aboutsummaryrefslogtreecommitdiff
path: root/cmd/repl
diff options
context:
space:
mode:
authorPřemysl Janouch <p@janouch.name>2018-10-09 10:37:56 +0200
committerPřemysl Janouch <p@janouch.name>2018-10-09 10:42:20 +0200
commitf751975cfd967c717473fea400d926a4c9f8beb1 (patch)
treea09b8095acdc5e535c345fbbc8a39248fc816168 /cmd/repl
parent55a107636733320f6ae84920a171799f102cefe1 (diff)
downloadell-f751975cfd967c717473fea400d926a4c9f8beb1.tar.gz
ell-f751975cfd967c717473fea400d926a4c9f8beb1.tar.xz
ell-f751975cfd967c717473fea400d926a4c9f8beb1.zip
Add a port to Go
Diffstat (limited to 'cmd/repl')
-rw-r--r--cmd/repl/main.go91
1 files changed, 91 insertions, 0 deletions
diff --git a/cmd/repl/main.go b/cmd/repl/main.go
new file mode 100644
index 0000000..e7f35fb
--- /dev/null
+++ b/cmd/repl/main.go
@@ -0,0 +1,91 @@
+//
+// Copyright (c) 2018, Přemysl Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+// Program repl is an interactive ell interpreter.
+package main
+
+import (
+ "fmt"
+ "io"
+ "os"
+ "strings"
+
+ // This library is rather simplistic but it's going to serve us fine.
+ "github.com/peterh/liner"
+
+ "janouch.name/ell/ell"
+)
+
+func run(L *ell.Ell, program *ell.V) {
+ var result *ell.V
+ if !L.EvalBlock(program, nil, &result) {
+ fmt.Printf("\x1b[31m%s: %s\x1b[0m\n", "runtime error", L.Error)
+ L.Error = ""
+ } else {
+ ell.PrintSeq(os.Stdout, result)
+ os.Stdout.WriteString("\n")
+ }
+}
+
+func complete(L *ell.Ell, line string) (res []string) {
+ // This never actually completes anything, just shows the options,
+ // we'd have to figure out the longest common prefix.
+ res = append(res, line)
+
+ line = strings.ToLower(line)
+ for v := L.Globals; v != nil; v = v.Next {
+ name := string(v.Head.String)
+ if strings.HasPrefix(strings.ToLower(name), line) {
+ res = append(res, name)
+ }
+ }
+ for name := range L.Native {
+ if strings.HasPrefix(strings.ToLower(name), line) {
+ res = append(res, name)
+ }
+ }
+ return
+}
+
+func main() {
+ L := ell.New()
+ if !ell.StdInitialize(L) {
+ fmt.Printf("runtime library initialization failed: %s\n", L.Error)
+ }
+
+ line := liner.NewLiner()
+ line.SetCompleter(func(line string) []string { return complete(L, line) })
+ line.SetMultiLineMode(true)
+ line.SetTabCompletionStyle(liner.TabPrints)
+
+ for {
+ script, err := line.Prompt("> ")
+ if err == nil {
+ line.AppendHistory(script)
+
+ p := ell.NewParser([]byte(script))
+ if program, err := p.Run(); err != nil {
+ fmt.Printf("\x1b[31m%s: %s\x1b[0m\n", "parse error", err)
+ } else {
+ run(L, program)
+ }
+ } else if err == liner.ErrPromptAborted || err == io.EOF {
+ break
+ } else {
+ fmt.Printf("\x1b[31m%s: %s\x1b[0m\n", "error", err)
+ }
+ }
+ os.Stdout.WriteString("\n")
+}