similarly crude javascript output

3 files changed, 69 insertions, 1 deletions

diff --git a/src/bin/mt-tool.rs b/src/bin/mt-tool.rs
index 8aac6ca..7dab194 100644
--- a/src/bin/mt-tool.rs
+++ b/src/bin/mt-tool.rs
@@ -5,6 +5,7 @@ extern crate getopts;
 
 use modelthing::modelica_parser;
 use modelthing::transpile_scheme::TranspileScheme;
+use modelthing::transpile_js::TranspileJS;
 use getopts::Options;
 use std::env;
 use std::io::Read;
@@ -82,7 +83,7 @@ fn main() {
     let cmd = matches.free[0].clone();
     match cmd.as_str() {
         "parse" => { parse_modelica_files(matches.free[1..].iter().map(|x| x.to_string()).collect()); },
-        "transpile" => {
+        "transpile_scheme" => {
             if matches.free.len() != 2 {
                 println!("Expected a single path to load");
                 exit(-1);
@@ -90,6 +91,14 @@ fn main() {
             let me = modelthing::load_model_entry(Path::new(&matches.free[1])).unwrap();
             println!("{}", me.ast.repr_scheme().unwrap());
         },
+        "transpile_js" => {
+            if matches.free.len() != 2 {
+                println!("Expected a single path to load");
+                exit(-1);
+            }
+            let me = modelthing::load_model_entry(Path::new(&matches.free[1])).unwrap();
+            println!("{}", me.ast.repr_js().unwrap());
+        },
         "list" => {
             // XXX: search path?
             for m in modelthing::search_models(Path::new("examples")) {
diff --git a/src/lib.rs b/src/lib.rs
index e6b2f41..2a098ee 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,6 +7,7 @@ extern crate toml;
 pub mod modelica_parser;
 pub mod modelica_ast;
 pub mod transpile_scheme;
+pub mod transpile_js;
 
 use std::path::Path;
 use std::fs;
diff --git a/src/transpile_js.rs b/src/transpile_js.rs
new file mode 100644
index 0000000..1ec9a10
--- /dev/null
+++ b/src/transpile_js.rs
@@ -0,0 +1,58 @@
+
+use modelica_ast::*;
+
+pub trait TranspileJS {
+    fn repr_js(&self) -> Result<String, String>;
+}
+
+
+impl TranspileJS for ModelicaModel {
+    fn repr_js(&self) -> Result<String, String> {
+        let mut constants = vec![];
+        for (c, e) in self.get_constant_vars() {
+            constants.push(format!("var {} = {};",
+                c, try!(e.repr_js())));
+        }
+        let mut binds = vec![];
+        let mut outputs = vec![];
+        for eq in self.equations.iter() {
+            if let Expr::Ident(ref symb) = eq.lhs {
+                binds.push(format!("var {} = {};",
+                    symb,
+                    try!(eq.rhs.repr_js())));
+                outputs.push(symb.to_string());
+            } else {
+                return Err("Expected an identifier on LHS (in this partial implementation)".to_string())
+            }
+        }
+        Ok(format!(
+        r#"function {slug}({args}) {{
+                {constants}
+                {binds}
+                return [{outputs}];
+        }}"#,
+            slug = "f",
+            args = self.get_free_vars().join(", "),
+            constants = constants.join("\n    "),
+            binds = binds.join("\n    "),
+            outputs = outputs.join(", ")))
+    }
+}
+
+impl TranspileJS for Expr {
+    fn repr_js(&self) -> Result<String, String> {
+        use modelica_ast::Expr::*;
+        match *self {
+            Integer(e) => Ok(format!("{}", e)),
+            Float(e) => Ok(format!("{}", e)),
+            Ident(ref e) => Ok(format!("{}", e)),
+            Der(ref e) => Ok(format!("der({})", try!(e.repr_js()))),
+            Abs(ref e) => Ok(format!("abs({})", try!(e.repr_js()))),
+            BinExpr(op, ref l, ref r) =>
+                Ok(format!("({} {:?} {})",
+                    try!(l.repr_js()),
+                    op,
+                    try!(r.repr_js()))),
+        }
+    }
+}