feat: implement floating-point number literal parsing and arithmetic operations

Add support for floating-point number literals in the parser by detecting decimal points with trailing digits in `readNumber()`, and switch the compiler's `number()` function from `strtol` to `strtod` for proper double conversion. Update the `num_abs` primitive to use `fabs()` instead of manual negation. Extend test coverage across arithmetic, comparison, equality, modulus, and string conversion tests with floating-point cases, and add a new test for decimal point at end-of-file error detection.

test/decimel_point_at_eof.wren

@@ -0,0 +1,2 @@
+// expect error line 2
+123.

test/number_abs.wren

@@ -2,5 +2,5 @@ io.write(123.abs)    // expect: 123
 io.write(-123.abs)   // expect: 123
 io.write(0.abs)      // expect: 0
 io.write(-0.abs)     // expect: 0
-
-// TODO(bob): Floating point numbers.
+io.write(-0.12.abs)  // expect: 0.12
+io.write(12.34.abs)  // expect: 12.34

test/number_comparison.wren

@@ -15,3 +15,4 @@ io.write(2 >= 2)    // expect: true
 io.write(2 >= 1)    // expect: true
 
 // TODO(bob): Wrong type for RHS.
+// TODO(bob): Comparing zero and negative zero.

test/number_divide.wren

@@ -1,5 +1,5 @@
-io.write(8 / 2) // expect: 4
+io.write(8 / 2)        // expect: 4
+io.write(12.34 / -0.4) // expect: -30.85
 
-// TODO(bob): Floating point numbers.
 // TODO(bob): Unsupported RHS types.
 // TODO(bob): Divide by zero.

test/number_equality.wren

@@ -1,6 +1,7 @@
 io.write(123 == 123)  // expect: true
 io.write(123 == 124)  // expect: false
 io.write(-3 == 3)     // expect: false
+io.write(0 == -0)     // expect: true
 
 // Not equal to other types.
 io.write(123 == "123") // expect: false
@@ -10,10 +11,9 @@ io.write(0 == false)   // expect: false
 io.write(123 != 123)  // expect: false
 io.write(123 != 124)  // expect: true
 io.write(-3 != 3)     // expect: true
+io.write(0 != -0)     // expect: false
 
 // Not equal to other types.
 io.write(123 != "123") // expect: true
 io.write(1 != true)    // expect: true
 io.write(0 != false)   // expect: true
-
-// TODO(bob): Should 0 == -0?

test/number_literals.wren

@@ -1,6 +1,10 @@
-io.write(123)    // expect: 123
-io.write(987654) // expect: 987654
-io.write(0)      // expect: 0
-io.write(-0)     // expect: 0
+io.write(123)     // expect: 123
+io.write(987654)  // expect: 987654
+io.write(0)       // expect: 0
+io.write(-0)      // expect: -0
 
-// TODO(bob): Floating point numbers.
+io.write(123.456) // expect: 123.456
+io.write(-0.001)  // expect: -0.001
+
+// TODO(bob): Hex? Scientific notation?
+// TODO(bob): Literals at and beyond numeric limits.

test/number_minus.wren

@@ -1,5 +1,5 @@
-io.write(5 - 3) // expect: 2
-io.write(3 - 2 - 1) // expect: 0
+io.write(5 - 3)      // expect: 2
+io.write(3.1 - 0.24) // expect: 2.86
+io.write(3 - 2 - 1)  // expect: 0
 
-// TODO(bob): Floating point numbers.
 // TODO(bob): Unsupported RHS types.

test/number_mod.wren

@@ -3,10 +3,12 @@ io.write(10 % 5) // expect: 0
 io.write(-4 % 3) // expect: -1
 io.write(4 % -3) // expect: 1
 io.write(-4 % -3) // expect: -1
+io.write(-4.2 % 3.1) // expect: -1.1
+io.write(4.2 % -3.1) // expect: 1.1
+io.write(-4.2 % -3.1) // expect: -1.1
 
 // Left associative.
 io.write(13 % 7 % 4) // expect: 2
 
-// TODO(bob): Floating point numbers.
 // TODO(bob): Unsupported RHS types.
 // TODO(bob): Error on mod by zero.

test/number_multiply.wren

@@ -1,4 +1,4 @@
 io.write(5 * 3) // expect: 15
+io.write(12.34 * 0.3) // expect: 3.702
 
-// TODO(bob): Floating point numbers.
 // TODO(bob): Unsupported RHS types.

test/number_plus.wren

@@ -1,4 +1,5 @@
+io.write(1 + 2) // expect: 3
+io.write(12.34 + 0.13) // expect: 12.47
 io.write(3 + 5 + 2) // expect: 10
 
-// TODO(bob): Floating point numbers.
 // TODO(bob): Unsupported RHS types.

test/number_to_string.wren

@@ -1,5 +1,5 @@
 io.write(123.toString == "123") // expect: true
 io.write(-123.toString == "-123") // expect: true
-io.write(-0.toString == "0") // expect: true
-
-// TODO(bob): Floating point numbers.
+io.write(-0.toString == "-0") // expect: true
+io.write(12.34.toString == "12.34") // expect: true
+io.write(-0.0001.toString == "-0.0001") // expect: true