From 9c25ac21f98e333125bb43e02d854519923c7ddc Mon Sep 17 00:00:00 2001
From: Aidan <aidan@aidanis.online>
Date: Sun, 21 Jun 2020 12:46:25 -0700
Subject: [PATCH] changed table types to support implementing 'let', also
 integrated stdlib into repl

---
 ast/eval.go       |  4 ++--
 ast/func_table.go |  6 +++---
 ast/var_table.go  | 10 +++++-----
 cmd/repl.go       |  4 ++++
 stdlib/stdlib.go  | 50 ++---------------------------------------------
 5 files changed, 16 insertions(+), 58 deletions(-)

diff --git a/ast/eval.go b/ast/eval.go
index a443de3..7525fd5 100644
--- a/ast/eval.go
+++ b/ast/eval.go
@@ -34,7 +34,7 @@ func (t *Token) Eval(funcs FuncTable, vars VarTable) *Token {
 
         switch (t_.Tag) {
         case SYMBOL:
-            maybeToken := vars.GetVar(t_.Inner.(string))
+            maybeToken := GetVar(t_.Inner.(string), vars)
             if maybeToken != nil {
                 tok := maybeToken.Eval(funcs, vars)
                 if tok.Tag == LIST {
@@ -52,7 +52,7 @@ func (t *Token) Eval(funcs FuncTable, vars VarTable) *Token {
 
     ret := reduce(t)
     if ret.Tag == SYMBOL {
-        f := funcs.GetFunction(ret.Inner.(string))
+        f := GetFunction(ret.Inner.(string), funcs)
         if f == nil {
             if !eligibleForSystemCall {
                 log.Log(log.DEBUG,
diff --git a/ast/func_table.go b/ast/func_table.go
index 5e62df0..c88cf37 100644
--- a/ast/func_table.go
+++ b/ast/func_table.go
@@ -28,7 +28,7 @@ type Function struct {
     Args        int // TODO: Make this a list of expected types (TAGs)
 }
 
-type FuncTable map[string]*Function
+type FuncTable *map[string]*Function
 
 // TODO: Currently only checks arg list length
 func (f Function) ParseFunction(args *Token) bool {
@@ -64,8 +64,8 @@ func (f Function) CallFunction(args *Token, vt VarTable, ft FuncTable) *Token {
     return f.Function(args, vt, ft)
 }
 
-func (table FuncTable) GetFunction(arg string) *Function {
-    target, ok := table[arg]
+func GetFunction(arg string, table FuncTable) *Function {
+    target, ok := (*table)[arg]
     if !ok {
         log.Log(log.DEBUG,
                 "function " + arg + " not found",
diff --git a/ast/var_table.go b/ast/var_table.go
index 3a2d266..6886690 100644
--- a/ast/var_table.go
+++ b/ast/var_table.go
@@ -17,10 +17,10 @@
 
 package ast
 
-type VarTable map[string]*Token
+type VarTable *map[string]*Token
 
-func (vt VarTable) GetVar(arg string) *Token {
-    val, ok := vt[arg]
+func GetVar(arg string, vt VarTable) *Token {
+    val, ok := (*vt)[arg]
     if !ok {
         return nil
     }
@@ -30,11 +30,11 @@ func (vt VarTable) GetVar(arg string) *Token {
 
 // Library represents variables defined in inner scope
 // It is assumed library is ordered from innermost scope to outermost scope
-func GetVar(arg string, library []VarTable) *Token {
+func GetVarFromTables(arg string, library []VarTable) *Token {
     var res *Token
     res = nil
     for i := 0; i < len(library); i += 1 {
-        res = library[i].GetVar(arg)
+        res = GetVar(arg, library[i])
         if res != nil {
             // TODO: Log scope res was found in?
             break
diff --git a/cmd/repl.go b/cmd/repl.go
index 9fb6911..7678965 100644
--- a/cmd/repl.go
+++ b/cmd/repl.go
@@ -25,6 +25,7 @@ import (
     "strconv"
     "git.callpipe.com/aidan/shs/ast"
     "git.callpipe.com/aidan/shs/log"
+    "git.callpipe.com/aidan/shs/stdlib"
 )
 
 const (
@@ -53,6 +54,9 @@ func main() {
     var vars ast.VarTable
     var funcs ast.FuncTable
 
+    funcs = stdlib.GenFuncTable()
+    vars = &map[string]*ast.Token{}
+
     useHist := false
     var histFile *os.File
     var err error
diff --git a/stdlib/stdlib.go b/stdlib/stdlib.go
index 2394f54..43d24fa 100644
--- a/stdlib/stdlib.go
+++ b/stdlib/stdlib.go
@@ -19,11 +19,11 @@ package stdlib
 
 import (
     "git.callpipe.com/aidan/shs/ast"
-    "git.callpipe.com/aidan/shs/log"
 )
 
 func GenFuncTable() ast.FuncTable {
-    var stdlib = ast.FuncTable{
+    var stdlib ast.FuncTable
+    stdlib = &map[string]*ast.Function{
         "...": &ast.Function{
             Function: expand,
             Name:      "...",
@@ -41,49 +41,3 @@ func GenFuncTable() ast.FuncTable {
 
     return stdlib
 }
-
-// TODO: put list funcs in their own file
-
-/* EXPAND
- * Takes 1 element: a list
- * retuns a sequence of elements (list contents)
- * in event a not-list is passed in, returns the arg.
- */
-func expand(input *ast.Token, vars ast.VarTable, funcs ast.FuncTable) *ast.Token {
-    if input.Tag != ast.LIST {
-        log.Log(log.DEBUG, "expand called on not a list", "expand")
-        return input
-    }
-
-    return input.Inner.(*ast.Token)
-}
-
-/* L_APPEND (append from repl)
- * Appends N elements to the end of a list
- * Arg one is a list, next args are appended
- * if no args are a list, a list is made from all args
- */
-func l_append(input *ast.Token, vars ast.VarTable, funcs ast.FuncTable) *ast.Token {
-    src := input
-
-    if input.Tag != ast.LIST {
-        // TODO: Position, if I can figure out what to do with it
-        src = &ast.Token{Tag: ast.LIST, Inner: input}
-        return src
-    }
-
-    // deref inner first
-    i := src.Inner.(*ast.Token)
-    iter := &i
-    if *iter == nil {
-        src.Inner = input.Next
-        return src
-    }
-
-    for (*iter).Next != nil {
-        iter = &((*iter).Next)
-    }
-    (*iter).Next = input.Next
-
-    return src
-}