Grammar: support function-call syntax in outputs

This change adds syntax support for function call outputs. For example:

... | syslog(evt, WARN)

Regular outputs are still allowed and parsed in the same way.

userspace/digwatch/lua/compiler.lua

@@ -167,6 +167,10 @@ local function outputformat (format)
    return {type = "OutputFormat", value = format}
 end
 
+local function functioncall (name, args)
+   return {type = "FunctionCall", name = name, arguments = args}
+end
+
 local function rule(filter, output)
    if not output then
       output = outputformat("")
@@ -182,7 +186,7 @@ local G = {
   -- Grammar
    Comment = P"#" * P(1)^0;
 
-   Rule = V"Filter" / filter * ((V"Skip" * V"Pipe" * V"Skip" * (P(1)^0 / outputformat) )^-1 );
+   Rule = V"Filter" / filter * ((V"Skip" * V"Pipe" * V"Skip" * V"Output")^-1 );
 
    Filter = V"OrExpression";
   OrExpression =
@@ -212,6 +216,9 @@ local G = {
 
   MacroDef = (C(V"Macro") * V"Skip" * V"Colon" * (V"Filter"));
 
+  FuncArgs = symb("(") * list(V"Value", symb(",")) * symb(")");
+  Output = ((V"Name" * V"FuncArgs") / functioncall) + P(1)^0 / outputformat;
+
   -- Terminals
   Value = terminal "Number" + terminal "String" + terminal "BareString";
 
@@ -448,8 +455,17 @@ function print_ast(ast, level)
    if t == "Rule" then
       print_ast(ast.filter, level)
       if (ast.output) then
-	 print(prefix.."| "..ast.output.value)
+	 print(prefix.."| ")
+	 print_ast(ast.output)
       end
+   elseif t == "OutputFormat" then
+      print(ast.value)
+
+   elseif t == "FunctionCall" then
+      print(ast.name .. "(" )
+      print_ast(ast.arguments)
+      print(")")
+
    elseif t == "Filter" then
       print_ast(ast.value, level)
 
@@ -463,7 +479,6 @@ function print_ast(ast, level)
       print_ast(ast.argument, level)
 
    elseif t == "List" then
-      print(prefix.. "List: ")
       for i, v in ipairs(ast.elements) do
          print_ast(v, level)
       end

userspace/digwatch/lua/smoke.sh

@@ -57,8 +57,6 @@ good "evt.dir=> and fd.name=*.log"
 good "evt.dir=> and fd.name=/var/log/httpd.log"
 good "a.g in (1, 'a', b.c)"
 good "a.b = a.a"
-good "a.b = a.a |"
-good "a.b = a.a | %evt.type %fd.num blabla"
 
 good "evt.arg[0] contains /bin"
 bad "evt.arg[a] contains /bin"
@@ -67,9 +65,9 @@ bad "evt.arg[] contains /bin"
 bad "a.g in ()"
 bad "a.b = b = 1"
 bad "(a.b = 1"
-bad " | %a.b"
-# Macros
 
+
+# Macros
 good "a: a.b exists"
 good "a: b and c"
 good "a: b"
@@ -77,9 +75,19 @@ good "a : b"
 good "a : evt.dir=>"
 good "inbound: (syscall.type=listen and evt.dir='>') or (syscall.type=accept and evt.dir='<')"
 bad "a:"
-bad "a : b | bla"
 bad "b and d"
 
+# Outputs
+good "a.b = a.a |"
+good "a.b = a.a | %evt.type %fd.num blabla"
+good "a.b = a.a | blabla (%evt.type %fd.num)"
+good "a.b = a.a | f(evt)"
+good "a.b = a.a | f()"
+bad "a.b = a.a | f() evt"
+
+bad "a : b | bla"
+bad " | %a.b"
+
 
 echo
 echo "All tests passed."