added

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

@@ -0,0 +1,150 @@
+package zygo
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+// alternative. simpler, currently panics.
+func SimpleSourceFunction(env *Zlisp, name string, args []Sexp) (Sexp, error) {
+	if len(args) != 1 {
+		return SexpNull, WrongNargs
+	}
+
+	src, isStr := args[0].(*SexpStr)
+	if !isStr {
+		return SexpNull, fmt.Errorf("-> error: first argument must be a string")
+	}
+
+	file := src.S
+	if !FileExists(file) {
+		return SexpNull, fmt.Errorf("path '%s' does not exist", file)
+	}
+
+	env2 := env.Duplicate()
+
+	f, err := os.Open(file)
+	if err != nil {
+		return SexpNull, err
+	}
+	defer f.Close()
+
+	err = env2.LoadFile(f)
+	if err != nil {
+		return SexpNull, err
+	}
+
+	_, err = env2.Run()
+
+	return SexpNull, err
+}
+
+// existing
+
+// SourceExpressions, this should be called from a user func context
+func (env *Zlisp) SourceExpressions(expressions []Sexp) error {
+	gen := NewGenerator(env)
+
+	err := gen.GenerateBegin(expressions)
+	if err != nil {
+		return err
+	}
+	//P("debug: in SourceExpressions, FROM expressions='%s'", (&SexpArray{Val: expressions, Env: env}).SexpString(0))
+	//P("debug: in SourceExpressions, gen=")
+	//DumpFunction(ZlispFunction(gen.instructions), -1)
+	curfunc := env.curfunc
+	curpc := env.pc
+
+	env.curfunc = env.MakeFunction("__source", 0, false,
+		gen.instructions, nil)
+	env.pc = 0
+
+	result, err := env.Run()
+	if err != nil {
+		return err
+	}
+
+	//P("end of SourceExpressions, result going onto datastack is: '%s'", result.SexpString(0))
+	env.datastack.PushExpr(result)
+
+	//P("debug done with Run in source, now stack is:")
+	//env.datastack.PrintStack()
+
+	env.pc = curpc
+	env.curfunc = curfunc
+
+	return nil
+}
+
+func (env *Zlisp) SourceStream(stream io.RuneScanner) error {
+	env.parser.ResetAddNewInput(stream)
+	expressions, err := env.parser.ParseTokens()
+	if err != nil {
+		return errors.New(fmt.Sprintf(
+			"Error parsing on line %d: %v\n", env.parser.lexer.Linenum(), err))
+	}
+
+	return env.SourceExpressions(expressions)
+}
+
+func (env *Zlisp) SourceFile(file *os.File) error {
+	return env.SourceStream(bufio.NewReader(file))
+}
+
+func SourceFileFunction(env *Zlisp, name string, args []Sexp) (Sexp, error) {
+	if len(args) < 1 {
+		return SexpNull, WrongNargs
+	}
+
+	for _, v := range args {
+		if err := env.sourceItem(v); err != nil {
+			return SexpNull, err
+		}
+	}
+
+	result, err := env.datastack.PopExpr()
+	if err != nil {
+		return SexpNull, err
+	}
+	return result, nil
+}
+
+// helper for SourceFileFunction recursion
+func (env *Zlisp) sourceItem(item Sexp) error {
+	switch t := item.(type) {
+	case *SexpArray:
+		for _, v := range t.Val {
+			if err := env.sourceItem(v); err != nil {
+				return err
+			}
+		}
+	case *SexpPair:
+		expr := item
+		for expr != SexpNull {
+			list := expr.(*SexpPair)
+			if err := env.sourceItem(list.Head); err != nil {
+				return err
+			}
+			expr = list.Tail
+		}
+	case *SexpStr:
+		var f *os.File
+		var err error
+
+		if f, err = os.Open(t.S); err != nil {
+			return err
+		}
+		defer f.Close()
+		if err = env.SourceFile(f); err != nil {
+			return err
+		}
+
+	default:
+		return fmt.Errorf("source: Expected `string`, `list`, `array`. Instead found type %T val %v", item, item)
+	}
+
+	return nil
+}