Adds import support

env.go

@@ -18,6 +18,7 @@ import (
 
 type env struct {
 	vars    map[string]token
+	imports map[string]bool
 	parent  *env
 }
 
@@ -32,6 +33,16 @@ func (e *env) Find(s string) (*env, error) {
 	}
 }
 
+func (e *env) Imported(s string) bool {
+	if _, ok := e.imports[s]; ok {
+		return true
+	} else if e.parent == nil {
+		return false
+	} else {
+		return e.parent.Imported(s)
+	}
+}
+
 func (e *env) UpLevel(count int) *env {
 	var en *env = e
 	for ; count > 0; count-- {
@@ -47,5 +58,5 @@ func (e *env) Add(name string, t token) {
 }
 
 func NewEnv(parent *env) *env {
-	return &env{make(map[string]token), parent}
+	return &env{make(map[string]token), make(map[string]bool), parent}
 }

globals.go

@@ -46,4 +46,5 @@ var (
 	// This is the main stack for the language
 	globalStack stack = NewStack()
 	globalRetStack stack = NewStack()
+	imports = make(map[string]bool)
 )

helpers.go

@@ -116,7 +116,7 @@ func isKeyword(s string) bool {
 		"list-set!", "split", "join", "file-write", "file-remove",
 		"file-exists?", "file-read", "docstring!", "input", "re-match?",
 		"re-find", "re-replace", "slice", "stackdepth", "net-get", "try",
-		"catch", "throw":
+		"catch", "throw", "import":
 		  return true
 		default:
 			return false

keywords.go

@@ -113,6 +113,8 @@ func callKeyword(kw token, r *tokenReader, en *env) error {
 		return libNetGet(kw.line, kw.file)
 	case "throw":
 		return libThrow(kw.line, kw.file)
+	case "import":
+		return libImport(kw.line, kw.file, en)
 	default:
 		return fmt.Errorf("Unknown keyword: `%s`", kw.line, kw.val.(string))
 	}
@@ -1271,3 +1273,58 @@ func libThrow(line int, fp string) error {
 	return fmt.Errorf("%s", toString(e, false))
 }
 
+func libImport(line int, fp string, en *env) error {
+	t, err := globalStack.Pop()
+	if err != nil {
+		return err
+	}
+	if t.kind != STRING {
+		return fmt.Errorf("`import` expects a STRING on TOS, not %s", kindToString(t.kind))
+	}
+	// Use 'imports' var (found in globals.go) to mark once imported
+	// XXX scratch that. Add a map to the env struct and mark them there
+	// so that they can get imported wherever in scope, but never doubly
+	// so? A way to search parent scopes for the value will be important
+	// as well
+	if en.Imported(t.val.(string)) {
+		return nil
+	}
+	switch t.val.(string) {
+	case "std":
+		err = lexParseInterpret(stdImport, en, "std")
+		if err != nil {
+			return err
+		}
+		en.imports[t.val.(string)] = true
+	case "math":
+		err = lexParseInterpret(mathImport, en, "math")
+		if err != nil {
+			return err
+		}
+		en.imports[t.val.(string)] = true
+	case "stack":
+		err = lexParseInterpret(stackImport, en, "stack")
+		if err != nil {
+			return err
+		}
+		en.imports[t.val.(string)] = true
+	case "io":
+		err = lexParseInterpret(ioImport, en, "io")
+		if err != nil {
+			return err
+		}
+		en.imports[t.val.(string)] = true
+	default:
+		p := ExpandedAbsFilepath(t.val.(string))
+		s, err := readFile(p)
+		if err != nil {
+			return err
+		}
+		err = lexParseInterpret(s, en, p)
+		if err != nil {
+			return err
+		}
+		en.imports[t.val.(string)] = true
+	}
+	return nil
+}

