Only allow const/literal senders inside chained connections

e2e/array_inport_holes/main/main.neva

@@ -1,10 +1,12 @@
 import { fmt }
 
 def Main(start any) (stop any) {
-	fmt.Printf
-	---
-	:start -> '$1 $2 $3' -> printf:tpl
-	1 -> printf:args[0]
-	3 -> printf:args[2]
-	[printf:sig, printf:err] -> :stop
+        fmt.Printf
+        ---
+        :start -> [
+            '$1 $2 $3' -> printf:tpl,
+            1 -> printf:args[0],
+            3 -> printf:args[2]
+        ]
+        [printf:sig, printf:err] -> :stop
 }

e2e/compiler_error_autonomous_const/e2e_test.go

@@ -0,0 +1,17 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/nevalang/neva/pkg/e2e"
+	"github.com/stretchr/testify/require"
+)
+
+func Test(t *testing.T) {
+	out, err := e2e.RunExpectingError(t, "run", "main")
+	require.Contains(
+		t,
+		out+err,
+		"Constants must be triggered by a signal (e.g. :start -> 42 -> ...)",
+	)
+}

e2e/compiler_error_autonomous_const/main/main.neva

@@ -0,0 +1,11 @@
+import { fmt }
+
+const myConst string = 'Hello, World!'
+
+def Main(start any) (stop any) {
+    p1 fmt.Println
+    p2 fmt.Println
+    ---
+    :start -> p1
+    $myConst -> p2
+}

e2e/compiler_error_autonomous_const/neva.yml

@@ -0,0 +1 @@
+neva: 0.32.0

e2e/compiler_error_unused_outport/main/main.neva

@@ -9,7 +9,7 @@ def Main(start any) (stop any) {
     ---
     :start -> 'Hi, Neva!' -> sub1:data
     sub1:stop-> :stop
-    '1' -> sub2
+    :start -> '1' -> sub2
 }
 
 // Here we are panicking inside the sub-component instead of propagating the error.

e2e/errors_must/main/main.neva

@@ -20,7 +20,9 @@ def Main(start any) (stop any) {
 def Handler(data string) (res any, err error) {
     write_all io.WriteAll?
     ---
-    :data -> write_all:filename
-    'Hello, io.WriteAll!' -> write_all:data
+    :data -> [
+        write_all:filename,
+        'Hello, io.WriteAll!' -> write_all:data
+    ]
     write_all:res -> :res
 }

e2e/hello_world_with_const_sender/main/main.neva

@@ -6,13 +6,15 @@ import {
 const greeting string = 'Hello, World!'
 
 def Main(start any) (stop any) {
-	println fmt.Println<string>
-	lock Lock<string>
-	panic runtime.Panic
-	---
-	:start -> lock:sig
-	$greeting -> lock:data
-	lock:data -> println:data
-	println:res -> :stop
-	println:err -> panic
+        println fmt.Println<string>
+        lock Lock<string>
+        panic runtime.Panic
+        ---
+        :start -> [
+            lock:sig,
+            $greeting -> lock:data
+        ]
+        lock:data -> println:data
+        println:res -> :stop
+        println:err -> panic
 }

e2e/multiply_numbers/main/main.neva

@@ -6,14 +6,16 @@ import {
 const l list<int> = [1, 2, 3]
 
 def Main(start any) (stop any) {
-	fmt.Println<int>
-	Reduce<int, int>{Mul}
-	ListToStream<int>
-	panic runtime.Panic
-	---
-	:start -> $l -> listToStream -> reduce:data
-	1 -> reduce:init
-	reduce -> println:data
-	println:res -> :stop
-	println:err -> panic
+        fmt.Println<int>
+        Reduce<int, int>{Mul}
+        ListToStream<int>
+        panic runtime.Panic
+        ---
+        :start -> [
+            $l -> listToStream -> reduce:data,
+            1 -> reduce:init
+        ]
+        reduce -> println:data
+        println:res -> :stop
+        println:err -> panic
 }

e2e/order_dependend_with_arr_inport/main/main.neva

@@ -7,13 +7,15 @@ const l list<int> = [1, 2, 3]
 
