fix some string bugs and make external-file-loading work

builtins.go

@@ -1,9 +1,12 @@
 package main
 
 import (
+	"bufio"
+	"bytes"
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"os"
 	"strings"
 )
@@ -44,6 +47,7 @@ func (b *Builtins) Semicolon(c *Context) func(string) error {
 // OpenComment puts the parser into an "ignore" mode
 func (b *Builtins) OpenComment(c *Context) func(string) error {
 	return func(next string) error {
+		c.Flags.SetFlag("StashImmediate", c.Flags.GetFlag("Immediate"))
 		for i := 0; i < len(next); i = i + 1 {
 			switch next[i] {
 			case ')':
@@ -70,24 +74,25 @@ func (b *Builtins) EOLComment(c *Context) func(string) error {
 // CloseComment resumes parsing by consuming itself and resetting the immediate flag
 func (b *Builtins) CloseComment(c *Context) func(string) error {
 	return func(_ string) error {
-		c.Flags.SetFlag("Immediate", false)
+		c.Flags.SetFlag("Immediate", c.Flags.GetFlag("StashImmediate"))
 		return nil
 	}
 }
 
 // OpenQuote consumes text until its closing pair to output
-func (b *Builtins) OpenQuote(out io.Writer, r *Stack, close byte) func(string) error {
+func (b *Builtins) OpenQuote(out io.Writer, c *Context, close byte) func(string) error {
 	if out == nil {
 		out = os.Stdout
 	}
 	return func(next string) error {
+		c.Flags.SetFlag("StashImmediate", c.Flags.GetFlag("Immediate"))
 		w := []byte{}
 		for i := 0; i < len(next); i = i + 1 {
 			switch next[i] {
 			case close:
 				fmt.Fprint(out, string(w))
-				j, _ := r.Pop()
-				r.Push(j + i - 1) // push the end-point onto the stack
+				j, _ := c.RStack.Pop()
+				c.RStack.Push(j + i - 1) // push the end-point onto the stack
 				return nil
 			default:
 				w = append(w, next[i])
@@ -101,10 +106,25 @@ func (b *Builtins) OpenQuote(out io.Writer, r *Stack, close byte) func(string) e
 // CloseQuote consumes itself.
 func (b *Builtins) CloseQuote(c *Context) func(string) error {
 	return func(next string) error {
+		c.Flags.SetFlag("Immediate", c.Flags.GetFlag("StashImmediate"))
 		return nil
 	}
 }
 
+// StringBuffer consumes text until its closing byte, then puts that value into the context's stringbuffer
+func (b *Builtins) StringBuffer(c *Context, close byte) func(string) error {
+	return func(next string) error {
+		var buff bytes.Buffer
+		err := b.OpenQuote(&buff, c, '"')(next)
+		if err != nil {
+			return err
+		}
+		s, err := ioutil.ReadAll(&buff)
+		c.StringBuffer = string(s)
+		return err
+	}
+}
+
 // Eq compares TOS and NOS and puts -1 on the stack if they're equal, 0 otherwise.
 func (b *Builtins) Eq(s *Stack) func(string) error {
 	return func(_ string) error {
@@ -755,3 +775,43 @@ func (b *Builtins) Fetch(c *Context) func(string) error {
 		return nil
 	}
 }
+
+// Load loads a library into the current working environment
+func (b *Builtins) Load(c *Context) func(string) error {
+	return func(_ string) error {
+		filename := strings.TrimSpace(c.StringBuffer)
+		if filename == "" {
+			return fmt.Errorf(`stringbuffer empty; try S" filename.prsp" LOAD`)
+		}
+
+		// store stacks
+		s, r, i := c.Stack, c.RStack, c.IfStack
+		c.Stack = &Stack{values: []int{}}
+		c.RStack = &Stack{values: []int{}}
+		c.IfStack = &Stack{values: []int{}}
+
+		f, err := os.Open(filename)
+		if err != nil {
+			return err
+		}
+		reader := bufio.NewReader(f)
+		scanner := bufio.NewScanner(reader)
+
+		for {
+			scan := scanner.Scan()
+			line := strings.TrimSpace(scanner.Text())
+			err = c.Eval(line + " ") // append a space to make sure we always close out our parse loop
+			if err != nil && !errors.Is(err, ErrExit) {
+				return fmt.Errorf("error in library evaluation: %v", err)
+			}
+			if scan == false {
+				break
+			}
+		}
+		// restore stacks
+		c.Stack = s
+		c.RStack = r
+		c.IfStack = i
+		return nil
+	}
+}

