cmd/format: be consistent with whitespace in lists

Leading whitespace is not strictly enforced, but is incorrectly present
when the formatting of a list is fixed. The behaviour can be made
consistent by requesting no blanks at the start of a list.

	```diff
	-[ 1]
	-[ for x in y {}]
	+[1]
	+ [for x in y {}]
	```

Fixes #1023

Change-Id: I8a57461d99cf6fd67105ab01283906e8ee60fac8
Signed-off-by: Thomas Way <thomas@6f.io>
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1171302
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>

cmd/cue/cmd/eval.go

@@ -42,7 +42,7 @@ configuration file, instead of the entire configuration file itself.
 Examples:
 
   $ cat <<EOF > foo.cue
-  a: [ "a", "b", "c" ]
+  a: ["a", "b", "c"]
   EOF
 
   $ cue eval foo.cue -e a[0] -e a[2]

cmd/cue/cmd/root.go

@@ -140,7 +140,7 @@ Commands are defined in CUE as follows:
 	command: deploy: {
 		exec.Run
 		cmd:   "kubectl"
-		args:  [ "-f", "deploy" ]
+		args:  ["-f", "deploy"]
 		in:    json.Encode(userValue) // encode the emitted configuration.
 	}
 

cmd/cue/cmd/testdata/script/cmd_cycle.txtar

@@ -99,7 +99,7 @@ for _, input in inputs {
 }
 
 command: print: cli.Print & {
-	text: strings.Join([ for key, val in outputs { "key=\(key) val=\(val)" } ], "\n")
+	text: strings.Join([for key, val in outputs { "key=\(key) val=\(val)" }], "\n")
 }
 
 -- stdout2397.golden --

cmd/cue/cmd/testdata/script/cmd_func.txtar

@@ -8,7 +8,7 @@ import "encoding/json"
 
 x: y: 2
 
-objects: [ for v in [ json.Marshal(x) ] {v} ]
+objects: [for v in [json.Marshal(x)] {v}]
 
 -- k_tool.cue --
 package kube

cmd/cue/cmd/testdata/script/cmd_issue2060.txtar

@@ -118,9 +118,9 @@ buildSource: {
 			Bindings: [
 				for _, strokeDef in strokeDefs {
 					let bindingMap = strokeDef.Bindings["\(PlatformName)"]
-					let bindingIds = [ for k, v in bindingMap {name: k, idx: v}]
+					let bindingIds = [for k, v in bindingMap {name: k, idx: v}]
 					let bindingIdsSorted = list.Sort(bindingIds, {x: {}, y: {}, less: x.idx < y.idx})
-					let bindingKeys = [ for _, kv in bindingIdsSorted {kv.name}]
+					let bindingKeys = [for _, kv in bindingIdsSorted {kv.name}]
 					let bindingText = strings.Join(bindingKeys, "+")
 					"DefText":  "\(strokeDef.DefText)"
 					"BindText": bindingText

cmd/cue/cmd/testdata/script/eval_mixedfiletypes.txtar

@@ -40,7 +40,7 @@ checks: {
 	}
 
 	hasManager: {
-		ok: len([ for m in team if list.Contains(m, "EM") {m}]) >= 1
+		ok: len([for m in team if list.Contains(m, "EM") {m}]) >= 1
 	}
 }
 -- y.cue --

cmd/cue/cmd/testdata/script/help.txtar

@@ -19,7 +19,7 @@ Commands are defined in CUE as follows:
 	command: deploy: {
 		exec.Run
 		cmd:   "kubectl"
-		args:  [ "-f", "deploy" ]
+		args:  ["-f", "deploy"]
 		in:    json.Encode(userValue) // encode the emitted configuration.
 	}
 

cmd/cue/cmd/testdata/script/issue473.txtar

@@ -10,7 +10,7 @@ package x
 
         Steps: [string]: #Step
 
-        #TerminalName: or([ for k, _ in Terminals {k}])
+        #TerminalName: or([for k, _ in Terminals {k}])
 
         #Step: {
                 Terminal: #TerminalName
@@ -33,4 +33,4 @@ g: #Guide & {
                         Cmd:      "ls"
                 }
         }
-}
+}

cmd/cue/cmd/testdata/script/load_pkg.txtar

@@ -61,7 +61,7 @@ foo: int
 bar: 3
 -- sort/print.cue --
 files: {}
-flat: [ for k, _ in files {k} ]
+flat: [for k, _ in files {k}]
 -- sort/root_1.cue --
 files: root_1: 0
 -- sort/root_2/child_1.cue --

cmd/cue/cmd/testdata/script/merge_interaction.txtar

@@ -16,7 +16,7 @@ import (
 	"tool/cli"
 )
 