 def Main(start any) (stop any) {
 	fmt.Println<int>
-	Reduce<int, int>{Sub}
-	ListToStream<int>
-	panic runtime.Panic
-	---
-	:start -> $l -> listToStream -> reduce:data
-	0 -> reduce:init
-	reduce -> println:data
-	println:res -> :stop
-	println:err -> panic
+        Reduce<int, int>{Sub}
+        ListToStream<int>
+        panic runtime.Panic
+        ---
+        :start -> [
+            $l -> listToStream -> reduce:data,
+            0 -> reduce:init
+        ]
+        reduce -> println:data
+        println:res -> :stop
+        println:err -> panic
 }

e2e/slow_iteration_with_for/main/main.neva

@@ -18,8 +18,10 @@ def Slow(data int) (res any, err error) {
     time.Delay<int>
     fmt.Println<int>?
     ---
-    :data -> delay:data
-    $time.second -> delay:dur
+    :data -> [
+        delay:data,
+        $time.second -> delay:dur
+    ]
     delay -> println:data
     println:res -> :res
 }

e2e/slow_iteration_with_map/main/main.neva

@@ -22,7 +22,9 @@ def Slow(data int) (res int) {
     delay time.Delay<int>
     dec Dec
     ---
-    :data -> delay:data
-    $time.second -> delay:dur
+    :data -> [
+        delay:data,
+        $time.second -> delay:dur
+    ]
     delay -> dec -> :res
 }

examples/compare_values/main.neva

@@ -13,9 +13,11 @@ def Main(start any) (stop any) {
         2 -> eq:left,
         2 -> eq:right
     ]
-    eq -> ternary:if
-    'They match' -> ternary:then
-    'They do not match' -> ternary:else
+    eq -> [
+        ternary:if,
+        'They match' -> ternary:then,
+        'They do not match' -> ternary:else
+    ]
     ternary -> println
     println:res -> :stop
     println:err -> panic

examples/delayed_echo/main.neva

@@ -16,28 +16,30 @@ def Main(start any) (stop any) {
 	wg sync.WaitGroup
 	panic runtime.Panic
 	---
-	:start -> [
-		'Hello' -> println,
-		1 -> w1,
+        :start -> [
+                'Hello' -> println,
+                1 -> w1,
 		2 -> w2,
 		3 -> w3,
-		4 -> w4,
-		5 -> w5,
-		'World' -> w6
-	]
-	6 -> wg:count
-	[w1:sig, w2:sig, w3:sig, w4:sig, w5:sig, w6:sig, println:res] -> wg:sig
-	wg -> :stop
+                4 -> w4,
+                5 -> w5,
+                'World' -> w6,
+                6 -> wg:count
+        ]
+        [w1:sig, w2:sig, w3:sig, w4:sig, w5:sig, w6:sig, println:res] -> wg:sig
+        wg -> :stop
 	[w1:err, w2:err, w3:err, w4:err, w5:err, w6:err, println:err] -> panic
 }
 
 def Worker(data any) (sig any, err error) {
-	delay time.Delay
-	println fmt.Println?
-	---
-	:data -> delay:data
-	$time.second -> delay:dur
-	delay -> println -> :sig
+        delay time.Delay
+        println fmt.Println?
+        ---
+        :data -> [
+                delay:data,
+                $time.second -> delay:dur
+        ]
+        delay -> println -> :sig
 }
 
 // TODO add unit test

examples/dict/main.neva

@@ -11,8 +11,10 @@ const d dict<string> = {
 def Main(start any) (stop any) {
     Get, fmt.Println, runtime.Panic
     ---
-    :start -> 'name' -> get:key
-    $d -> get:dict
+    :start -> [
+        'name' -> get:key,
+        $d -> get:dict
+    ]
     [get:res, get:err] -> println:data
     println:res -> :stop
     println:err -> panic

examples/filter_list/main.neva

@@ -22,9 +22,7 @@ def IsEven(data int) (res bool) {
     mod Mod
     eq Eq<int>
     ---
-    :data -> mod:left
-    2 -> mod:right
-    mod -> eq:left
-    0 -> eq:right
+    :data -> [mod:left, 2 -> mod:right]
+    mod -> [eq:left, 0 -> eq:right]
     eq -> :res
 }

examples/fizzbuzz/main.neva

@@ -25,16 +25,13 @@ def FizzBuzz(data int) (res any) {
 
     :data -> [mod15, select:then[3]]
 
