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authorNerdyPepper <[email protected]>2019-03-23 05:12:45 +0000
committerNerdyPepper <[email protected]>2019-03-23 05:12:45 +0000
commited0d484e0f1a76bded753877122f9807211fe969 (patch)
tree71d8048844d8d017c797e73fe8141cf75b27c812 /src/lex
parentde4c9d0cc54b60b4ff7bef568f3643bdbbbf22f4 (diff)
use dirty precedence hack to fix unary once and for all
Diffstat (limited to 'src/lex')
-rw-r--r--src/lex/mod.rs11
1 files changed, 7 insertions, 4 deletions
diff --git a/src/lex/mod.rs b/src/lex/mod.rs
index a4ea952..9912ca3 100644
--- a/src/lex/mod.rs
+++ b/src/lex/mod.rs
@@ -70,6 +70,7 @@ fn get_functions() -> HashMap<&'static str, Token> {
70 ("sqrt", Function::token_from_fn("sqrt".into(), |x| x.sqrt())), 70 ("sqrt", Function::token_from_fn("sqrt".into(), |x| x.sqrt())),
71 ("ceil", Function::token_from_fn("ceil".into(), |x| x.ceil())), 71 ("ceil", Function::token_from_fn("ceil".into(), |x| x.ceil())),
72 ("floor", Function::token_from_fn("floor".into(), |x| x.floor())), 72 ("floor", Function::token_from_fn("floor".into(), |x| x.floor())),
73 // single arg functions can be added here
73 ].iter().cloned().collect(); 74 ].iter().cloned().collect();
74} 75}
75 76
@@ -79,7 +80,7 @@ fn get_operators() -> HashMap<char, Token> {
79 ('-', Operator::token_from_op('-', |x, y| x - y, 2, true)), 80 ('-', Operator::token_from_op('-', |x, y| x - y, 2, true)),
80 ('*', Operator::token_from_op('*', |x, y| x * y, 3, true)), 81 ('*', Operator::token_from_op('*', |x, y| x * y, 3, true)),
81 ('/', Operator::token_from_op('/', |x, y| x / y, 3, true)), 82 ('/', Operator::token_from_op('/', |x, y| x / y, 3, true)),
82 ('^', Operator::token_from_op('^', |x, y| x.powf(y) , 4, true)), 83 ('^', Operator::token_from_op('^', |x, y| x.powf(y) , 4, false)),
83 ].iter().cloned().collect(); 84 ].iter().cloned().collect();
84} 85}
85 86
@@ -123,7 +124,7 @@ pub fn lexer(input: &str) -> Result<Vec<Token>, String> {
123 result.push(Token::LParen); 124 result.push(Token::LParen);
124 result.push(Token::Num((letter.to_string() + "1").parse::<f64>().unwrap())); 125 result.push(Token::Num((letter.to_string() + "1").parse::<f64>().unwrap()));
125 result.push(Token::RParen); 126 result.push(Token::RParen);
126 result.push(operators.get(&'*').unwrap().clone()); 127 result.push(Operator::token_from_op('*', |x, y| x * y, 10, true));
127 } 128 }
128 }, 129 },
129 '/' | '*' | '^' => { 130 '/' | '*' | '^' => {
@@ -132,6 +133,8 @@ pub fn lexer(input: &str) -> Result<Vec<Token>, String> {
132 result.push(operator_token); 133 result.push(operator_token);
133 last_char_is_op = true; // 5 / -5 134 last_char_is_op = true; // 5 / -5
134 // ^---- unary 135 // ^---- unary
136 // TODO: parse right associative followed by unary properly
137 // 2^+5 is parsed as 2^1*5 = 10
135 }, 138 },
136 '(' => { 139 '(' => {
137 if char_vec.len() > 0 { 140 if char_vec.len() > 0 {
@@ -161,7 +164,8 @@ pub fn lexer(input: &str) -> Result<Vec<Token>, String> {
161 result.push(Token::LParen); 164 result.push(Token::LParen);
162 last_char_is_op = true; // unary + or - if a lparen was encountered 165 last_char_is_op = true; // unary + or - if a lparen was encountered
163 // (-5 + 6) or (+6 + 7) 166 // (-5 + 6) or (+6 + 7)
164 // ^-----------^-----unary 167 // ^ ^
168 // `-----------`----unary
165 }, 169 },
166 ')' => { 170 ')' => {
167 drain_num_stack(&mut num_vec, &mut result); 171 drain_num_stack(&mut num_vec, &mut result);
@@ -177,7 +181,6 @@ pub fn lexer(input: &str) -> Result<Vec<Token>, String> {
177 } 181 }
178 } 182 }
179 drain_num_stack(&mut num_vec, &mut result); 183 drain_num_stack(&mut num_vec, &mut result);
180 println!("{:?}", result);
181 Ok(result) 184 Ok(result)
182} 185}
183 186