Add support for floats with scientific notation

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Scientific notation support for floats.
 - Fixed a bug where comments in list prepending expressions could be formatted
   incorrectly.
 - Fixed a bug where comments in record update expressions could be formatted
@@ -26,8 +27,8 @@
 - Updated following runtime versions set via `gleam new`: `Erlang/OTP`
   to `25.2`, and `Elixir` to `1.14.2`.
 - The formatter now inserts underscores into larger `Int`s and the larger
-  integer parts of `Float`s.
 - Added support for top level TypeScript file inclusion in builds.
+  integer parts of `Float`s.
 - The build tool will now favour using rebar3 over Mix for packages that support
   both. This fixes an issue where some packages could not be compiled without
   Elixir installed even though it is not strictly required.

compiler-core/src/erlang/tests/numbers.rs

@@ -32,3 +32,28 @@ pub fn main() {
 "#
     );
 }
+
+#[test]
+fn numbers_with_scientific_notation() {
+    assert_erl!(
+        r#"
+const i = 100.001e523
+const j = -100.001e-523
+
+const k = 100.001e1_230
+const l = -100.001e-1_230
+
+const m = 100.001e123_456_789
+const n = -100.001e-123_456_789
+
+pub fn main() {
+    i
+    j
+    k
+    l
+    m
+    n
+}
+"#
+    );
+}

compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__numbers__numbers_with_scientific_notation.snap

@@ -0,0 +1,18 @@
+---
+source: compiler-core/src/erlang/tests/numbers.rs
+expression: "\nconst i = 100.001e523\nconst j = -100.001e-523\n\nconst k = 100.001e1_230\nconst l = -100.001e-1_230\n\nconst m = 100.001e123_456_789\nconst n = -100.001e-123_456_789\n\npub fn main() {\n    i\n    j\n    k\n    l\n    m\n    n\n}\n"
+---
+-module(the_app).
+-compile(no_auto_import).
+
+-export([main/0]).
+
+-spec main() -> float().
+main() ->
+    100.001e523,
+    -100.001e-523,
+    100.001e1230,
+    -100.001e-1230,
+    100.001e123456789,
+    -100.001e-123456789.
+

compiler-core/src/format/tests.rs

@@ -1241,6 +1241,43 @@ fn expr_float() {
   -1_234_567.0
   -12_345_678.0
 }
+"#
+    );
+
+    assert_format_rewrite!(
+        r#"fn main() {
+  1.0e1
+  1.0e-1
+  -1.0e1
+  -1.0e-1
+  1.0e10
+  1.0e-10
+  -1.0e10
+  -11.0e-10
+  1.0e100
+  1.0e-100
+  -1.0e100
+  -11.0e-100
+  1.0000e100
+  1.0000e100_100
+}
+"#,
+        r#"fn main() {
+  1.0e1
+  1.0e-1
+  -1.0e1
+  -1.0e-1
+  1.0e10
+  1.0e-10
+  -1.0e10
+  -11.0e-10
+  1.0e100
+  1.0e-100
+  -1.0e100
+  -11.0e-100
+  1.0000e100
+  1.0000e100_100
+}
 "#
     );
 }

compiler-core/src/javascript/tests/numbers.rs

@@ -12,6 +12,14 @@ fn go() {
     0b00001111
     0o17
     0xF
+    0.01e-1
+    0.01e-0
+    -10.01e-1
+    -10.01e-0
+    100.001e523
+    -100.001e-523
+    100.001e123_456_789
+    -100.001e-123_456_789
     1_000
 }
 "#,

compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__numbers__int_literals.snap

@@ -1,7 +1,6 @@
 ---
 source: compiler-core/src/javascript/tests/numbers.rs
-assertion_line: 5
-expression: "\nfn go() {\n    1\n    2\n    -3\n    4001\n    0b00001111\n    0o17\n    0xF\n    1_000\n}\n"
+expression: "\nfn go() {\n    1\n    2\n    -3\n    4001\n    0b00001111\n    0o17\n    0xF\n    0.01e-1\n    0.01e-0\n    -10.01e-1\n    -10.01e-0\n    100.001e523\n    -100.001e-523\n    100.001e123_456_789\n    -100.001e-123_456_789\n    1_000\n}\n"
 ---
 function go() {
   1;
@@ -11,6 +10,14 @@ function go() {
   0b00001111;
   0o17;
   0xF;
+  0.01e-1;
+  0.01e-0;
+  -10.01e-1;
+  -10.01e-0;
+  100.001e523;
+  -100.001e-523;
+  100.001e123_456_789;
+  -100.001e-123_456_789;
   return 1_000;
 }
 

