Add to_string to prepare for string interpolation.

This commit is contained in:
Stephen Chung 2020-03-31 10:00:17 +08:00
parent c17dc34f86
commit dcf5eaf64d
6 changed files with 64 additions and 48 deletions

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@ -261,21 +261,23 @@ Values and types
----------------
[`type_of()`]: #values-and-types
[`to_string()`]: #values-and-types
The following primitive types are supported natively:
| Category | Equivalent Rust types | `type_of()` name |
| ----------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | ----------------- |
| **Integer number** | `u8`, `i8`, `u16`, `i16`, <br/>`u32`, `i32` (default for [`only_i32`]),<br/>`u64`, `i64` _(default)_ | _same as type_ |
| **Floating-point number** (disabled with [`no_float`]) | `f32`, `f64` _(default)_ | _same as type_ |
| **Boolean value** | `bool` | `"bool"` |
| **Unicode character** | `char` | `"char"` |
| **Unicode string** | `String` (_not_ `&str`) | `"string"` |
| **Array** (disabled with [`no_index`]) | `rhai::Array` | `"array"` |
| **Object map** (disabled with [`no_object`]) | `rhai::Map` | `"map"` |
| **Dynamic value** (i.e. can be anything) | `rhai::Dynamic` | _the actual type_ |
| **System number** (current configuration) | `rhai::INT` (`i32` or `i64`),<br/>`rhai::FLOAT` (`f32` or `f64`) | _same as type_ |
| **Nothing/void/nil/null** (or whatever you want to call it) | `()` | `"()"` |
| Category | Equivalent Rust types | `type_of()` | `to_string()` |
| ----------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | --------------------- | --------------------- |
| **Integer number** | `u8`, `i8`, `u16`, `i16`, <br/>`u32`, `i32` (default for [`only_i32`]),<br/>`u64`, `i64` _(default)_ | `"i32"`, `"u64"` etc. | `"42"`, `"123"` etc. |
| **Floating-point number** (disabled with [`no_float`]) | `f32`, `f64` _(default)_ | `"f32"` or `"f64"` | `"123.4567"` etc. |
| **Boolean value** | `bool` | `"bool"` | `"true"` or `"false"` |
| **Unicode character** | `char` | `"char"` | `"A"`, `"x"` etc. |
| **Unicode string** | `String` (_not_ `&str`) | `"string"` | `"hello"` etc. |
| **Array** (disabled with [`no_index`]) | `rhai::Array` | `"array"` | `"[ ? ? ? ]"` |
| **Object map** (disabled with [`no_object`]) | `rhai::Map` | `"map"` | `#{ "a": 1, "b": 2 }` |
| **Dynamic value** (i.e. can be anything) | `rhai::Dynamic` | _the actual type_ | _actual value_ |
| **System integer** (current configuration) | `rhai::INT` (`i32` or `i64`) | `"i32"` or `"i64"` | `"42"`, `"123"` etc. |
| **System floating-point** (current configuration, disabled with [`no_float`]) | `rhai::FLOAT` (`f32` or `f64`) | `"f32"` or `"f64"` | `"123.456"` etc. |
| **Nothing/void/nil/null** (or whatever you want to call it) | `()` | `"()"` | `""` _(empty string)_ |
[`Dynamic`]: #values-and-types
[`()`]: #values-and-types
@ -289,7 +291,9 @@ This is useful on some 32-bit systems where using 64-bit integers incurs a perfo
If no floating-point is needed or supported, use the [`no_float`] feature to remove it.
There is a `type_of` function to detect the actual type of a value. This is useful because all variables are `Dynamic`.
The `to_string` function converts a standard type into a string for display purposes.
The `type_of` function detects the actual type of a value. This is useful because all variables are `Dynamic`.
```rust
// Use 'type_of()' to get the actual types of values
@ -315,8 +319,9 @@ Value conversions
[`to_int`]: #value-conversions
[`to_float`]: #value-conversions
There is a `to_float` function to convert a supported number to an `f64`, and a `to_int` function to convert a supported number to `i64` and that's about it.
For other conversions, register custom conversion functions.
The `to_float` function converts a supported number to `FLOAT` (`f32` or `f64`),
and the `to_int` function converts a supported number to `INT` (`i32` or `i64`).
That's about it. For other conversions, register custom conversion functions.
```rust
let x = 42;