lib/io.fe

@@ -0,0 +1,28 @@
+STRING var! stdout
+"/dev/fd/1" set! stdout 
+
+STRING var! stderr
+"/dev/fd/2" set! stderr
+
+STRING var! stdin
+"/dev/fd/0" set! stdin
+
+STRING var! devnull
+"/dev/null" set! devnull
+
+proc print
+  | Stack: ANY
+Read :
+Push :
+Notes: Prints the value on TOS |
+  STRING cast stdout file-write
+.
+
+proc println
+  | Stack: ANY
+Read :
+Push :
+Notes: Prints the value on TOS + a newline |
+  STRING cast "\n" append stdout file-write
+.
+

lib/math.fe

@@ -0,0 +1,52 @@
+"std"   import
+"stack" import
+
+proc abs
+  | Stack: FLOAT/INT
+Read :
+Push : FLOAT/INT
+Notes: Takes TOS and leaves it's absolute value on TOS |
+  dup 0 <
+	if
+	 -1 *
+	.
+.
+
+proc %
+  | Stack: INT
+Read :
+Push : INT
+Notes: Calculates the remainder (n1 n2 -- n3) |
+	dup2
+  INT var! div
+	FLOAT cast / INT cast set! div
+  div * -
+.
+
+proc ipow
+  | Stack: INT INT
+Read :
+Push : INT
+Notes: Raise n1 by n2 (n1 n2 -- n3) |
+  INT var! exp INT cast set! exp
+  INT var! base INT cast set! base
+	exp 0 < if
+	  "`pow` with negative exponent not allowed" throw .
+	INT var! result 1 set! result
+	proc loop? exp 0 > .
+	loop? while
+	  result base * set! result
+		--! exp
+		loop?
+	.
+	result
+.
+
+proc square
+  | Stack: INT
+Read :
+Push : INT
+Notes: Squares the given INT and leaves the result on TOS |
+ dup *
+.
+

lib/stack.fe

@@ -0,0 +1,17 @@
+
+proc dup2
+  | Stack: ANY1 ANY2
+Read :
+Push : ANY1 ANY2
+Notes: Duplicates the top two stack values such that the stack starts and ends as: v1 v2 -- v1 v2 v1 v2 |
+  over over
+.
+
+proc nip
+  | Stack: ANY1 ANY2
+Read :
+Push :
+Notes: Drops the item under TOS (a1 a2 -- a2) |
+  swap drop
+.
+

lib/std.fe

@@ -1,17 +1,3 @@
-
-STRING var! stdout
-"/dev/fd/1" set! stdout 
-
-STRING var! stderr
-"/dev/fd/2" set! stderr
-
-STRING var! stdin
-"/dev/fd/0" set! stdin
-
-STRING var! devnull
-"/dev/null" set! devnull
-
-
 proc! ++!
   | Stack:
 Read : SYMBOL(INT)
@@ -68,56 +54,6 @@ Notes: Decrements an INT on TOS and places the result back on TOS |
 	.
 .
 
-proc print
-  | Stack: ANY
-Read :
-Push :
-Notes: Prints the value on TOS |
-  STRING cast stdout file-write
-.
-
-proc println
-  | Stack: ANY
-Read :
-Push :
-Notes: Prints the value on TOS + a newline |
-  STRING cast "\n" append stdout file-write
-.
-
-proc abs
-  | Stack: FLOAT/INT
-Read :
-Push : FLOAT/INT
-Notes: Takes TOS and leaves it's absolute value on TOS |
-  dup TYPE cast var! v
-	set! v
-	v 0 <
-	if
-	 v -1 *
-	else
-	 v
-	.
-.
-
-proc dup2
-  | Stack: ANY1 ANY2
-Read :
-Push : ANY1 ANY2
-Notes: Duplicates the top two stack values such that the stack starts and ends as: v1 v2 -- v1 v2 v1 v2 |
-  over over
-.
-
-proc %
-  | Stack: INT
-Read :
-Push : INT
-Notes: Calculates the remainder (n1 n2 -- n3) |
-	dup2
-  INT var! div
-	FLOAT cast / INT cast set! div
-  div * -
-.
-
 proc not
   | Stack: ANY
 Read :
@@ -126,37 +62,4 @@ Notes: Treats TOS as a BOOL (regardless of actual type) and inverts the BOOL |
   if false else true .
 .
 
