// nextDecimalNumber64 returns the next number, which
// must fit in a non-negative int64.
func (p *Parser) nextDecimalNumber64() int64 {
ibase, obase := p.config.Base()
defer p.config.SetBase(ibase, obase)
p.config.SetBase(10, obase)
v, err := value.Parse(p.need(scan.Number).Text)
if err != nil {
p.errorf("%s", err)
}
var n int64 = -1
switch num := v.(type) {
case value.Int:
n = int64(num)
case value.BigInt:
// The Int64 method produces undefined results if
// the value is too large, so we must check.
if num.Int.Sign() < 0 || num.Int.Cmp(value.MaxBigInt63) > 0 {
p.errorf("value out of range: %v", v)
}
n = num.Int64()
}
if n < 0 {
p.errorf("value must be a positive integer: %v", v)
}
return n
}
func (p *Parser) nextDecimalNumber() int {
ibase, obase := p.config.Base()
defer p.config.SetBase(ibase, obase)
p.config.SetBase(10, obase)
v, err := value.Parse(p.need(scan.Number).Text)
if err != nil {
p.errorf("%s", err)
}
num, ok := v.(value.Int)
if !ok {
p.errorf("value must be an integer: %v", v)
}
return int(num)
}
// number
// integer
// rational
// variable
// '(' Expr ')'
func (p *Parser) number(tok scan.Token) value.Expr {
var expr value.Expr
text := tok.Text
switch tok.Type {
case scan.Identifier:
expr = p.variable(text)
case scan.Number, scan.Rational:
var err error
expr, err = value.Parse(text)
if err != nil {
p.errorf("%s: %s", text, err)
}
case scan.LeftParen:
expr = p.expr(p.next())
tok := p.next()
if tok.Type != scan.RightParen {
p.errorf("expected right paren, found %s", tok)
}
}
return expr
}
// number
// integer
// rational
// string
// variable
// '(' Expr ')'
// If the value is a string, value.Expr is nil.
func (p *Parser) number(tok scan.Token) (expr value.Expr, str string) {
var err error
text := tok.Text
switch tok.Type {
case scan.Identifier:
expr = p.variable(text)
case scan.String:
str = value.ParseString(text)
case scan.Number, scan.Rational:
expr, err = value.Parse(p.context.Config(), text)
case scan.LeftParen:
expr = p.expr(p.next())
tok := p.next()
if tok.Type != scan.RightParen {
p.errorf("expected right paren, found %s", tok)
}
}
if err != nil {
p.errorf("%s: %s", text, err)
}
return expr, str
}
return value.Binary(b.left.Eval(context), b.op, b.right.Eval(context))
}
// Parser stores the state for the ivy parser.
type Parser struct {
scanner *scan.Scanner
config *config.Config
fileName string
lineNum int
errorCount int // Number of errors.
peekTok scan.Token
curTok scan.Token // most recent token from scanner
context *execContext
}
var zero, _ = value.Parse("0")
// NewParser returns a new parser that will read from the scanner.
// The context must have have been created by this package's NewContext function.
func NewParser(conf *config.Config, fileName string, scanner *scan.Scanner, context value.Context) *Parser {
return &Parser{
scanner: scanner,
config: conf,
fileName: fileName,
context: context.(*execContext),
}
}
func (p *Parser) next() scan.Token {
tok := p.peekTok
if tok.Type != scan.EOF {