Implement ${A-hogehoge} and ${A+hogehoge} temporary

Author: ryuichiueda

src/core/builtins/unset.rs

@@ -19,6 +19,10 @@ fn unset_function(core: &mut ShellCore, name: &str) -> i32 {
 }
 
 pub fn unset(core: &mut ShellCore, args: &mut Vec<String>) -> i32 {
+    if args.len() < 2 {
+        return 0;
+    }
+
     match args[1].as_ref() {
         "-f" => {
             if args.len() > 2 {

src/elements/subword/braced_param.rs

@@ -50,7 +50,6 @@ impl Subword for BracedParam {
             return false;
         }
         if self.unknown.len() > 0 
-        && ! self.unknown.starts_with("-")
         && ! self.unknown.starts_with(",") {
             eprintln!("sush: {}: bad substitution", &self.text);
             return false;
@@ -72,7 +71,13 @@ impl Subword for BracedParam {
             };
         }
 
-        match self.default_symbol.as_ref() {
+        match self.default_symbol.as_deref() {
+            Some("-") => {
+                self.default_value = None;
+                self.default_symbol = None;
+                return true;
+            },
+            Some("+") => return true,
             Some(s) => if s == ":+" || self.text == "" {
                 return self.replace_to_default(core);
             },

src/elements/subword/error

@@ -1,2 +1,4 @@
 ../../../test/test_others.bash
 ../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash

src/feeder/scanner.rs

@@ -276,7 +276,7 @@ impl Feeder {
     }
 
     pub fn scanner_parameter_default_symbol(&mut self) -> usize {
-        self.scanner_one_of(&[":-", ":=", ":?", ":+"])
+        self.scanner_one_of(&[":-", ":=", ":?", ":+", "-", "+"])
     }
 
     pub fn scanner_test_check_option(&mut self, core: &mut ShellCore) -> usize {

test/error

@@ -0,0 +1,8 @@
+./test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash

test/ok

@@ -2,5 +2,11 @@
 ./test_builtins.bash
 ./test_brace.bash
 ./test_compound.bash
-./test_others.bash
 ./test_job.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash
+../../../test/test_others.bash

test/test_others.bash

@@ -79,6 +79,12 @@ ok" ] || err $LINENO
 res=$($com <<< 'A=aaa ; echo ${A- - - - -}' )
 [ "$res" = "aaa" ] || err $LINENO
 
+res=$($com <<< 'A=aaa ; echo ${A+- - - - bbb}' )
+[ "$res" = "- - - - bbb" ] || err $LINENO
+
+res=$($com <<< 'A= ; echo ${A+- - - - bbb}' )
+[ "$res" = "- - - - bbb" ] || err $LINENO
+
 res=$($com <<< 'echo ${A:-   abc}' )
 [ "$res" = "abc" ] || err $LINENO