prototype repl

ast/eval.go

@@ -17,6 +17,8 @@
 
 package ast
 
+import "git.callpipe.com/aidan/shs/log"
+
 func (t *Token) Eval(funcs FuncTable, vars VarTable) *Token {
     if t == nil {
         return nil
@@ -53,7 +55,9 @@ func (t *Token) Eval(funcs FuncTable, vars VarTable) *Token {
         f := funcs.GetFunction(ret.Inner.(string))
         if f == nil {
             if !eligibleForSystemCall {
-                // TODO: log error
+                log.Log(log.DEBUG,
+                    "could not find definition for symbol " + ret.Inner.(string), 
+                    "eval")
                 return nil
             }
 
@@ -61,7 +65,7 @@ func (t *Token) Eval(funcs FuncTable, vars VarTable) *Token {
             return nil // TODO: Thats gotta change
         }
 
-        return (*f).CallFunction(ret.Next)
+        return (*f).CallFunction(ret.Next, vars, funcs)
     }
 
     return ret

ast/func_table.go

@@ -21,6 +21,7 @@ type Operation func(*Token) *Token
 
 type Function struct {
     function    Operation
+    name        string
     timesCalled int
     args        int // TODO: Make this a list of expected types (TAGs)
 }
@@ -40,7 +41,9 @@ func (f Function) ParseFunction(args *Token) bool {
     }
 
     if i != 0 {
-        // TODO: log error here
+        log.Log(log.ERR, 
+                "Incorrect number of arguments",
+                "eval")
         return false
     }
 
@@ -49,6 +52,9 @@ func (f Function) ParseFunction(args *Token) bool {
 
 func (f Function) CallFunction(args *Token) *Token {
     if !f.ParseFunction(args) {
+        log.Log(log.Err,
+                "Couldnt call " + f.name,
+                "eval")
         return nil
     }
 
@@ -59,6 +65,9 @@ func (f Function) CallFunction(args *Token) *Token {
 func (table FuncTable) GetFunction(arg string) *Function {
     target, ok := table[arg]
     if !ok {
+        log.Log(log.DEBUG,
+                "function " + arg + " not found",
+                "eval")
         return nil
     }
 

ast/token.go

@@ -164,11 +164,17 @@ error:
     // TODO: Hook into error module
     // TODO: Finalize and GC alloced tokens
     if start_pos == -1 {
-        println("[-] Unmatched string delimiter in input. discarding.")
+        log.Log(log.ERR,
+                "Unmatched string delimiter in input. discarding.",
+                "lex")
     } else if start_pos == -2 {
-        println("[-] Unmatched list delimiter in input. discarding.")
+        log.Log(log.ERR,
+                "Unmatched list delimiter in input. discarding.",
+                "lex")
     } else {
-        println("[-] Unknown error in input. discarding.")
+        log.Log(log.ERR,
+                "Unknown error in input. discarding.",
+                "lex")
     }
 
     return nil

cmd/print_ast.go

@@ -20,10 +20,10 @@ package main
 import (
     "strings"
     "os"
-    "git.callpipe.com/aidan/shs/io"
+    "git.callpipe.com/aidan/shs/log"
     "git.callpipe.com/aidan/shs/ast"
 )
 
 func main() {
-    io.PrintSExpression(ast.Lex(strings.Join(os.Args[1:], " ")))
+    log.PrintSExprsIndividually(ast.Lex(strings.Join(os.Args[1:], " ")))
 }

