feat: Add a setting to strip indentation from the generated grammar

lalrpop-test/src/lib.rs

@@ -927,6 +927,7 @@ fn verify_lalrpop_generates_itself() {
         Command::new("../target/debug/lalrpop")
             .args(&[
                 "--force",
+                "--no-whitespace",
                 "--out-dir",
                 out_dir,
                 copied_grammar_file

lalrpop/src/api/mod.rs

@@ -103,6 +103,13 @@ impl Configuration {
         self
     }
 
+    /// If false, shrinks the generated code by removing redundant white space.
+    /// Default is true.
+    pub fn emit_whitespace(&mut self, val: bool) -> &mut Configuration {
+        self.session.emit_whitespace = val;
+        self
+    }
+
     /// If true, emit report file about generated code.
     pub fn emit_report(&mut self, val: bool) -> &mut Configuration {
         self.session.emit_report = val;

lalrpop/src/main.rs

@@ -51,6 +51,10 @@ fn main1() -> io::Result<()> {
         config.emit_comments(true);
     }
 
+    if args.flag_no_whitespace {
+        config.emit_whitespace(false);
+    }
+
     if args.flag_report {
         config.emit_report(true);
     }
@@ -101,6 +105,7 @@ Options:
     --features FEATURES  Comma separated list of features for conditional compilation.
     -f, --force          Force execution, even if the .lalrpop file is older than the .rs file.
     -c, --color          Force colorful output, even if this is not a TTY.
+    --no-whitespace      Removes redundant whitespace from the generated file. (Default: false)
     --comments           Enable comments in the generated code.
     --report             Generate report files.
 ";
@@ -114,6 +119,7 @@ struct Args {
     flag_force: bool,
     flag_color: bool,
     flag_comments: bool,
+    flag_no_whitespace: bool,
     flag_report: bool,
     flag_version: bool,
 }
@@ -181,4 +187,13 @@ mod test {
             .unwrap();
         assert_eq!(args.flag_features, Some("test,abc".to_string()));
     }
+
+    #[test]
+    fn emit_whitespace() {
+        let argv = || vec!["lalrpop", "--no-whitespace", "file.lalrpop"];
+        let args: Args = Docopt::new(USAGE)
+            .and_then(|d| d.argv(argv().into_iter()).deserialize())
+            .unwrap();
+        assert!(args.flag_no_whitespace, true);
+    }
 }

lalrpop/src/rust/mod.rs

@@ -53,11 +53,15 @@ impl<W: Write> RustWrite<W> {
     }
 
     fn write_indentation(&mut self) -> io::Result<()> {
-        write!(self.write, "{0:1$}", "", self.indent)
+        if Tls::session().emit_whitespace {
+            write!(self.write, "{0:1$}", "", self.indent)?;
+        }
+        Ok(())
     }
 
     fn write_indented(&mut self, out: &str) -> io::Result<()> {
-        writeln!(self.write, "{0:1$}{2}", "", self.indent, out)
+        self.write_indentation()?;
+        writeln!(self.write, "{}", out)
     }
 
     pub fn write_table_row<I, C>(&mut self, iterable: I) -> io::Result<()>
@@ -65,7 +69,8 @@ impl<W: Write> RustWrite<W> {
         I: IntoIterator<Item = (i32, C)>,
         C: fmt::Display,
     {
-        if Tls::session().emit_comments {
+        let session = Tls::session();
+        if session.emit_comments {
             for (i, comment) in iterable {
                 try!(self.write_indentation());
                 try!(writeln!(self.write, "{}, {}", i, comment));
@@ -74,7 +79,7 @@ impl<W: Write> RustWrite<W> {
             try!(self.write_indentation());
             let mut first = true;
             for (i, _comment) in iterable {
-                if !first {
+                if !first && session.emit_whitespace {
                     try!(write!(self.write, " "));
                 }
                 try!(write!(self.write, "{},", i));

lalrpop/src/session.rs

@@ -41,6 +41,9 @@ pub struct Session {
     /// forth.
     pub emit_comments: bool,
 
+    /// Emit whitespace in the generated code to improve readability.
+    pub emit_whitespace: bool,
+
     /// Emit report file about generated code
     pub emit_report: bool,
 
@@ -92,6 +95,7 @@ impl Session {
             out_dir: None,
             force_build: false,
             emit_comments: false,
+            emit_whitespace: true,
             emit_report: false,
             color_config: ColorConfig::default(),
             max_errors: 1,
@@ -117,6 +121,7 @@ impl Session {
             out_dir: None,
             force_build: false,
             emit_comments: false,
+            emit_whitespace: true,
             emit_report: false,
             color_config: ColorConfig::IfTty,
             max_errors: 1,

snap.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-cargo run -p lalrpop -- --force --out-dir . lalrpop/src/parser/lrgrammar.lalrpop
+cargo run -p lalrpop -- --force --no-whitespace --out-dir . lalrpop/src/parser/lrgrammar.lalrpop