-objects: [ for x in map {x}]
+objects: [for x in map {x}]
 
 command: dump: {
 	cli.Print & {

cue/format/node.go

@@ -659,7 +659,7 @@ func (f *formatter) exprRaw(expr ast.Expr, prec1, depth int) {
 		f.print(ws, x.Rbrace, token.RBRACE)
 
 	case *ast.ListLit:
-		f.print(x.Lbrack, token.LBRACK, indent)
+		f.print(x.Lbrack, token.LBRACK, noblank, indent)
 		f.walkListElems(x.Elts)
 		f.print(trailcomma, noblank)
 		f.visitComments(f.current.pos)

cue/format/testdata/expressions.golden

@@ -144,10 +144,10 @@ import "list"
 	e: [...int]
 	e: [...int]
 	e: [...int | float]
-	e: [ for x in someObject if x > 9 {
+	e: [for x in someObject if x > 9 {
 		x
 	}]
-	e: [ for x in someObject if x > 9 {x}]
+	e: [for x in someObject if x > 9 {x}]
 	e: [
 		for x in someObject
 		if x > 9 {x}]
@@ -253,4 +253,20 @@ import "list"
 
 		2,
 	])
+
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [1, 2, 3]
+	m: [if true {1}, 2, 3]
+	n: [1]
+	o: [{}]
+	o: [{}]
+	o: [{}]
+	o: [{}]
 }

cue/format/testdata/expressions.input

@@ -142,10 +142,10 @@ import "list"
     e: [...int]
     e: [...int,]
     e: [...int | float]
-    e: [ for x in someObject if x > 9 {
+    e: [for x in someObject if x > 9 {
         x
     }]
-    e: [ for x in someObject if x > 9 {x}]
+    e: [for x in someObject if x > 9 {x}]
     e: [
     for x in someObject
     if x > 9 {x}]
@@ -250,4 +250,20 @@ import "list"
 
         2,
     ])
+
+    m: [1, 2, 3]
+    m: [1, 2, 3,]
+    m: [ 1, 2, 3, ]
+    m: [    1, 2, 3,]
+    m: [     1, 2, 3,]
+    m: [ 1, 2, 3]
+    m: [ 1, 2, 3,]
+    m: [ 1, 2, 3, ]
+    m: [ 1, 2, 3 ]
+    m: [ if true { 1 }, 2, 3]
+    n: [ 1]
+    o: [{}]
+    o: [ {}]
+    o: [{} ]
+    o: [ {} ]
 }

cue/parser/parser_test.go

@@ -300,7 +300,7 @@ func TestParse(t *testing.T) {
 		"list types",
 		`{
 			a: 4*[int]
-			b: <=5*[ {a: 5} ]
+			b: <=5*[{a: 5}]
 			c1: [...int]
 			c2: [...]
 			c3: [1, 2, ...int,]
@@ -310,7 +310,7 @@ func TestParse(t *testing.T) {
 		"list comprehensions",
 		`{
 				y: [1,2,3]
-				b: [ for x in y if x == 1 { x } ],
+				b: [for x in y if x == 1 { x }],
 			}`,
 		`{y: [1, 2, 3], b: [for x in y if x==1 {x}]}`,
 	}, {

cue/testdata/benchmarks/issue2176.txtar

@@ -37,7 +37,7 @@ import (
 					}
 				}
 			}
-			[ for i, _ in unique_combinations {i}][0]
+			[for i, _ in unique_combinations {i}][0]
 		}
 	}
 }

cue/testdata/builtins/incomplete.txtar

@@ -14,7 +14,7 @@ list1: {
 
 	// This evaluates to a list with an incomplete element.
 	Top: [
-		[ for _, F in _Sub {F}],
+		[for _, F in _Sub {F}],
 	]
 
 	_Sub: a.b

cue/testdata/compile/labels.txtar

@@ -22,7 +22,7 @@ ok9: [name=dis2]:                   string
 ok10: [{foo:                        "bar"}]: string // disallowed in evaluator
 ok11: [list.FlattenN([string], 1)]: string   // disallowed in evaluator
 