compiler-core/src/parse/lexer.rs

@@ -617,6 +617,18 @@ where
         if self.chr0 == Some('.') {
             value.push(self.next_char().expect("lex_normal_number float"));
             value.push_str(&self.radix_run(10));
+
+            // If scientific:
+            if self.chr0 == Some('e') {
+                value.push(self.next_char().expect("lex_normal_number scientific"));
+                if self.chr0 == Some('-') {
+                    value.push(
+                        self.next_char()
+                            .expect("lex_normal_number scientific negative"),
+                    );
+                }
+                value.push_str(&self.radix_run(10));
+            }
             let end_pos = self.get_pos();
             (start_pos, Token::Float { value }, end_pos)
         } else {

compiler-core/src/type_/tests.rs

@@ -758,6 +758,10 @@ fn simple_exprs() {
     assert_infer!("0xF", "Int");
     assert_infer!("0o11", "Int");
     assert_infer!("0b1010", "Int");
+
+    // scientific notation
+    assert_infer!("6.02e23", "Float");
+    assert_infer!("6.02e-23", "Float");
 }
 
 #[test]

test/language/src/main.gleam

@@ -108,6 +108,45 @@ fn float_tests() -> List(Test) {
     equality_test("Precedence 1", 8.0, 2.0 +. 2.0 *. 3.0),
     equality_test("Precedence 2", 10.0, 2.0 *. { 2.0 +. 3.0 }),
     equality_test("Precedence 3", 12.0, { 2.0 +. 2.0 } *. 3.0),
+
+
+    // scientific notation
+    basic_addition(0.0e0, 0.0, 0.0),
+    basic_addition(0.0, 0.0e0, 0.0),
+    basic_addition(0.0e-0, 0.0, 0.0),
+    basic_addition(0.0, 0.0e-0, 0.0),
+    basic_addition(1.0e3, 1.0, 1001.0),
+    basic_addition(5.0, 1.0e3, 1005.0),
+    basic_addition(1.0e5, -3.0e5, -200000.0),
+    basic_addition(1.0e50, -1.0e50, 0.0),
+    basic_addition(1.0e-3, 1.0, 1.001),
+    basic_addition(5.0, 1.0e-3, 5.001),
+    basic_addition(10.0e-2, -3.0e-2, 0.07),
+
+    basic_subtraction(0.0e0, 0.0, 0.0),
+    basic_subtraction(0.0, 0.0e0, 0.0),
+    basic_subtraction(0.0e-0, 0.0, 0.0),
+    basic_subtraction(0.0, 0.0e-0, 0.0),
+    basic_subtraction(1.0e3, 1.0, 999.0),
+    basic_subtraction(5.0, 1.0e3, -995.0),
+    basic_subtraction(1.0e5, 1.0e5, 0.0),
+    basic_subtraction(1.0e-3, 1.0, -0.999),
+    basic_subtraction(5.0, 1.0e-3, 4.999),
+    basic_subtraction(10.0e-2, -3.0e-2, 0.13),
+
+    basic_multiplication(0.0e0, 0.0, 0.0),
+    basic_multiplication(0.0, 0.0e0, 0.0),
+    basic_multiplication(0.0e-0, 0.0, 0.0),
+    basic_multiplication(0.0, 0.0e-0, 0.0),
+    basic_multiplication(2.0e1, 2.0e1, 400.0),
+    basic_multiplication(1.0e-5, 1.0e5, 1.0),
+    basic_multiplication(2.0e5, 2.0e-5, 4.0),
+    basic_multiplication(2.0e5, 4.0e-4, 80.0),
+    basic_multiplication(2.0e-5, 2.0e5, 4.0),
+    basic_multiplication(2.0e5, 4.0e-5, 8.0),
+    basic_multiplication(-2.0e-5, 2.0e5, -4.0),
+    basic_multiplication(-2.0e5, -4.0e-5, 8.0),
+
   ]
 }