-proc ipow
-  | Stack: INT INT
-Read :
-Push : INT
-Notes: Raise n1 by n2 (n1 n2 -- n3) |
-  INT var! exp INT cast set! exp
-  INT var! base INT cast set! base
-	exp 0 < if
-	  "`pow` with negative exponent not allowed" throw .
-	INT var! result 1 set! result
-	proc loop? exp 0 > .
-	loop? while
-	  result base * set! result
-		--! exp
-		loop?
-	.
-	result
-.
 
-proc square
-  | Stack: INT
-Read :
-Push : INT
-Notes: Squares the given INT and leaves the result on TOS |
- dup *
-.
-
-proc nip
-  | Stack: ANY1 ANY2
-Read :
-Push :
-Notes: Drops the item under TOS (a1 a2 -- a2) |
-  swap drop
-.

main.go

@@ -45,8 +45,16 @@ var completions = []string{
 	}
 
 //go:embed lib/std.fe
-var std string
+var stdImport string
 
+//go:embed lib/math.fe
+var mathImport string
+
+//go:embed lib/io.fe
+var ioImport string
+
+//go:embed lib/stack.fe
+var stackImport string
 
 
 /*
@@ -94,11 +102,6 @@ func VersionString() string {
 	return fmt.Sprintf("%.2f\n", version)
 }
 
-func seedBaseEnv(en *env) {
-	lexParseInterpret(std, en, "std.fe")
-}
-
-
 func repl() {
 	fmt.Printf("%s\nfelise version %s(c) 2023 sloum, all rights reserved\nLicensed under the terms of the Floodgap Free Software License\n(`bye` or `exit` to quit)\n\n", logo,VersionString())
 	initialTerm, _ = ln.TerminalMode()
@@ -125,7 +128,6 @@ func repl() {
 	var text strings.Builder
 	var cont bool
 	baseEnv := NewEnv(nil)
-	seedBaseEnv(baseEnv)
 
 	for {
 		if linerTerm != nil {
@@ -149,22 +151,28 @@ func repl() {
 			text.WriteString(in)
 		}
 		if !cont {
-			lexParseInterpret(text.String(), baseEnv, "")
+			processInterpretError(lexParseInterpret(text.String(), baseEnv, ""), "")
 			text.Reset()
 		}
 	}
 }
 
-func lexParseInterpret(s string, en *env, file string) {
+func lexParseInterpret(s string, en *env, file string) error {
 	lexedTokens, err := lex(s, file)
 	if err == nil {
 		r := NewTokenReader(lexedTokens)
 		var parsedTokens []token
-		parsedTokens, err := parse(r)
+		parsedTokens, err = parse(r)
 		if err == nil {
 			err = interpret(parsedTokens, en)
 		}
 	}
+	return err
+}
+// TODO just separated lex and process err
+// Make sure all is working
+
+func processInterpretError(err error, file string) {
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "ERROR | %s\n", err.Error())
 		if file == "" {
@@ -173,7 +181,7 @@ func lexParseInterpret(s string, en *env, file string) {
 			os.Exit(1)
 		}
 	} else if file == "" {
-			fmt.Println("\n\033[0mOk.")
+		fmt.Println("\n\033[0mOk.")
 	}
 }
 
@@ -194,7 +202,6 @@ func main() {
 			os.Exit(1)
 		}
 		en := NewEnv(nil)
-		seedBaseEnv(en)
 		if len(flagArgs) > 1 {
 			t := make([]token, len(flagArgs)-1)
 			for i, s := range flagArgs[1:] {
@@ -205,7 +212,7 @@ func main() {
 			t := make([]token, 0)
 			en.Add("sys-args", token{LIST, list{t}, -1, "built-in"})
 		}
-		lexParseInterpret(s, en, flagArgs[0])
+		processInterpretError(lexParseInterpret(s, en, flagArgs[0]), flagArgs[0])
 	} else {
 		repl()
 	}