eval.go

@@ -8,13 +8,14 @@ import (
 
 // Context is a set of Dictionary + Stacks + Flags representing a runtime environment
 type Context struct {
-	Dictionary Dictionary
-	Stack      *Stack // main stack
-	RStack     *Stack // "return" stack, for handling loops/backward jumps
-	IfStack    *Stack // tracks nested branches
-	Flags      Flags
-	Words      []string
-	Memory     Memory
+	Dictionary   Dictionary
+	Stack        *Stack // main stack
+	RStack       *Stack // "return" stack, for handling loops/backward jumps
+	IfStack      *Stack // tracks nested branches
+	Flags        Flags
+	Words        []string
+	Memory       Memory
+	StringBuffer string
 }
 
 // Eval evaulates a given line, recursively descending into given words as needed
@@ -32,12 +33,9 @@ func (c *Context) Eval(line string) error {
 			}
 			// Is this a word we know?
 			w, _ := c.Dictionary.GetWord(sword)
-			// check if it's an IMMEDIATE mode toggle word
-			if !c.Flags.GetFlag("Immediate") {
-				c.Flags.SetFlag("Immediate", w.Immediate)
-			}
 
-			if !c.Flags.GetFlag("Immediate") {
+			// if we're not in immedate mode, and the word isn't immediate, add word to buffer and continue parsing
+			if !c.Flags.GetFlag("Immediate") && !w.Immediate {
 				c.Words = append(c.Words, sword)
 				word = []byte{}
 				continue

examples/example.prsp

@@ -0,0 +1,3 @@
+.( Loading )
+: CUBE DUP DUP * * ;
+: SQUARE DUP * ;

main.go

@@ -28,6 +28,7 @@ func main() {
 			intern:   map[int]int{},
 			nextFree: 1,
 		},
+		StringBuffer: "",
 	}
 
 	b := &Builtins{}
@@ -38,9 +39,11 @@ func main() {
 	dict.AddWord("(", Word{Name: "(", Impl: b.OpenComment(&c), Immediate: true})
 	dict.AddWord(")", Word{Name: ")", Impl: b.CloseComment(&c), Immediate: true})
 	dict.AddWord(`\`, Word{Name: `\`, Impl: b.EOLComment(&c), Immediate: true})
-	dict.AddWord(`."`, Word{Name: `."`, Impl: b.OpenQuote(os.Stdout, &rstack, '"')})
+	dict.AddWord(`."`, Word{Name: `."`, Impl: b.OpenQuote(os.Stdout, &c, '"')})
 	dict.AddWord(`"`, Word{Name: `"`, Impl: b.CloseQuote(&c)})
-	dict.AddWord(`.(`, Word{Name: `.(`, Impl: b.OpenQuote(os.Stdout, &rstack, ')'), Immediate: true})
+	dict.AddWord(`.(`, Word{Name: `.(`, Impl: b.OpenQuote(os.Stdout, &c, ')'), Immediate: true})
+	dict.AddWord(`S"`, Word{Name: `S"`, Impl: b.StringBuffer(&c, '"')})
+	dict.AddWord("LOAD", Word{Name: "LOAD", Impl: b.Load(&c)})
 	// math
 	dict.AddWord("+", Word{Name: "+", Impl: b.Add(&stack)})
 	dict.AddWord("-", Word{Name: "-", Impl: b.Sub(&stack)})