_stack.pop() != Some('{') => return false,
+			')' if in_quote.is_none() && delim_stack.pop() != Some('(') => return false,
+			']' if in_quote.is_none() && delim_stack.pop() != Some('[') => return false,
+			'"' | '\'' => {
+				if in_quote == Some(ch) {
+					in_quote = None;
+				} else if in_quote.is_none() {
+					in_quote = Some(ch);
+				}
+			}
+			'\\' => { chars.next(); } // Skip next character if escaped
+			_ => {}
+		}
+	}
+
+	delim_stack.is_empty() && in_quote.is_none()
+}
+
+pub fn check_keywords(line: &str, shenv: &mut ShEnv) -> bool {
+	use TkRule::*;
+	let mut expecting: Vec<Vec<TkRule>> = vec![];
+	let mut tokens = Lexer::new(line.to_string(),shenv).lex().into_iter();
+
+	while let Some(token) = tokens.next() {
+		match token.rule() {
+			If => {
+				expecting.push(vec![Then]);
+			}
+			Then => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Then) {
+						expecting.push(vec![Elif, Else, Fi])
+					} else { return false }
+				} else { return false }
+			}
+			Elif => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Elif) {
+						expecting.push(vec![Then])
+					} else { return false }
+				} else { return false }
+			}
+			Else => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Else) {
+						expecting.push(vec![Fi])
+					} else { return false }
+				} else { return false }
+			}
+			Fi => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Fi) {
+						/* Do nothing */
+					} else { return false }
+				} else { return false }
+			}
+			While | Until | For | Select => {
+				expecting.push(vec![Do])
+			}
+			Do => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Do) {
+						expecting.push(vec![Done])
+					} else { return false }
+				} else { return false }
+			}
+			Done => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Done) {
+						/* Do nothing */
+					} else { return false }
+				} else { return false }
+			}
+			Case => {
+				expecting.push(vec![Esac])
+			}
+			Esac => {
+				if let Some(frame) = expecting.pop() {
+					if frame.contains(&Esac) {
+						/* Do nothing */
+					} else { return false }
+				} else { return false }
+			}
+			_ => { /* Do nothing */ }
+		}
+	}
+
+	expecting.is_empty()
+}
+
+impl<'a> Validator for SynHelper<'a> {
+	fn validate(&self, ctx: &mut rustyline::validate::ValidationContext) -> rustyline::Result<rustyline::validate::ValidationResult> {
+		let input = ctx.input();
+		let mut shenv_clone = self.shenv.clone();
+		match check_delims(input) && check_keywords(input, &mut shenv_clone) {
+			true => Ok(ValidationResult::Valid(None)),
+			false => Ok(ValidationResult::Incomplete),
+		}
+
+	}
+}