added

vendor/github.com/glycerine/zygomys/zygo/regexp.go

@@ -0,0 +1,100 @@
+package zygo
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+)
+
+type SexpRegexp regexp.Regexp
+
+func (re *SexpRegexp) SexpString(ps *PrintState) string {
+	r := (*regexp.Regexp)(re)
+	return fmt.Sprintf(`(regexpCompile "%v")`, r.String())
+}
+
+func (r *SexpRegexp) Type() *RegisteredType {
+	return nil // TODO what should this be?
+}
+
+func regexpFindIndex(env *Zlisp,
+	needle *regexp.Regexp, haystack string) (Sexp, error) {
+
+	loc := needle.FindStringIndex(haystack)
+
+	arr := make([]Sexp, len(loc))
+	for i := range arr {
+		arr[i] = Sexp(&SexpInt{Val: int64(loc[i])})
+	}
+
+	return &SexpArray{Val: arr, Env: env}, nil
+}
+
+func RegexpFind(env *Zlisp, name string,
+	args []Sexp) (Sexp, error) {
+	if len(args) != 2 {
+		return SexpNull, WrongNargs
+	}
+	var haystack string
+	switch t := args[1].(type) {
+	case *SexpStr:
+		haystack = t.S
+	default:
+		return SexpNull,
+			errors.New(fmt.Sprintf("2nd argument of %v should be a string", name))
+	}
+
+	var needle *regexp.Regexp
+	switch t := args[0].(type) {
+	case *SexpRegexp:
+		needle = (*regexp.Regexp)(t)
+	default:
+		return SexpNull,
+			errors.New(fmt.Sprintf("1st argument of %v should be a compiled regular expression", name))
+	}
+
+	switch name {
+	case "regexpFind":
+		str := needle.FindString(haystack)
+		return &SexpStr{S: str}, nil
+	case "regexpFindIndex":
+		return regexpFindIndex(env, needle, haystack)
+	case "regexpMatch":
+		matches := needle.MatchString(haystack)
+		return &SexpBool{Val: matches}, nil
+	}
+
+	return SexpNull, errors.New("unknown function")
+}
+
+func RegexpCompile(env *Zlisp, name string,
+	args []Sexp) (Sexp, error) {
+	if len(args) < 1 {
+		return SexpNull, WrongNargs
+	}
+
+	var re string
+	switch t := args[0].(type) {
+	case *SexpStr:
+		re = t.S
+	default:
+		return SexpNull,
+			errors.New("argument of regexpCompile should be a string")
+	}
+
+	r, err := regexp.Compile(re)
+
+	if err != nil {
+		return SexpNull, errors.New(
+			fmt.Sprintf("error during regexpCompile: '%v'", err))
+	}
+
+	return Sexp((*SexpRegexp)(r)), nil
+}
+
+func (env *Zlisp) ImportRegex() {
+	env.AddFunction("regexpCompile", RegexpCompile)
+	env.AddFunction("regexpFindIndex", RegexpFind)
+	env.AddFunction("regexpFind", RegexpFind)
+	env.AddFunction("regexpMatch", RegexpFind)
+}