Deprecate = in assignments, aliases, and exports in favor of :=

GRAMMAR.md

@@ -49,23 +49,23 @@ item          : recipe
 eol           : NEWLINE
               | COMMENT NEWLINE
 
-assignment    : NAME '=' expression eol
+alias         : 'alias' NAME ':=' NAME
 
-alias         : 'alias' NAME '=' NAME
+assignment    : NAME ':=' expression eol
 
 export        : 'export' assignment
 
 expression    : value '+' expression
               | value
 
-value         : NAME '(' arguments? ')'
+value         : NAME '(' sequence? ')'
               | STRING
               | RAW_STRING
               | BACKTICK
               | NAME
               | '(' expression ')'
 
-arguments     : expression ',' arguments
+sequence      : expression ',' sequence
               | expression ','?
 
 recipe        : '@'? NAME parameter* ('+' parameter)? ':' dependencies? body?

README.adoc

@@ -210,7 +210,7 @@ build test deploy lint
 Aliases allow recipes to be invoked with alternative names:
 
 ```make
-alias b = build
+alias b := build
 
 build:
   echo 'Building!'
@@ -249,9 +249,9 @@ Available recipes:
 Variables, strings, concatenation, and substitution using `{{...}}` are supported:
 
 ```make
-version = "0.2.7"
-tardir  = "awesomesauce-" + version
-tarball = tardir + ".tar.gz"
+version := "0.2.7"
+tardir  := "awesomesauce-" + version
+tarball := tardir + ".tar.gz"
 
 publish:
     rm -f {{tarball}}
@@ -285,29 +285,29 @@ braces:
 Double-quoted strings support escape sequences:
 
 ```make
-string-with-tab             = "\t"
-string-with-newline         = "\n"
-string-with-carriage-return = "\r"
-string-with-double-quote    = "\""
-string-with-slash           = "\\"
+string-with-tab             := "\t"
+string-with-newline         := "\n"
+string-with-carriage-return := "\r"
+string-with-double-quote    := "\""
+string-with-slash           := "\\"
 ```
 
 ```sh
 $ just --evaluate
-"tring-with-carriage-return = "
-string-with-double-quote    = """
-string-with-newline         = "
+"tring-with-carriage-return := "
+string-with-double-quote    := """
+string-with-newline         := "
 "
-string-with-slash           = "\"
-string-with-tab             = "     "
+string-with-slash           := "\"
+string-with-tab             := "     "
 ```
 
 Single-quoted strings do not recognize escape sequences and may contain line breaks:
 
 ```make
-escapes = '\t\n\r\"\\'
+escapes := '\t\n\r\"\\'
 
-line-breaks = 'hello
+line-breaks := 'hello
 this
 is
   a
@@ -318,9 +318,9 @@ string!
 
 ```sh
 $ just --evaluate
-escapes = "\t\n\r\"\\"
+escapes := "\t\n\r\"\\"
 
-line-breaks = "hello
+line-breaks := "hello
 this
 is
   a
@@ -410,7 +410,7 @@ Starting server with database localhost:6379 on port 1337...
 Backticks can be used to store the result of commands:
 
 ```make
-localhost = `dumpinterfaces | cut -d: -f2 | sed 's/\/.*//' | sed 's/ //g'`
+localhost := `dumpinterfaces | cut -d: -f2 | sed 's/\/.*//' | sed 's/ //g'`
 
 serve:
     ./serve {{localhost}} 8080
@@ -421,7 +421,7 @@ serve:
 Variables can be overridden from the command line.
 
 ```make
-os = "linux"
+os := "linux"
 
 test: build
     ./test --test {{os}}
@@ -457,7 +457,7 @@ $ just --set os bsd
 Assignments prefixed with the `export` keyword will be exported to recipes as environment variables:
 
 ```make
-export RUST_BACKTRACE = "1"
+export RUST_BACKTRACE := "1"
 
 test:
     # will print a stack trace if it crashes
@@ -487,7 +487,7 @@ cd my-awesome-project && make
 Parameters may have default values:
 
 ```make
-default = 'all'
+default := 'all'
 
 test target tests=default:
     @echo 'Testing {{target}}:{{tests}}...'
@@ -513,7 +513,7 @@ Testing server:unit...
 Default values may be arbitrary expressions, but concatenations must be parenthesized:
 
 ```make
-arch = "wasm"
+arch := "wasm"
 
 test triple=(arch + "-unknown-unknown"):
   ./test {{triple}}

justfile

@@ -2,9 +2,9 @@
 # ^ A shebang isn't required, but allows a justfile to be executed
 #   like a script, with `./justfile test`, for example.
 
-bt='0'
+bt = '0'
 
-export RUST_BACKTRACE=bt
+export RUST_BACKTRACE = bt
 
 alias t = test
 

src/alias.rs

@@ -10,6 +10,6 @@ pub struct Alias<'a> {
 
 impl<'a> Display for Alias<'a> {
   fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-    write!(f, "alias {} = {}", self.name, self.target)
+    write!(f, "alias {} := {}", self.name, self.target)
   }
 }

src/color.rs

@@ -76,6 +76,10 @@ impl Color {
     self.restyle(Style::new().fg(Red).bold())
   }
 
+  pub fn warning(self) -> Color {
+    self.restyle(Style::new().fg(Yellow).bold())
+  }
+
   pub fn banner(self) -> Color {
     self.restyle(Style::new().fg(Cyan).bold())
   }

src/justfile.rs

@@ -6,6 +6,7 @@ pub struct Justfile<'a> {
   pub assignments: BTreeMap<&'a str, Expression<'a>>,
   pub exports: BTreeSet<&'a str>,
   pub aliases: BTreeMap<&'a str, Alias<'a>>,
+  pub deprecated_equals: bool,
 }
 
 impl<'a> Justfile<'a> where {
@@ -80,7 +81,7 @@ impl<'a> Justfile<'a> where {
       }
 
       for (name, value) in scope {
-        println!("{0:1$} = \"{2}\"", name, width, value);
+        println!("{0:1$} := \"{2}\"", name, width, value);
       }
       return Ok(());
     }
@@ -175,7 +176,7 @@ impl<'a> Display for Justfile<'a> {
       if self.exports.contains(name) {
         write!(f, "export ")?;
       }
-      write!(f, "{} = {}", name, expression)?;
+      write!(f, "{} := {}", name, expression)?;
       items -= 1;
       if items != 0 {
         write!(f, "\n\n")?;

src/lexer.rs

@@ -323,7 +323,7 @@ impl<'a> Lexer<'a> {
       '@' => self.lex_single(At),
       '=' => self.lex_single(Equals),
       ',' => self.lex_single(Comma),
-      ':' => self.lex_single(Colon),
+      ':' => self.lex_colon(),
       '(' => self.lex_single(ParenL),
       ')' => self.lex_single(ParenR),
       '{' => self.lex_brace_l(),
@@ -442,6 +442,20 @@ impl<'a> Lexer<'a> {
     Ok(())
   }
 
+  /// Lex a token starting with ':'
+  fn lex_colon(&mut self) -> CompilationResult<'a, ()> {
+    self.advance()?;
+
+    if let Some('=') = self.next {
+      self.advance()?;
+      self.token(ColonEquals);
+    } else {
+      self.token(Colon);
+    }
+
+    Ok(())
+  }
+
   /// Lex a token starting with '{'
   fn lex_brace_l(&mut self) -> CompilationResult<'a, ()> {
     if !self.rest_starts_with("{{") {