58 lines
1.2 KiB
Go
58 lines
1.2 KiB
Go
|
package participle
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"io"
|
||
|
|
"reflect"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Trace the parse to "w".
|
||
|
|
func Trace(w io.Writer) Option {
|
||
|
|
return func(p *Parser) error {
|
||
|
|
p.trace = w
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
type trace struct {
|
||
|
|
w io.Writer
|
||
|
|
indent int
|
||
|
|
node
|
||
|
|
}
|
||
|
|
|
||
|
|
func (t *trace) Parse(ctx *parseContext, parent reflect.Value) ([]reflect.Value, error) {
|
||
|
|
tok, _ := ctx.Peek(0)
|
||
|
|
fmt.Fprintf(t.w, "%s%q %s\n", strings.Repeat(" ", t.indent), tok, t.node.GoString())
|
||
|
|
return t.node.Parse(ctx, parent)
|
||
|
|
}
|
||
|
|
|
||
|
|
func injectTrace(w io.Writer, indent int, n node) node {
|
||
|
|
out := &trace{w, indent, n}
|
||
|
|
switch n := n.(type) {
|
||
|
|
case *disjunction:
|
||
|
|
for i, child := range n.nodes {
|
||
|
|
n.nodes[i] = injectTrace(w, indent+2, child)
|
||
|
|
}
|
||
|
|
case *strct:
|
||
|
|
n.expr = injectTrace(w, indent+2, n.expr)
|
||
|
|
case *sequence:
|
||
|
|
n.node = injectTrace(w, indent+2, n.node)
|
||
|
|
// injectTrace(w, indent, n.next)
|
||
|
|
case *parseable:
|
||
|
|
case *capture:
|
||
|
|
n.node = injectTrace(w, indent+2, n.node)
|
||
|
|
case *reference:
|
||
|
|
case *optional:
|
||
|
|
n.node = injectTrace(w, indent+2, n.node)
|
||
|
|
case *repetition:
|
||
|
|
n.node = injectTrace(w, indent+2, n.node)
|
||
|
|
case *negation:
|
||
|
|
n.node = injectTrace(w, indent+2, n.node)
|
||
|
|
case *literal:
|
||
|
|
case *group:
|
||
|
|
n.expr = injectTrace(w, indent+2, n.expr)
|
||
|
|
}
|
||
|
|
return out
|
||
|
|
}
|