slightly cleaner parsing

2 files changed, 86 insertions, 80 deletions

diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index 1e88337..f418600 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -730,14 +730,11 @@ impl Parse for ExpString {
                     }
                 }
 
-                let x = b.peek();
+                let x = b.adv();
 
                 if x == b'\\' {
-                    b.adv();
                     add_char(p, parse_escape_code(b)?);
                 } else if x == b'$' && !delim.is_strict() {
-                    b.adv();
-
                     if !b.has() {
                         add_char(p, b'$');
                         continue;
@@ -745,98 +742,99 @@ impl Parse for ExpString {
 
                     let x = b.peek();
 
-                    if x == b'?' || x == b'!' {
-                        b.adv();
-                        p.push(StringPart::Var(Var::new(VarName { name: vec![x] })))
-                    } else if is_var_begin(x) {
+                    if is_var_begin(x) {
                         let v = VarName::parse(b)?;
                         p.push(StringPart::Var(Var::new(v)));
-                    } else if x == b'{' {
-                        b.adv();
-                        let v = VarName::parse(b)?;
-                        let mut default = None;
+                        continue;
+                    }
+
+                    b.adv();
+
+                    match x {
+                        b'?' | b'!' => p.push(StringPart::Var(Var::new(VarName { name: vec![x] }))),
+                        b'{' => {
+                            let v = VarName::parse(b)?;
+                            let mut default = None;
 
-                        if !b.has() {
-                            if !b.is_completion() {
-                                return Err(ParseError::Eof);
-                            }
-                        } else if b.peek() == b':' {
-                            b.adv();
                             if !b.has() {
-                                return Err(ParseError::Eof);
-                            }
-                            if b.peek() == b'-' {
+                                if !b.is_completion() {
+                                    return Err(ParseError::Eof);
+                                }
+                            } else if b.peek() == b':' {
                                 b.adv();
-                                default = Some(ExpString::parse(b)?);
-                            } else {
-                                todo!(": in var expansion")
+                                if !b.has() {
+                                    return Err(ParseError::Eof);
+                                }
+                                if b.peek() == b'-' {
+                                    b.adv();
+                                    default = Some(ExpString::parse(b)?);
+                                } else {
+                                    todo!(": in var expansion")
+                                }
                             }
-                        }
 
-                        if !b.has() {
-                            if !b.is_completion() {
-                                return Err(ParseError::Eof);
+                            if !b.has() {
+                                if !b.is_completion() {
+                                    return Err(ParseError::Eof);
+                                }
+                            } else if b.peek() != b'}' {
+                                return Err(ParseError::Expected('}'));
                             }
-                        } else if b.peek() != b'}' {
-                            return Err(ParseError::Expected('}'));
-                        }
 
-                        let already_complete = b.has();
+                            let already_complete = b.has();
 
-                        if already_complete {
-                            b.adv();
-                        }
+                            if already_complete {
+                                b.adv();
+                            }
 
-                        p.push(StringPart::Var(Var {
-                            name: v,
-                            default,
-                            already_complete,
-                        }));
-                    } else if x == b'(' {
-                        b.adv();
-                        let cmd = Ast::parse(b)?;
-                        b.spaces();
-
-                        if b.is_empty() && !b.is_completion() {
-                            return Err(ParseError::Expected(')'));
+                            p.push(StringPart::Var(Var {
+                                name: v,
+                                default,
+                                already_complete,
+                            }));
                         }
+                        b'(' => {
+                            let cmd = Ast::parse(b)?;
+                            b.spaces();
 
-                        if b.has() && b.peek() == b')' {
-                            b.adv();
-                            p.push(StringPart::Cmd(CmdInterp {
-                                cmd,
-                                already_complete: true,
-                            }));
-                        } else if b.is_completion() {
-                            p.push(StringPart::Cmd(CmdInterp {
-                                cmd,
-                                already_complete: false,
-                            }))
-                        } else {
-                            return Err(ParseError::Expected(')'));
+                            if b.is_empty() && !b.is_completion() {
+                                return Err(ParseError::Expected(')'));
+                            }
+
+                            if b.has() && b.peek() == b')' {
+                                b.adv();
+                                p.push(StringPart::Cmd(CmdInterp {
+                                    cmd,
+                                    already_complete: true,
+                                }));
+                            } else if b.is_completion() {
+                                p.push(StringPart::Cmd(CmdInterp {
+                                    cmd,
+                                    already_complete: false,
+                                }))
+                            } else {
+                                return Err(ParseError::Expected(')'));
+                            }
+                        }
+                        x => {
+                            add_char(p, b'$');
+                            add_char(p, x);
                         }
-                    } else {
-                        // doesn't seem to be a variable or expansion, just add $ back into the string
-                        add_char(p, b'$');
                     }
+                } else if delim.is_none()
+                    && x == b'~'
+                    && p.is_empty()
+                    && (!b.has() || b.peek().is_ascii_whitespace() || b.peek() == b'/')
+                {
+                    p.push(StringPart::Var(Var {
+                        name: VarName {
+                            name: b"HOME".to_vec(),
+                        },
+                        default: None,
+                        already_complete: true,
+                    }));
                 } else {
-                    b.adv();
-
-                    if delim.is_none()
-                        && x == b'~'
-                        && p.is_empty()
-                        && (!b.has() || b.peek().is_ascii_whitespace() || b.peek() == b'/')
-                    {
-                        p.push(StringPart::Var(Var {
-                            name: VarName {
-                                name: b"HOME".to_vec(),
-                            },
-                            default: None,
-                            already_complete: true,
-                        }));
-                    } else {
-                        add_char(p, x);
-                    }
+                    add_char(p, x);
                 }
             }
         }
diff --git a/src/parse/test.rs b/src/parse/test.rs
index 3513c3f..3058730 100644
--- a/src/parse/test.rs
+++ b/src/parse/test.rs
@@ -321,3 +321,11 @@ fn exit_code_2() {
         pipes([cmd([estr(b"echo"), str([var(b"?")])])])
     )
 }
+
+#[test]
+fn dollar_non_var() {
+    parse_test!(
+        parse(b"echo $_"),
+        pipes([cmd([estr(b"echo"), estr(b"$_")]),])
+    )
+}