From f11232662039d8e0b6119210788c313479bfd760 Mon Sep 17 00:00:00 2001
From: Mark <mark@betalupi.com>
Date: Thu, 6 Apr 2023 09:51:14 -0700
Subject: [PATCH] Added support for unary +

---
 README.md              |  1 -
 src/parser/groupify.rs | 13 ++++++++-----
 src/parser/mod.rs      |  2 ++
 src/parser/tokenize.rs |  9 +++++----
 4 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 3f91d1e..071df4d 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,6 @@ This is nowhere near complete. Stay tuned.
 # TODO
 
 ## Before For 1.0 release
- - `+` as a unary operator
  - Commands
  - Documentation (usage)
  - Documentation (comments)
diff --git a/src/parser/groupify.rs b/src/parser/groupify.rs
index 17bfdd0..2fa4d76 100644
--- a/src/parser/groupify.rs
+++ b/src/parser/groupify.rs
@@ -7,13 +7,12 @@ use crate::parser::ParserError;
 use crate::tokens::Operator;
 
 
-// Turn `-` into `neg`,
-// put `neg`s inside numbers.
-fn lookback_negatives(
+fn lookback_signs(
 	g: &mut VecDeque<PreToken>
 ) -> Result<(), (LineLocation, ParserError)> {
 
 	// Convert `-` operators to `neg` operators
+	// Delete `+`s that mean "positive" instead of "add"
 	let mut i: usize = 0;
 	while i < g.len() {
 		if i == 0 {
@@ -23,7 +22,7 @@ fn lookback_negatives(
 				=> {
 					if o == "-" {
 						g.insert(i, PreToken::PreOperator(*l, String::from("neg")));
-					} else { g.insert(i, a); }
+					} else if o != "+" { g.insert(i, a); }
 				},
 				_ => { g.insert(i, a); }
 			};
@@ -46,6 +45,10 @@ fn lookback_negatives(
 					} {
 						g.insert(i-1, PreToken::PreOperator(*l, String::from("neg")));
 						g.insert(i-1, a);
+					} else if sb == "+" {
+						g.insert(i-1, a);
+						i -= 1; // g is now shorter, we don't need to advance i.
+						// This nullifies the i += 1 at the end of the loop.
 					} else { g.insert(i-1, b); g.insert(i-1, a); }
 				},
 
@@ -104,7 +107,7 @@ fn lookback(
 	g: &mut VecDeque<PreToken>
 ) -> Result<(), (LineLocation, ParserError)> {
 
-	lookback_negatives(g)?;
+	lookback_signs(g)?;
 
 
 	let mut i: usize = 0;
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index eb8b404..7635733 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -155,8 +155,10 @@ pub fn parse(
 	let tokens = tokenize(s);
 	let (_, tokens) = find_subs(tokens);
 	let g = groupify(tokens)?;
+	println!("{:#?}", g);
 	let g = treeify(g)?;
 
+
 	return Ok(g);
 }
 
diff --git a/src/parser/tokenize.rs b/src/parser/tokenize.rs
index 789676d..969f861 100644
--- a/src/parser/tokenize.rs
+++ b/src/parser/tokenize.rs
@@ -103,7 +103,7 @@ pub(in crate::parser) fn tokenize(input: &String) -> VecDeque<PreToken> {
 			// The minus sign also needs special treatment.
 			// It can be the `neg` operator, the `minus` operator,
 			// or it can specify a negative exponent.
-			'-' => {
+			'-' | '+' => {
 				match &mut t {
 					Some(PreToken::PreNumber(_, val)) => {
 						if &val[val.len()-1..] == "e" {
@@ -117,16 +117,17 @@ pub(in crate::parser) fn tokenize(input: &String) -> VecDeque<PreToken> {
 							push_token(&mut g, t, i);
 							t = Some(PreToken::PreOperator(
 								LineLocation{pos: i, len: 1},
-								String::from("-")
+								String::from(c)
 							));
 						}
 					},
 
+					// This may be a negative or a subtraction
 					_ => {
 						push_token(&mut g, t, i);
 						t = Some(PreToken::PreOperator(
 							LineLocation{pos: i, len: 1},
-							String::from("-")
+							String::from(c)
 						));
 					}
 				};
@@ -134,7 +135,7 @@ pub(in crate::parser) fn tokenize(input: &String) -> VecDeque<PreToken> {
 
 			// Operator
 			'*'|'×'|'/'|'÷'|
-			'+'|'^'|'!'|'%'
+			'^'|'!'|'%'
 			=> {
 				match &mut t {
 					Some(PreToken::PreOperator(_, val)) => { val.push(c); },