Function ParseExpression

hclsyntax/public.go:44–74

ParseExpression parses the given buffer as a standalone HCL expression, returning it as an instance of Expression.

(src []byte, filename string, start hcl.Pos)

// ParseExpression parses the given buffer as a standalone HCL expression,
// returning it as an instance of Expression.
func ParseExpression(src []byte, filename string, start hcl.Pos) (Expression, hcl.Diagnostics) {
	tokens, diags := LexExpression(src, filename, start)
	peeker := newPeeker(tokens, false)
	parser := &parser{peeker: peeker}

	// Bare expressions are always parsed in  "ignore newlines" mode, as if
	// they were wrapped in parentheses.
	parser.PushIncludeNewlines(false)

	expr, parseDiags := parser.ParseExpression()
	diags = append(diags, parseDiags...)

	next := parser.Peek()
	if next.Type != TokenEOF && !parser.recovery {
		diags = append(diags, &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  "Extra characters after expression",
			Detail:   "An expression was successfully parsed, but extra characters were found after it.",
			Subject:  &next.Range,
		})
	}

	parser.PopIncludeNewlines()

	// Panic if the parser uses incorrect stack discipline with the peeker's
	// newlines stack, since otherwise it will produce confusing downstream
	// errors.
	peeker.AssertEmptyIncludeNewlinesStack()

	return expr, diags
}

// ParseTemplate parses the given buffer as a standalone HCL template,
// returning it as an instance of Expression.