From bd4253d6d396fb27d6e5f13a9c94831d0e9ae465 Mon Sep 17 00:00:00 2001
From: jiyinyiyong <jiyinyiyong@gmail.com>
Date: Sun, 19 Sep 2021 03:58:40 +0800
Subject: [PATCH] try stupid nested expression; bump 0.1.1

---
 .github/workflows/publish.yaml |  7 +++--
 .github/workflows/test.yaml    |  7 +++--
 Cargo.toml                     |  2 +-
 README.md                      | 38 ++++++++++++++++++++++++
 examples/nested.cirru          | 14 +++++++++
 src/parser.rs                  | 54 +++++++++++++++++++++++++++++++---
 6 files changed, 111 insertions(+), 11 deletions(-)
 create mode 100644 examples/nested.cirru

diff --git a/.github/workflows/publish.yaml b/.github/workflows/publish.yaml
index 1c03110..ca98626 100644
--- a/.github/workflows/publish.yaml
+++ b/.github/workflows/publish.yaml
@@ -14,9 +14,10 @@ jobs:
         with:
           toolchain: stable
 
-      - run: cargo run examples/hello.cirru
-      - run: cargo run examples/sum.cirru
-      - run: cargo run examples/assert.cirru
+      - run: cargo run -- -S examples/hello.cirru
+      - run: cargo run -- -S examples/sum.cirru
+      - run: cargo run -- -S examples/assert.cirru
+      - run: cargo run -- -S examples/nested.cirru
 
       # - run: cargo test
 
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 23e60a6..97a2c05 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -16,6 +16,7 @@ jobs:
         with:
           toolchain: stable
 
-      - run: cargo run examples/hello.cirru
-      - run: cargo run examples/sum.cirru
-      - run: cargo run examples/assert.cirru
+      - run: cargo run -- -S examples/hello.cirru
+      - run: cargo run -- -S examples/sum.cirru
+      - run: cargo run -- -S examples/assert.cirru
+      - run: cargo run -- -S examples/nested.cirru
diff --git a/Cargo.toml b/Cargo.toml
index 1f071fa..5e0a9da 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "calx_vm"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["jiyinyiyong <jiyinyiyong@gmail.com>"]
 edition = "2018"
 license = "MIT"
diff --git a/README.md b/README.md
index 5ae8c42..fe3a4a6 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,44 @@ calx -S hello.cirru
 calx -D hello.cirru
 ```
 
+### Syntax Sugar
+
+Code of:
+
+```cirru
+fn main ()
+  i.add
+    const 1
+    i.mul
+      const 2
+      const 3
+
+  echo
+    dup
+
+  assert "|expected 7"
+    i.eq
+      const 7
+```
+
+is desugared to:
+
+```cirru
+fn main ()
+  const 2
+  const 3
+  i.mul
+  const 1
+  i.add
+
+  dup
+  echo
+
+  const 7
+  i.eq
+  assert "|expected 7"
+```
+
 ### Instructions
 
 Highly inspired by:
diff --git a/examples/nested.cirru b/examples/nested.cirru
new file mode 100644
index 0000000..8440d18
--- /dev/null
+++ b/examples/nested.cirru
@@ -0,0 +1,14 @@
+
+fn main ()
+  i.add
+    const 1
+    i.mul
+      const 2
+      const 3
+
+  echo
+    dup
+
+  assert "|expected 7"
+    i.eq
+      const 7
diff --git a/src/parser.rs b/src/parser.rs
index ef4fa84..eaf2d37 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -43,11 +43,14 @@ pub fn parse_function(nodes: &[Cirru]) -> Result<CalxFunc, String> {
   let mut ptr_base: usize = 0;
   for (idx, line) in nodes.iter().enumerate() {
     if idx >= 3 {
-      let instrs = parse_instr(ptr_base, line)?;
+      for expanded in extract_nested(line)? {
+        // println!("expanded {}", expanded);
+        let instrs = parse_instr(ptr_base, &expanded)?;
 
-      for instr in instrs {
-        ptr_base += 1;
-        body.push(instr);
+        for instr in instrs {
+          ptr_base += 1;
+          body.push(instr);
+        }
       }
     }
   }
@@ -423,3 +426,46 @@ pub fn parse_types(xs: &Cirru) -> Result<(Vec<CalxType>, Vec<CalxType>), String>
     }
   }
 }
+
+/// rather stupid function to extract nested calls before current call
+/// TODO better have some tests
+pub fn extract_nested(xs: &Cirru) -> Result<Vec<Cirru>, String> {
+  match xs {
+    Cirru::Leaf(x) => Err(format!("not extracting leaf: {}", x)),
+    Cirru::List(ys) => match ys.get(0) {
+      None => Err(String::from("unexpected empty expression")),
+      Some(Cirru::List(zs)) => Err(format!("unexpected nested instruction name: {:?}", zs)),
+      Some(Cirru::Leaf(zs)) => match zs.as_str() {
+        "block" | "loop" => {
+          let mut chunk: Vec<Cirru> = vec![Cirru::Leaf(zs.to_string())];
+          for (idx, y) in ys.iter().enumerate() {
+            if idx > 0 {
+              for e in extract_nested(y)? {
+                chunk.push(e);
+              }
+            }
+          }
+          Ok(vec![Cirru::List(chunk)])
+        }
+        _ => {
+          let mut pre: Vec<Cirru> = vec![];
+          let mut chunk: Vec<Cirru> = vec![Cirru::Leaf(zs.to_string())];
+          for (idx, y) in ys.iter().enumerate() {
+            if idx > 0 {
+              match y {
+                Cirru::Leaf(_) => chunk.push(y.to_owned()),
+                Cirru::List(_) => {
+                  for e in extract_nested(y)? {
+                    pre.push(e);
+                  }
+                }
+              }
+            }
+          }
+          pre.push(Cirru::List(chunk));
+          Ok(pre)
+        }
+      },
+    },
+  }
+}