However, the order of those events compared to the evaluation
and indexing of <code>x</code> and the evaluation
of <code>y</code> is not specified.
</p>

<pre>
a := 1
f := func() int { a++; return a }
x := []int{a, f()}            // x may be [1, 2] or [2, 2]: evaluation order between a and f() is not specified
m := map[int]int{a: 1, a: 2}  // m may be {2: 1} or {2: 2}: evaluation order between the two map assignments is not specified

	// Junk at EOF.
	{"3 x", 3, false},
	// Big number
	{"4611686018427387904", 4611686018427387904, true},
}

func TestExpr(t *testing.T) {
	p := NewParser(nil, nil, nil) // Expression evaluation uses none of these fields of the parser.
	for i, test := range exprTests {
		p.start(lex.Tokenize(test.input))
		result := int64(p.expr())
		if result != test.output {

precision, and vice versa.
</p>


<h3 id="Order_of_evaluation">Order of evaluation</h3>

<p>
At package level, <a href="#Package_initialization">initialization dependencies</a>
determine the evaluation order of individual initialization expressions in
<a href="#Variable_declarations">variable declarations</a>.
Otherwise, when evaluating the <a href="#Operands">operands</a> of an
expression, assignment, or

// compared to the old yacc/C implementations. Neither has
// much practical consequence because the expressions we
// see in assembly code are simple, but for the record:
//
// 1) Evaluation uses uint64; the old one used int64.
// 2) Precedence uses Go rules not C rules.

// expr = term | term ('+' | '-' | '|' | '^') term.
func (p *Parser) expr() uint64 {
	value := p.term()
	for {

</pre>

<h3 id="constants">Constants</h3>

<p>
Although the assembler takes its guidance from the Plan 9 assemblers,
it is a distinct program, so there are some differences.
One is in constant evaluation.
Constant expressions in the assembler are parsed using Go's operator
precedence, not the C-like precedence of the original.
Thus <code>3&amp;1&lt;&lt;2</code> is 4, not 0—it parses as <code>(3&amp;1)&lt;&lt;2</code>

description: Changes to the language
labels: ["Proposal", "v2", "LanguageChange"]
title: "proposal: Go 2: proposal title"


body:
  - type: markdown
    attributes:
      value: |
       ## Our process for evaluating language changes can be found [here](https://go.googlesource.com/proposal/+/refs/heads/master#language-changes)

  - type: dropdown
    id: author-go-experience
    attributes:
      label: "Go Programming Experience"

defined as the partial order requirements set out by the <a href="/ref/spec">Go language specification</a>
for Go's control flow constructs as well as the <a href="/ref/spec#Order_of_evaluation">order of evaluation for expressions</a>.
</p>

<p>
A Go <i>program execution</i> is modeled as a set of goroutine executions,