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@ -2,7 +2,7 @@
//! _standard library_ of utility functions.
use crate::any::Any;
use crate::engine::Engine;
use crate::engine::{Engine, FUNC_TO_STRING, KEYWORD_DEBUG, KEYWORD_PRINT};
use crate::fn_register::{RegisterDynamicFn, RegisterFn, RegisterResultFn};
use crate::parser::{Position, INT};
use crate::result::EvalAltResult;
@ -561,10 +561,10 @@ impl Engine<'_> {
self.register_fn("==", |_: (), _: ()| true); // () == ()
// Register print and debug
fn debug<T: Debug>(x: T) -> String {
fn to_debug<T: Debug>(x: T) -> String {
format!("{:?}", x)
}
fn print<T: Display>(x: T) -> String {
fn to_string<T: Display>(x: T) -> String {
format!("{}", x)
}
@ -577,30 +577,39 @@ impl Engine<'_> {
)
}
reg_fn1!(self, "print", print, String, INT, bool, char, String);
self.register_fn("print", || "".to_string());
self.register_fn("print", |_: ()| "".to_string());
reg_fn1!(self, "debug", debug, String, INT, bool, char, String, ());
reg_fn1!(self, KEYWORD_PRINT, to_string, String, INT, bool);
reg_fn1!(self, FUNC_TO_STRING, to_string, String, INT, bool);
reg_fn1!(self, KEYWORD_PRINT, to_string, String, char, String);
reg_fn1!(self, FUNC_TO_STRING, to_string, String, char, String);
self.register_fn(KEYWORD_PRINT, || "".to_string());
self.register_fn(KEYWORD_PRINT, |_: ()| "".to_string());
self.register_fn(FUNC_TO_STRING, |_: ()| "".to_string());
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, INT, bool, ());
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, char, String);
#[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))]
{
reg_fn1!(self, "print", print, String, i8, u8, i16, u16);
reg_fn1!(self, "print", print, String, i32, i64, u32, u64);
reg_fn1!(self, "debug", debug, String, i8, u8, i16, u16);
reg_fn1!(self, "debug", debug, String, i32, i64, u32, u64);
reg_fn1!(self, KEYWORD_PRINT, to_string, String, i8, u8, i16, u16);
reg_fn1!(self, FUNC_TO_STRING, to_string, String, i8, u8, i16, u16);
reg_fn1!(self, KEYWORD_PRINT, to_string, String, i32, i64, u32, u64);
reg_fn1!(self, FUNC_TO_STRING, to_string, String, i32, i64, u32, u64);
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, i8, u8, i16, u16);
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, i32, i64, u32, u64);
}
#[cfg(not(feature = "no_float"))]
{
reg_fn1!(self, "print", print, String, f32, f64);
reg_fn1!(self, "debug", debug, String, f32, f64);
reg_fn1!(self, KEYWORD_PRINT, to_string, String, f32, f64);
reg_fn1!(self, FUNC_TO_STRING, to_string, String, f32, f64);
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, f32, f64);
}
#[cfg(not(feature = "no_index"))]
{
self.register_fn("print", |x: &mut Array| -> String { format!("{:?}", x) });
self.register_fn("debug", |x: &mut Array| -> String { format!("{:?}", x) });
reg_fn1!(self, KEYWORD_PRINT, to_debug, String, Array);
reg_fn1!(self, FUNC_TO_STRING, to_debug, String, Array);
reg_fn1!(self, KEYWORD_DEBUG, to_debug, String, Array);
// Register array iterator
self.register_iterator::<Array, _>(|a| {
@ -610,8 +619,15 @@ impl Engine<'_> {
#[cfg(not(feature = "no_object"))]
{
self.register_fn("print", |x: &mut Map| -> String { format!("#{:?}", x) });
self.register_fn("debug", |x: &mut Map| -> String { format!("#{:?}", x) });
self.register_fn(KEYWORD_PRINT, |x: &mut Map| -> String {
format!("#{:?}", x)
});
self.register_fn(FUNC_TO_STRING, |x: &mut Map| -> String {
format!("#{:?}", x)
});
self.register_fn(KEYWORD_DEBUG, |x: &mut Map| -> String {
format!("#{:?}", x)
});
}
}

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@ -42,6 +42,7 @@ pub(crate) const KEYWORD_DEBUG: &str = "debug";
pub(crate) const KEYWORD_DUMP_AST: &str = "dump_ast";
pub(crate) const KEYWORD_TYPE_OF: &str = "type_of";
pub(crate) const KEYWORD_EVAL: &str = "eval";
pub(crate) const FUNC_TO_STRING: &str = "to_string";
pub(crate) const FUNC_GETTER: &str = "get$";
pub(crate) const FUNC_SETTER: &str = "set$";

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@ -12,7 +12,7 @@ fn test_chars() -> Result<(), EvalAltResult> {
assert_eq!(engine.eval::<char>(r#"let x="hello"; x[2]"#)?, 'l');
assert_eq!(
engine.eval::<String>(r#"let y="hello"; y[2]='$'; y"#)?,
"he$lo".to_string()
"he$lo"
);
}

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@ -7,7 +7,7 @@ fn test_increment() -> Result<(), EvalAltResult> {
assert_eq!(engine.eval::<INT>("let x = 1; x += 2; x")?, 3);
assert_eq!(
engine.eval::<String>("let s = \"test\"; s += \"ing\"; s")?,
"testing".to_string()
"testing"
);
Ok(())

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@ -6,30 +6,24 @@ fn test_string() -> Result<(), EvalAltResult> {
assert_eq!(
engine.eval::<String>(r#""Test string: \u2764""#)?,
"Test string: ❤".to_string()
"Test string: ❤"
);
assert_eq!(
engine.eval::<String>(r#""Test string: \x58""#)?,
"Test string: X".to_string()
"Test string: X"
);
assert_eq!(
engine.eval::<String>(r#""foo" + "bar""#)?,
"foobar".to_string()
);
assert_eq!(engine.eval::<String>(r#""foo" + "bar""#)?, "foobar");
#[cfg(not(feature = "no_stdlib"))]
assert_eq!(
engine.eval::<String>(r#""foo" + 123"#)?,
"foo123".to_string()
);
assert_eq!(engine.eval::<String>(r#""foo" + 123"#)?, "foo123");
#[cfg(not(feature = "no_float"))]
#[cfg(not(feature = "no_stdlib"))]
assert_eq!(
engine.eval::<String>(r#""foo" + 123.4556"#)?,
"foo123.4556".to_string()
);
assert_eq!(engine.eval::<String>(r#""foo" + 123.4556"#)?, "foo123.4556");
#[cfg(not(feature = "no_stdlib"))]
assert_eq!(engine.eval::<String>("(42).to_string()")?, "42");
Ok(())
}