Added badges; updated README with API example

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "phoron_asm"
 description = "A Jasmin-compatible Assembler for the JVM"
-version = "1.0.0"
+version = "1.0.1"
 authors = ["Timmy Jose"]
 homepage = "https://github.com/oyi-lang/phoron_asm"
 documentation = "https://docs.rs/phoron_asm/1.0.0/phoron_asm/"
@@ -19,5 +19,5 @@ path = "src/main.rs"
 
 [dependencies]
 
-phoron_core = "0.5.3"
+phoron_core = "0.5.4"
 

README.md

@@ -1,5 +1,10 @@
 # phoron_asm
 
+![github workflow](https://github.com/oyi-lang/phoron_asm/actions/workflows/rust.yml/badge.svg)
+[<img alt="crates.io" src="https://img.shields.io/crates/v/phoron_asm.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/phoron_asm)
+[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-phoron_asm-3052218?style=for-the-badge&labelColor=555555&logo=docs.rs" height="20">](https://docs.rs/phoron_asm)
+
+
 This project defines `Phoron`, a [Jasmin](https://jasmin.sourceforge.net/)-compatible assembler for the [JVM Instruction Set.](https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html).
 
 For the specification, please refer to the [specification document](doc/Specification.md).
@@ -119,3 +124,149 @@ Hello, world
 
 ```
 
+
+## Sample API usage
+
+The same example, but using the API instead.
+
+
+```
+use std::{
+    error::Error,
+    fmt, fs,
+    io::BufWriter,
+    path::{Path, PathBuf},
+};
+
+use phoron_asm::{
+    codegen::Codegen, cp_analyzer::ConstantPoolAnalyzer, lexer::Lexer, parser::Parser,
+    sourcefile::SourceFile,
+};
+
+#[derive(Debug)]
+pub struct RunError {
+    message: String,
+}
+
+impl Error for RunError {}
+
+impl fmt::Display for RunError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+fn process_file(src_file: &PathBuf) -> Result<(), Box<dyn std::error::Error>> {
+    let outfile = src_file.with_extension("class");
+
+    let source_file = SourceFile::new(src_file).map_err(|err| RunError {
+        message: err.to_string(),
+    })?;
+    let mut parser = Parser::new(Lexer::new(&source_file));
+    let ast = parser.parse().unwrap();
+
+    if parser.errored() {
+        return Err(Box::new(RunError {
+            message: "errors encountered during parsing and typ-checking".into(),
+        }));
+    }
+
+    let mut cp_analyzer = ConstantPoolAnalyzer::new();
+    let cp = cp_analyzer.analyze(&ast).map_err(|err| RunError {
+        message: err.to_string(),
+    })?;
+
+    let mut outfile_w = BufWriter::new(fs::File::create(&outfile)?);
+    let mut codegen = Codegen::new(&mut outfile_w);
+    codegen.gen_bytecode(&ast, &cp).map_err(|err| RunError {
+        message: err.to_string(),
+    })?;
+
+    Ok(())
+}
+
+fn main() {
+    let src_file = Path::new("./samples/").join("HelloWorld.pho");
+    match process_file(&src_file) {
+        Err(err) => eprintln!("{err}"),
+        Ok(_) => println!("Class file generated"),
+    }
+}
+
+```
+
+Running it:
+
+```
+$ cargo run --release
+Class file generated
+
+:$ javap -v samples/HelloWorld.class
+Classfile /Users/z0ltan/dev/playground/phoron_asm_demo/samples/HelloWorld.class
+  Last modified 19-Mar-2023; size 389 bytes
+  SHA-256 checksum 533a66c051831cba84a32b20d38c4bb20d68b78aabc137d7c7fb3cc864ff8bf9
+  Compiled from "./samples/HelloWorld.pho"
+public class HelloWorld
+  minor version: 3
+  major version: 45
+  flags: (0x0021) ACC_PUBLIC, ACC_SUPER
+  this_class: #4                          // HelloWorld
+  super_class: #6                         // java/lang/Object
+  interfaces: 0, fields: 0, methods: 2, attributes: 1
+Constant pool:
+   #1 = Utf8               SourceFile
+   #2 = Utf8               ./samples/HelloWorld.pho
+   #3 = Utf8               HelloWorld
+   #4 = Class              #3             // HelloWorld
+   #5 = Utf8               java/lang/Object
+   #6 = Class              #5             // java/lang/Object
+   #7 = Utf8               <init>
+   #8 = Utf8               ()V
+   #9 = Utf8               Code
+  #10 = NameAndType        #7:#8          // "<init>":()V
+  #11 = Methodref          #6.#10         // java/lang/Object."<init>":()V
+  #12 = Utf8               main
+  #13 = Utf8               ([Ljava/lang/String;)V
+  #14 = Utf8               java/lang/System
+  #15 = Class              #14            // java/lang/System
+  #16 = Utf8               out
+  #17 = Utf8               Ljava/io/PrintStream;
+  #18 = NameAndType        #16:#17        // out:Ljava/io/PrintStream;
+  #19 = Fieldref           #15.#18        // java/lang/System.out:Ljava/io/PrintStream;
+  #20 = Utf8               Hello, world
+  #21 = String             #20            // Hello, world
+  #22 = Utf8               java/io/PrintStream
+  #23 = Class              #22            // java/io/PrintStream
+  #24 = Utf8               println
+  #25 = Utf8               (Ljava/lang/String;)V
+  #26 = NameAndType        #24:#25        // println:(Ljava/lang/String;)V
+  #27 = Methodref          #23.#26        // java/io/PrintStream.println:(Ljava/lang/String;)V
+{
+  public HelloWorld();
+    descriptor: ()V
+    flags: (0x0001) ACC_PUBLIC
+    Code:
+      stack=1, locals=1, args_size=1
+         0: aload_0
+         1: invokespecial #11                 // Method java/lang/Object."<init>":()V
+         4: return
+
+  public static void main(java.lang.String[]);
+    descriptor: ([Ljava/lang/String;)V
+    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
+    Code:
+      stack=2, locals=1, args_size=1
+         0: getstatic     #19                 // Field java/lang/System.out:Ljava/io/PrintStream;
+         3: ldc           #21                 // String Hello, world
+         5: invokevirtual #27                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
+         8: return
+}
+SourceFile: "./samples/HelloWorld.pho"
+
+~/dev/playground/phoron_asm_demo:$ java -cp "./samples" HelloWorld
+Hello, world
+
+```
+
+
+