cmd/repl.go

@@ -0,0 +1,106 @@
+/*   SHS: Syntactically Homogeneous Shell
+ *   Copyright (C) 2019  Aidan Hahn
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package main
+
+import (
+    "fmt"
+    "bufio"
+    "strconv"
+    "git.callpipe.com/aidan/shs/ast"
+    "git.callpipe.com/aidan/shs/log"
+)
+
+const (
+    def_prompt  string = "λ"
+)
+
+func setLogLvl() {
+    loglvl := os.Getenv("SH_LOGGING")
+    if loglvl != "" {
+        llvl, ok := strconv.ParseInt(loglvl, 10, 8)
+        if !ok {
+            log.Log(log.Err,
+                    "couldnt parse log level",
+                    "init")
+        } else {
+            log.SetLogLvl(llvl)
+        }
+    }
+}
+
+func main() {
+    debug  := os.Getenv("SH_DEBUG_MODE")
+    hist   := os.Getenv("SH_HIST_FILE")
+    prompt := os.Getenv("SHS_SH_PROMPT")
+
+    var vars ast.VarTable
+    var funcs ast.VarTable
+
+    useHist := false
+    var histFile os.File
+    var err error
+
+    if hist != "" {
+        useHist = true
+        histFile, err = os.OpenFile(histFile, os.O_RDWR|os.O_CREATE, 0755)
+        if err != nil {
+            useHist = false
+            log.Log(log.ERR, "coudlnt open histfile: " + err, "init")
+        }
+    }
+
+    if prompt == "" {
+        prompt = def_prompt
+    }
+
+    // TODO: is bufio right for this?
+    reader := bufio.NewReader(os.Stdin)
+    for {
+        setLogLvl()
+        fmt.Print(prompt + " ")
+        text, err := reader.ReadString('\n')
+        if err != nil {
+            log.Log(log.ERR, "couldnt read user input: " + err, "repl")
+        }
+
+        // TODO: replace with a regex
+        text = strings.Replace(text, "\r\n", "", -1)
+        text = strings.Replace(text, "\n", "", -1)
+
+        if useHist {
+            _, err  = histFile.Write([]byte(text + "\n"))
+            if err != nil {
+                log.Log(log.DEBUG, "couldnt write to histfile: " + err, "repl")
+            }
+        }
+
+        userInput := ast.Lex(text)
+        if userInput == nil {
+            // errors handled in Lex
+            // TODO: return an error instead
+            continue
+        }
+
+        if debug != "" {
+            log.PrintSExprsIndividually(userInput)
+        }
+
+        result := userInput.Eval(funcs, vars)
+        fmt.Println(result.String() + "\n")
+    }
+}

log/logger.go

@@ -0,0 +1,44 @@
+/*   SHS: Syntactically Homogeneous Shell
+ *   Copyright (C) 2019  Aidan Hahn
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package log
+
+import (
+    "fmt"
+)
+
+const (
+    ERR     int = 0
+    DEBUG   int = 1
+    INFO    int = 2
+)
+
+var logLevel int
+
+func SetLogLvl(lvl int) {
+    if lvl < 4 && lvl > 0 {
+        logLevel = lvl
+    }
+}
+
+func Log(lvl int, msg, context string) {
+    if lvl > logLevel {
+        return
+    }
+
+    fmt.Println("[" + context + "] " + msg)
+}

log/print.go

@@ -15,7 +15,7 @@
  *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-package io
+package log
 
 import (
     "strings"
@@ -24,6 +24,61 @@ import (
     "git.callpipe.com/aidan/shs/datatypes"
 )
 
+/* Print function which is better suited for repl.
+ * This one prints the SEXPRs as one would write them.
+ */
+func (t *ast.Token) String() string {
+    switch tag {
+    case ast.STRING
+        return "\"" + t.Inner.(string) + "\""
+
+    case ast.NUMBER:
+        return t.Inner.(string)
+
+    case ast.LIST:
+        repr := "("
+        for i := t.Inner.(*ast.Token); i != nil; i = i.Next {
+            repr = repr + i.String() + " "
+        }
+        return repr + ")"
+
+    case ast.SYMBOL:
+        return "<" + t.Inner.(string) + ">"
+    }
+}
+
+/* Print function which breaks each embedded list out on individual lines.
+ * Used in the print_ast debug tool. not too useful for repl applications.
+ * Very useful for debugging syntax though.
+ * TODO: Add numbers to denote embedded scope?
+ */
+func PrintSExprsIndividually(arg *ast.Token) {
+    if arg == nil {
+        return //TODO: Handle error here?
+    }
+
+    var lists datatypes.TokenStack;
+    lists.Push(arg)
+
+loop:
+    var constructor strings.Builder
+    i := lists.Pop()
+    if i == nil {
+        return
+    }
+
+    for iter := i; iter != nil; iter = iter.Next {
+        if iter.Tag == ast.LIST {
+            lists.Push(iter.Inner.(*ast.Token))
+        }
+
+        constructor.WriteString(FmtToken(iter))
+    }
+
+    println(constructor.String())
+    goto loop
+}
+
 func FmtToken(arg *ast.Token) string {
     suffix := "->"
     if arg.Next == nil {
@@ -53,29 +108,3 @@ func GetTagAsStr(tag ast.Token_t) string {
     return "UNKNOWN"
 }
 
-func PrintSExpression(arg *ast.Token) {
-    if arg == nil {
-        return //TODO: Handle error here?
-    }
-
-    var lists datatypes.TokenStack;
-    lists.Push(arg)
-
-loop:
-    var constructor strings.Builder
-    i := lists.Pop()
-    if i == nil {
-        return
-    }
-
-    for iter := i; iter != nil; iter = iter.Next {
-        if iter.Tag == ast.LIST {
-            lists.Push(iter.Inner.(*ast.Token))
-        }
-
-        constructor.WriteString(FmtToken(iter))
-    }
-
-    println(constructor.String())
-    goto loop
-}