fun = call.Fun
			n++
		}
	}
	if n != 1 {
		t.Errorf("%s: got %d CallExprs; want 1", src0, n)
		return
	}

	// check recorded types for fun and descendents (may be parenthesized)
	for {
		// the recorded type for the built-in must match the wanted signature
		typ := types[fun].Type
		if typ == nil {
			t.Errorf("%s: no type recorded for %s", src0, ExprString(fun))
			return
		}

	{"field on interface", "{{.foo}}", "<no value>", nil, true},
	{"field on parenthesized interface", "{{(.).foo}}", "<no value>", nil, true},

	// Issue 31810: Parenthesized first element of pipeline with arguments.
	// See also TestIssue31810.
	{"unparenthesized non-function", "{{1 2}}", "", nil, false},
	{"parenthesized non-function", "{{(1) 2}}", "", nil, false},
	{"parenthesized non-function with no args", "{{(1)}}", "1", nil, true}, // This is fine.

	{"field on parenthesized interface", "{{(.).foo}}", "", nil, true}, // NOTE: <no value> in text/template

	// Issue 31810: Parenthesized first element of pipeline with arguments.
	// See also TestIssue31810.
	{"unparenthesized non-function", "{{1 2}}", "", nil, false},
	{"parenthesized non-function", "{{(1) 2}}", "", nil, false},

	"internal/testenv"
	"os"
	"path/filepath"
	"reflect"
	"regexp"
	"runtime"
	"sort"
	"strconv"
	"strings"
	"testing"
)

// Matches lines in genssa output that are marked "isstmt", and the parenthesized plus-prefixed line number is a submatch
var asmLine *regexp.Regexp = regexp.MustCompile(`^\s[vb]\d+\s+\d+\s\(\+(\d+)\)`)

// that identifier. The result is nil if it is the blank identifier,
// and Typ[Invalid] if it is an invalid lhs expression.
func (check *Checker) lhsVar(lhs ast.Expr) Type {
	// Determine if the lhs is a (possibly parenthesized) identifier.
	ident, _ := ast.Unparen(lhs).(*ast.Ident)

	// Don't evaluate lhs if it is the blank identifier.
	if ident != nil && ident.Name == "_" {
		check.recordDef(ident, nil)
		return nil
	}

// be incomplete.
type Info struct {
	// Types maps expressions to their types, and for constant
	// expressions, also their values. Invalid expressions are
	// omitted.
	//
	// For (possibly parenthesized) identifiers denoting built-in
	// functions, the recorded signatures are call-site specific:
	// if the call result is not a constant, the recorded type is
	// an argument-specific signature. Otherwise, the recorded type

and %#g is 6; for %g it is the smallest number of digits necessary to identify
the value uniquely.

For complex numbers, the width and precision apply to the two
components independently and the result is parenthesized, so %f applied
to 1.2+3.4i produces (1.200000+3.400000i).

When formatting a single integer code point or a rune string (type []rune)
with %q, invalid Unicode code points are changed to the Unicode replacement

// be incomplete.
type Info struct {
	// Types maps expressions to their types, and for constant
	// expressions, also their values. Invalid expressions are
	// omitted.
	//
	// For (possibly parenthesized) identifiers denoting built-in
	// functions, the recorded signatures are call-site specific:
	// if the call result is not a constant, the recorded type is
	// an argument-specific signature. Otherwise, the recorded type

	case *ast.ParenExpr:
		// name(x) combines but we are making sure at
		// the call site that x is never parenthesized.
		panic("unexpected parenthesized expression")
	}
	return false
}

// isTypeElem reports whether x is a (possibly parenthesized) type element expression.
// The result is false if x could be a type element OR an ordinary (value) expression.
func isTypeElem(x ast.Expr) bool {

// that identifier. The result is nil if it is the blank identifier,
// and Typ[Invalid] if it is an invalid lhs expression.
func (check *Checker) lhsVar(lhs syntax.Expr) Type {
	// Determine if the lhs is a (possibly parenthesized) identifier.
	ident, _ := syntax.Unparen(lhs).(*syntax.Name)

	// Don't evaluate lhs if it is the blank identifier.
	if ident != nil && ident.Value == "_" {
		check.recordDef(ident, nil)
		return nil
	}