-    mod15:then -> select:if[0]
-    'FizzBuzz' -> select:then[0]
+    mod15:then -> [select:if[0], 'FizzBuzz' -> select:then[0]]
     mod15:else -> mod3
 
-    mod3:then -> select:if[1]
-    'Fizz' -> select:then[1]
+    mod3:then -> [select:if[1], 'Fizz' -> select:then[1]]
     mod3:else -> mod5
 
-    mod5:then -> select:if[2]
-    'Buzz' -> select:then[2]
+    mod5:then -> [select:if[2], 'Buzz' -> select:then[2]]
     mod5:else -> select:if[3]
 
     select -> :res
@@ -43,26 +40,23 @@ def FizzBuzz(data int) (res any) {
 def Mod15(num int) (then int, else int) {
     h ModHelper
     ---
-    :num -> h:num
-    15 -> h:den
+    :num -> [h:num, 15 -> h:den]
     h:then -> :then
     h:else -> :else
 }
 
 def Mod3(num int) (then int, else int) {
     h ModHelper
     ---
-    :num -> h:num
-    3 -> h:den
+    :num -> [h:num, 3 -> h:den]
     h:then -> :then
     h:else -> :else
 }
 
 def Mod5(num int) (then int, else int) {
     h ModHelper
     ---
-    :num -> h:num
-    5 -> h:den
+    :num -> [h:num, 5 -> h:den]
     h:then -> :then
     h:else -> :else
 }
@@ -73,8 +67,7 @@ def ModHelper(num int, den int) (then int, else int) {
     :num -> [mod:left, cond:data]
     :den -> mod:right
 
-    mod -> eq:left
-    0 -> eq:right
+    mod -> [eq:left, 0 -> eq:right]
     eq -> cond:if
 
     cond:then -> :then

examples/image_png/main.neva

@@ -6,6 +6,7 @@ def NewPixel(x int, y int, c image.RGBA) (pixel image.Pixel) {
 	:x -> pb:x
 	:y -> pb:y
 	:c -> pb:color
+
 	pb -> :pixel
 }
 
@@ -22,9 +23,11 @@ def NewColor(r int, g int, b int, a int) (color image.RGBA) {
 def NewStream(p image.Pixel) (s stream<image.Pixel>) {
 	sb Struct<stream<image.Pixel>>
 	---
-	0 -> sb:idx
-	:p -> sb:data
-	true -> sb:last
+	:p -> [
+		sb:data,
+		0 -> sb:idx,
+		true -> sb:last
+	]
 	sb -> :s
 }
 

examples/match/main.neva

@@ -17,18 +17,16 @@ def Handler(data int) (res any, err error) {
 
     ---
 
-    :data -> match:data
-
-    1 -> match:if[0]
-    'one' -> match:then[0]
-
-    2 -> match:if[1]
-    'two' -> match:then[1]
-
-    3 -> match:if[2]
-    'three' -> match:then[2]
-
-    'four' -> match:else
+    :data -> [
+        match:data,
+        1 -> match:if[0],
+        'one' -> match:then[0],
+        2 -> match:if[1],
+        'two' -> match:then[1],
+        3 -> match:if[2],
+        'three' -> match:then[2],
+        'four' -> match:else
+    ]
 
     match -> println -> :res
 }

examples/reduce_list/main.neva

@@ -11,8 +11,10 @@ def Main(start any) (stop any) {
     println fmt.Println
     panic runtime.Panic
     ---
-    :start -> $lst -> l2s -> reduce:data
-    0 -> reduce:init
+    :start -> [
+        $lst -> l2s -> reduce:data,
+        0 -> reduce:init
+    ]
     reduce -> println:data
     println:res -> :stop
     println:err -> panic