mers_lib to 0.5.0, readme updated

README.md

@@ -1,93 +1,68 @@
 # mers
 
-Mers is a high-level programming language.
+See [mers/README.md]
-It is designed to be safe (it doesn't crash at runtime) and as simple as possible.
 
-Install from *crates.io*:
+---
-
-```sh
-cargo install mers
-```
-
-See also:
-[Quickstart](Quickstart.md)
-
-## what makes it special
-
-### Simplicity
-
-Mers is simple. There are only few expressions:
-
-- Values (`1`, `"my string"`, ...)
-- Blocks (`{}`)
-- Tuples (`()`) and Objects (`{}`)
-- Assignments (`=`)
-- Variable initializations (`:=`)
-- Variables (`my_var`, `&my_var`)
-- If statements (`if <condition> <then> [else <else>]`)
-- Functions (`arg -> <do something>`)
-- Function calls `arg.function` or `arg1.function(arg2, arg3)` (= `(arg1, arg2, arg3).function`)
-
-Everything else is implemented as a function.
-
-### Types and Safety
-
-Mers is built around a type-system where a value could be one of multiple types.
-```
-x := if condition { 12 } else { "something went wrong" }
-```
-
-In mers, the compiler tracks all the types in your program,
-and it will catch every possible crash before the program even runs:
-If we tried to use `x` as an int, the compiler would complain since it might be a string, so this **does not compile**:
 
 ```
-list := (1, 2, if true 3 else "not an int")
+"Hello, World!".println
-list.sum.println
 ```
 
-Type-safety for functions is different from what you might expect.
+> `Hello, Variable!`
-You don't need to tell mers what type your function's argument has - you just use it however you want as if mers was a dynamically typed language:
+
+---
 
 ```
-sum_doubled := iter -> {
+my_var := "Hello, Variable!"
-  one := iter.sum
+my_var.println
-  (one, one).sum
-}
-(1, 2, 3).sum_doubled.println
 ```
 
-We could try to use the function improperly by passing a string instead of an int:
+> `Hello, Variable!`
+
+---
 
 ```
-(1, 2, "3").sum_doubled.println
+(1, 2, 3, 4).sum.println
 ```
 
-But mers will catch this and show an error, because the call to `sum` inside of `sum_doubled` would fail.
+> `10`
 
-### Error Handling
+---
-
-Errors in mers are normal values.
-For example, `("ls", ("/")).run_command` has the return type `({Int/()}, String, String)/RunCommandError`.
-This means it either returns the result of the command (exit code, stdout, stderr) or an error (a value of type `RunCommandError`).
-
-So, if we want to print the programs stdout, we could try
 
 ```
-(s, stdout, stderr) := ("ls", ("/")).run_command
+(1, "2", 3, 4).sum.println
-stdout.println
 ```
 
-But if we encountered a `RunCommandError`, mers wouldn't be able to assign the value to `(s, stdout, stderr)`, so this doesn't compile.
+---
-Instead, we need to handle the error case, using the `try` function:
 
 ```
-("ls", ("/")).run_command.try((
+(1, 2, 3, 4).as_list.debug
-  (s, stdout, stderr) -> stdout.println,
-  error -> error.println,
-))
 ```
 
-## docs
+> `List<Int> :: [1, 2, 3, 4]`
 
-docs will be available in some time. for now, check mers_lib/src/program/configs/*
+---
+
+```
+(1.0, 2.0).as_list.debug
+```
+
+> `List<Float> :: [1, 2]`
+
+---
+
+```
+(1, 2, 3.5).as_list.debug
+```
+
+> `List<Int/Float> :: [1, 2, 3.5]`
+
+---
+
+```
+int_list := (1, 2, 3).as_list
+float_list := (4.5, 6.0).as_list
+int_list.chain(float_list).as_list.debug
+```
+
+> `List<Int/Float> :: [1, 2, 3, 4.5, 6]`

mers_lib/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mers_lib"
-version = "0.4.0"
+version = "0.5.0"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "library to use the mers language in other projects"

mers_lib/README.md

@@ -3,5 +3,47 @@
 The library behind [mers](https://github.com/Dummi26/mers).
 
 With this, you can parse, compile, check and run mers code.
-
 You can also add your own functions and types which can then be used from mers, if you really want to.
+
+## Running mers
+
+There are four steps to running mers code.
+The examples show you how to actually implement them,
+this readme only explains what they do any why.
+
+### 1. Parsing
+
+This first step converts the source code, a string, to a parsed mers statement.
+
+In this step, syntax errors and unknown variables are caught.
+
+### 2. Compiling
+
+This converts a parsed mers statement to a compiled one. It almost never produces an error.
+
+### 3. Checking
+
+This step is optional. If you parse and compile your source code, you can (try to) run it.
+However, mers assumes that all mers code you run is actually valid,
+so if you don't check your codes validity, mers will probably panic while running your code.
+
+This step performs all the type-checking and determines the output type of your code, if it is valid.
+
+For example, the following code is valid and has the return type `Int/Float`:
+
+```
+my_condition := true
+
+if my_condition {
+  5
+} else {
+  1.4
+}
+```
+
+### 4. Running
+
+This step assumes that the code it is running is actually valid, so it never returns an error.
+As long as `check` didn't return an error in Step 3, it is safe to assume that this will return the value produced by the code.
+We can also assume that the return value has a type which is included in that determined by `check`.
+If `check` returned an error, this will likely panic.

mers_lib/examples/01_user_scripts.rs

@@ -35,23 +35,14 @@ fn main() -> Result<(), CheckError> {
     Ok(())
 }
 
+/// example 00
 fn parse_compile_check_run(src: String) -> Result<(Type, Data), CheckError> {
-    // prepare the string for parsing
     let mut source = Source::new_from_string(src);
-    // this is used for error messages
     let srca = Arc::new(source.clone());
-    // parse the code
     let parsed = parse(&mut source, &srca)?;
-    // get infos
     let (mut i1, mut i2, mut i3) = Config::new().bundle_std().infos();
-    // compile
     let compiled = parsed.compile(&mut i1, CompInfo::default())?;
-    // check (this step is optional, but if it is skipped when it would have returned an error, `run` will likely panic)
     let output_type = compiled.check(&mut i3, None)?;
-    // run
     let output_value = compiled.run(&mut i2);
-    // check that the predicted output type was correct
-    assert!(output_value.get().as_type().is_included_in(&output_type));
-    // return the produced value
     Ok((output_type, output_value))
 }

mers_lib/src/data/function.rs

@@ -23,6 +23,18 @@ pub struct Function {
     )>,
 }
 impl Function {
+    pub fn new(
+        out: impl Fn(&Type) -> Result<Type, CheckError> + Send + Sync + 'static,
+        run: impl Fn(Data) -> Data + Send + Sync + 'static,
+    ) -> Self {
+        Self {
+            info: Arc::new(crate::info::Info::neverused()),
+            info_check: Arc::new(Mutex::new(crate::info::Info::neverused())),
+            out: Arc::new(move |a, _| out(a)),
+            run: Arc::new(move |a, _| run(a)),
+            inner_statements: None,
+        }
+    }
     pub fn with_info_run(&self, info: Arc<Info>) -> Self {
         Self {
             info,