internal/core/adt: change semantics of unary_op(basictype)

This seems wrong. New evaluator handles this correctly based on
semantics of old evaluator, which means it ends up silently ignoring
incomplete errors. The old evaluator was inconsistent here.

Rather than mimicing the old behavior, it seems better to adjust
the semantics.

Note that this is a breaking change. It seems odd to write
configurations like this, though, so I don't expect this to be an
issue in practice. If it results in any issues, we can revert
this change and perhaps adjust the new evaluator accordingly.

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: Iab11975e1ea62a15b0a3f9619b9f0b1a84d7a824
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1172014
Reviewed-by: Daniel Martí <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mpvl

cue/testdata/eval/bounds.txtar

@@ -70,7 +70,7 @@ Allocs: 3
 Retain: 1
 
 Unifications: 53
-Conjuncts:    90
+Conjuncts:    110
 Disjuncts:    54
 -- out/eval --
 Errors:
@@ -121,11 +121,26 @@ Result:
     i: (int){ int }
     f: (float){ float }
     b: (bytes){ bytes }
-    basic1: (int){ int }
-    basic2: (number){ number }
-    basic3: (string){ string }
-    basic4: (float){ float }
-    basic5: (bytes){ bytes }
+    basic1: (_|_){
+      // [incomplete] simplifyExpr.basic1: non-concrete value i for bound <:
+      //     ./in.cue:48:12
+    }
+    basic2: (_|_){
+      // [incomplete] simplifyExpr.basic2: non-concrete value n for bound >:
+      //     ./in.cue:49:12
+    }
+    basic3: (_|_){
+      // [incomplete] simplifyExpr.basic3: non-concrete value s for bound >=:
+      //     ./in.cue:50:13
+    }
+    basic4: (_|_){
+      // [incomplete] simplifyExpr.basic4: non-concrete value f for bound <=:
+      //     ./in.cue:51:13
+    }
+    basic5: (_|_){
+      // [incomplete] simplifyExpr.basic5: non-concrete value b for bound <=:
+      //     ./in.cue:52:13
+    }
     bne1: (_|_){
       // [incomplete] simplifyExpr.bne1: non-concrete value s for bound !=:
       //     ./in.cue:55:11

cue/testdata/eval/incomplete.txtar

@@ -3,7 +3,7 @@ s: string
 
 e1:  s + s
 e2:  >"bar" & s // okay
-e3:  >s & "foo" // okay
+e3:  >s & "foo" // not okay
 e3b: >s
 
 e4: >e1 & s
@@ -44,15 +44,15 @@ issue1837: {
 	}
 }
 -- out/eval/stats --
-Leaks:  5
-Freed:  27
-Reused: 21
-Allocs: 11
-Retain: 101
+Leaks:  0
+Freed:  32
+Reused: 26
+Allocs: 6
+Retain: 96
 
 Unifications: 32
-Conjuncts:    159
-Disjuncts:    50
+Conjuncts:    172
+Disjuncts:    45
 -- out/eval --
 (struct){
   s: (string){ string }
@@ -62,8 +62,14 @@ Disjuncts:    50
     //     ./in.cue:1:4
   }
   e2: (string){ >"bar" }
-  e3: (string){ "foo" }
-  e3b: (string){ string }
+  e3: (_|_){
+    // [incomplete] e3: non-concrete value s for bound >:
+    //     ./in.cue:5:7
+  }
+  e3b: (_|_){
+    // [incomplete] e3b: non-concrete value s for bound >:
+    //     ./in.cue:6:7
+  }
   e4: (_|_){
     // [incomplete] e1: non-concrete value string in operand to +:
     //     ./in.cue:3:6
@@ -90,9 +96,8 @@ Disjuncts:    50
   }
   a: (int){ int }
   okay: (_|_){
-    // [incomplete] okay: non-concrete value >10 & int in operand to +:
-    //     ./in.cue:18:7
-    //     ./in.cue:18:8
+    // [incomplete] non-concrete value a for bound <:
+    //     ./in.cue:18:15
   }
   issue1837: (struct){
     p1: (struct){

internal/core/adt/expr.go

@@ -548,7 +548,11 @@ func (x *BoundExpr) evaluate(ctx *OpContext, state vertexStatus) Value {
 	case *BasicType:
 		switch x.Op {
 		case LessEqualOp, LessThanOp, GreaterEqualOp, GreaterThanOp:
-			return y
+			// TODO: this does not seem correct and results in some weird
+			// behavior for bounds.
+			ctx.addErrf(IncompleteError, token.NoPos,
+				"non-concrete value %s for bound %s", x.Expr, x.Op)
+			return nil
 		}
 	}
 	if v.Concreteness() > Concrete {