-bad1: [ for x in [1, 2, 3] {x}]: string
+bad1: [for x in [1, 2, 3] {x}]: string
 
 saneReferencesInComprehensions: {
 	for _ in [1] {
@@ -31,7 +31,7 @@ saneReferencesInComprehensions: {
 }
 -- out/compile --
 bad1: comprehension values not allowed in this position:
-    ./in.cue:24:9
+    ./in.cue:24:8
 --- in.cue
 {
   dis1: ("dev"|"prd")
@@ -91,4 +91,4 @@ bad1: comprehension values not allowed in this position:
 }
 -- out/eval --
 bad1: comprehension values not allowed in this position:
-    ./in.cue:24:9
+    ./in.cue:24:8

cue/testdata/comprehensions/015_list_comprehension.txtar

@@ -3,15 +3,15 @@
 #name: list comprehension
 #evalFull
 -- in.cue --
-a: [ for k, v in b if k < "d" if v > b.a {k}]
+a: [for k, v in b if k < "d" if v > b.a {k}]
 b: {
 	a: 1
 	b: 2
 	c: 3
 	d: 4
 }
-c: [ for _, x in b for _, y in b if x < y {x}]
-d: [ for x, _ in a {x}]
+c: [for _, x in b for _, y in b if x < y {x}]
+d: [for x, _ in a {x}]
 -- out/def --
 a: ["b", "c"]
 b: {

cue/testdata/comprehensions/checkdefined.txtar

@@ -17,31 +17,31 @@ okc1: { if xc.undefined != _|_ {a: 1} }
 oko1: { if xo.undefined != _|_ {a: 1} }
 
 okc2: {
-	if ({} & {s: [ for y in xc.undefined {}]}) != _|_ {a: 1}
+	if ({} & {s: [for y in xc.undefined {}]}) != _|_ {a: 1}
 }
 
 oko2: {
-	if ({} & {s: [ for y in xo.undefined {}]}) != _|_ {a: 1}
+	if ({} & {s: [for y in xo.undefined {}]}) != _|_ {a: 1}
 }
 
 okc3: {
-	if ({s: [ for y in xc.undefined {}]}) != _|_ {a: 1}
+	if ({s: [for y in xc.undefined {}]}) != _|_ {a: 1}
 }
 
 oko3: {
-	if ({s: [ for y in xo.undefined {}]}) != _|_ {a: 1}
+	if ({s: [for y in xo.undefined {}]}) != _|_ {a: 1}
 }
 
 issue1969: okc: {
 	let X = xc.undefined
-	let Y = {} & {s: [ for y in list.Range(0, X, 1) {}]}
+	let Y = {} & {s: [for y in list.Range(0, X, 1) {}]}
 
 	if Y != _|_ {Y}
 }
 
 issue1969: oko: {
 	let X = xo.undefined
-	let Y = {} & {s: [ for y in list.Range(0, X, 1) {}]}
+	let Y = {} & {s: [for y in list.Range(0, X, 1) {}]}
 
 	if Y != _|_ {Y}
 }

cue/testdata/comprehensions/incomplete.txtar

@@ -3,7 +3,7 @@ cond: bool
 src: {}
 top: _
 a: [ if cond {}]
-b: [ for x in src.foo {}]
+b: [for x in src.foo {}]
 c: {for x in top {}}
 -- out/eval/stats --
 Leaks:  0
@@ -27,7 +27,7 @@ Disjuncts:    7
   }
   b: (_|_){
     // [incomplete] b: undefined field: foo:
-    //     ./in.cue:5:19
+    //     ./in.cue:5:18
   }
   c: (_|_){
     // [incomplete] c: cannot range over top (incomplete type _):

cue/testdata/comprehensions/lists.txtar

@@ -1,7 +1,7 @@
 -- in.cue --
 a: [{a: 1}, {b: 2 & 3}]
 
-b: [ for x in a {x}]
+b: [for x in a {x}]
 -- out/eval/stats --
 Leaks:  0
 Freed:  7

cue/testdata/cycle/chain.txtar

@@ -100,7 +100,7 @@ issue2052: t1: {
 			out: {
 				if (#in & #basic) != _|_ {1}
 				if (#in & #basic) == _|_ {
-					list.Max([ for k, v in #in {(#next & {#in: v}).out}]) + 1
+					list.Max([for k, v in #in {(#next & {#in: v}).out}]) + 1
 				}
 			}
 		}
@@ -139,7 +139,7 @@ issue2052: t2: {
 			out: {
 				if (#in & #basic) != _|_ {1}
 				if (#in & #basic) == _|_ {
-					list.Max([ for k, v in #in {(#next & {#in: v}).out}]) + 1
+					list.Max([for k, v in #in {(#next & {#in: v}).out}]) + 1
 				}
 			}
 		}
@@ -188,7 +188,7 @@ issue2052: full: {
 				// if we are not a basic type, then we are 1 + the max of children
 				if (#in & #basic) == _|_ {
 					// this is our "recursion" for each child
-					let depths = [ for k, v in #in {(#next & {#in: v}).out}]
+					let depths = [for k, v in #in {(#next & {#in: v}).out}]
 					list.Max(depths) + 1
 				}
 			}