Updated TODO

TODO.md

@@ -1,4 +1,5 @@
 ## Version Bump checklist
+ - TODO: build and publish script
  - update Cargo.toml
  - run cargo test
  - commit
@@ -10,28 +11,22 @@
 
 
 ## Pre-release
- - Fix linelocation (consistent, what does an operator's linelocation mean?)
  - Tuple operations
  - we don't need vectors as arguments to operators
- - Assignment tests
+ - Fix linelocation when evaluating functions
- - Color check is too slow
 
 ## Parser
- - Better error when `sin = 2`
  - Should functions be operators?
  - Binary, hex, octal numbers
 
 
 ## General
+ - Better tests (assignment, many expressions in one context)
  - Optional config file
  - Optional history file
- - daisyrc file
  - Compile to WASM, publish a webapp
  - evaluate straight from command line
- - Auto-push to crates.io
  - Package for debian
- - Faster startup
-
 
 
 ## Internals
@@ -41,7 +36,6 @@
  - Remove rug dependency (too big, incompatible)
 
 ## Math Features
- - Dice
  - Mean, Median, Min
  - Arbitrary base logarithm
  - Derivatives
@@ -49,21 +43,16 @@
  - Complex numbers
  - acot/acoth functions
  - Sums and products with functional arguments
- - Add functions: gcd, inverse mod
+ - Add functions: gcd, inverse mod, dice
 
 ## Prompt
+ - Fix terminal color detection
  - Live syntax/output (like firefox js terminal)
- - Syntax highlight input and output
+ - Syntax highlighting
  - fish-style tab completion
  - Numbered expressions, history recall
- - Color configuration
  - Enable/disable unit sets (defaults?)
  - Consistent unit ordering
- - Better linelocation
-   - we shouldn't need to re-print user input on evaluation errors, red arrows should adjust themselves to the prettyprinted string
- - Backend-independent colorful printing
-   - Better colors in error texts
- - Better substitution. Consistent: when ascii, when unicode?
  - Command to list substitutions
 
 ## Units

src/command/mod.rs

@@ -224,7 +224,7 @@ pub fn do_command(
 			if args.len() != 2 {
 				return FormattedText::new(
 					format!(
-						"[c]{first}[n] [t]takes exactly two arguments.[n]\n\n",
+						"[c]{first}[n] [t]takes exactly one argument.[n]\n\n",
 					)
 				);
 			}

src/context.rs

@@ -126,6 +126,7 @@ impl Context {
 		} else { panic!() }
 	}
 
+	// Can we define a new variable with this name?
 	pub fn valid_varible(&self, s: &str) -> bool {
 		if {
 			Function::from_string(s).is_some() ||
@@ -145,10 +146,17 @@ impl Context {
 		}
 	}
 
+	// Can we get a value fro mthis variable name?
 	pub fn is_varible(&self, s: &str) -> bool {
 		return {
+			(
+				s == "ans" &&
+				self.history.len() != 0
+			) ||
+			(
 				self.valid_varible(s) &&
 				(self.variables.contains_key(s) || self.shadow.contains_key(s))
+			)
 		};
 	}
 

src/parser/expression/expression.rs

@@ -11,6 +11,23 @@ use super::super::LineLocation;
 #[derive(Debug)]
 #[derive(Clone)]
 pub enum Expression {
+	// Meaning of `LineLocation`:
+	//
+	// For Variables, Constants, Quantities, Tuples:
+	// If this expression was parsed, LineLocation is what part of the prompt was parsed to get this expression
+	// If this expression is the result of a calculation, LineLocaion is the sum of the LineLocations of
+	//	all expressions used to make it. In other words, it points to the part of the prompt that was evaluated
+	//	to get this new expression.
+	//
+	// For Operators:
+	// Linelocation points to the operator's position in the prompt.
+	// If this is a function, it points to the function name.
+	// If this is `+`, `!`, or etc, it points to that character.
+	// Operator arguments are NOT included in this linelocation.
+	//
+	//
+	// All the above rules are implemented when parsing and evaluating expressions.
+
 	Variable(LineLocation, String),
 	Quantity(LineLocation, Quantity),
 	Constant(LineLocation, Constant),

src/parser/mod.rs

@@ -35,6 +35,12 @@ pub fn parse_no_context(s: &String) -> Result<Expression, (LineLocation, DaisyEr
 	parse(&Context::new(), s)
 }
 
+
+
+// Substitiution replaces certain string with pretty unicode characters.
+// When it is enabled, ALL input strings are substituted. Variable and
+// operator tokens use the replaced string value. Make sure both the
+// original and the replaced strings are handled correctly by the parser.
 pub fn substitute(context: &Context, s: &String) -> String {
 	if !context.config.enable_substituion { return s.clone(); }
 	let (_, s) = substitute_cursor(context, s, s.chars().count());

src/parser/stage/find_subs.rs

@@ -62,13 +62,13 @@ fn sub_string(s: &str) -> Option<&'static str> {
 }
 
 
-
+// Finds substitutions in an array of tokens.
-
+// Returns new token array and substitution list.
 pub fn find_subs(
 	mut g: VecDeque<Token>,
 ) -> (
-	VecDeque<(LineLocation, String)>,
+	VecDeque<(LineLocation, String)>, // List of substrings to replace (in order)
-	VecDeque<Token>
+	VecDeque<Token> // New token array, with updated strings and linelocations
 ) {
 
 	// Array of replacements
@@ -103,7 +103,7 @@ pub fn find_subs(
 		};
 
 		if target.is_none() {
-			// Even if nothing changed, we need to update token location
+			// Even if nothing changed, we need to update the new token's linelocation
 			let l = t.get_mut_linelocation();
 			*l = LineLocation{pos: l.pos - offset, len: l.len};
 		} else {