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package script
import (
"fmt"
"go/token"
"reflect"
"strings"
)
var Debug = false // print debug info?
// compileErr, and only compileErr will be caught by Compile and returned as an error.
type compileErr struct {
pos token.Pos
msg string
}
// implements error
func (c *compileErr) Error() string {
return c.msg
}
// constructs a compileErr
func err(pos token.Pos, msg ...interface{}) *compileErr {
str := fmt.Sprintln(msg...) // use Sprintln to insert spaces
str = str[:len(str)-1] // strip final \n
return &compileErr{pos, str}
}
// type string for value i
func typ(i interface{}) string {
typ := reflect.TypeOf(reflect.ValueOf(i).Interface()).String()
if strings.HasPrefix(typ, "*ast.") {
typ = typ[len("*ast."):]
}
return typ
}
func assert(test bool) {
if !test {
panic("assertion failed")
}
}
// decodes a token position in source to a line number
// and returns the line number + line code.
func pos2line(pos token.Pos, src string) string {
if pos == 0 {
return ""
}
lines := strings.Split(src, "\n")
line := 0
for i, b := range src {
if token.Pos(i) == pos {
return fmt.Sprint("line ", line, ": ", strings.Trim(lines[line], " \t")) // func{ prefix makes lines count from 1
}
if b == '\n' {
line++
}
}
return fmt.Sprint("position", pos) // we should not reach this
}
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