docs/builder/parser/line_parsers.go

100 lines
2.3 KiB
Go

package parser
import (
"encoding/json"
"strconv"
"strings"
)
// ignore the current argument. This will still leave a command parsed, but
// will not incorporate the arguments into the ast.
func parseIgnore(rest string) (*Node, error) {
return blankNode(), nil
}
func parseSubCommand(rest string) (*Node, error) {
_, child, err := parseLine(rest)
if err != nil {
return nil, err
}
return &Node{Children: []*Node{child}}, nil
}
// parse environment like statements. Note that this does *not* handle
// variable interpolation, which will be handled in the evaluator.
func parseEnv(rest string) (*Node, error) {
node := blankNode()
rootnode := node
strs := TOKEN_WHITESPACE.Split(rest, 2)
node.Value = QuoteString(strs[0])
node.Next = blankNode()
node.Next.Value = QuoteString(strs[1])
return rootnode, nil
return node, nil
}
// parses a whitespace-delimited set of arguments. The result is effectively a
// linked list of string arguments.
func parseStringsWhitespaceDelimited(rest string) (*Node, error) {
node := blankNode()
rootnode := node
for _, str := range TOKEN_WHITESPACE.Split(rest, -1) { // use regexp
node.Value = QuoteString(str)
node.Next = blankNode()
node = node.Next
}
return rootnode, nil
}
// parsestring just wraps the string in quotes and returns a working node.
func parseString(rest string) (*Node, error) {
return &Node{QuoteString(rest), nil, nil}, nil
}
// parseJSON converts JSON arrays to an AST.
func parseJSON(rest string) (*Node, error) {
var (
myJson []interface{}
next = blankNode()
orignext = next
)
if err := json.Unmarshal([]byte(rest), &myJson); err != nil {
return nil, err
}
for _, str := range myJson {
switch str.(type) {
case float64:
str = strconv.FormatFloat(str.(float64), 'G', -1, 64)
}
next.Value = QuoteString(str.(string))
next.Next = blankNode()
next = next.Next
}
return orignext, nil
}
// parseMaybeJSON determines if the argument appears to be a JSON array. If
// so, passes to parseJSON; if not, quotes the result and returns a single
// node.
func parseMaybeJSON(rest string) (*Node, error) {
rest = strings.TrimSpace(rest)
if strings.HasPrefix(rest, "[") {
node, err := parseJSON(rest)
if err == nil {
return node, nil
}
}
node := blankNode()
node.Value = QuoteString(rest)
return node, nil
}