path: root/src/texec/eval.go

/*
	Copyright 2020 Kyle Gunger

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

		http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
*/

package texec

import (
	"tparse"
	"fmt"
	"strconv"
	"strings"
)

/*
	So here's what I care to support at present:
	Type checking, basic types, writing to stdout or a file
	Variable and state contexts
	Reading from files
	Raw structs
	Appending to arrays
	Calling functions and methods
	libtnsl stub

	This subset should theoretically be enough to write a compiler.
*/

var (
	// Program to run
	prog *TModule
	// Current artifact
	cart TArtifact

	//Default null value
	null = TVariable{tNull, nil}
)

//################
//# Helper Funcs #
//################

// Error helper

func errOut(msg string) {
	fmt.Println("==== BEGIN ERROR ====")
	fmt.Println(msg)
	fmt.Println(cart)
	fmt.Println("==== END ERROR ====")
	panic(">>> PANIC FROM EVAL <<<")
}

func errOutCTX(msg string, ctx *VarMap) {
	fmt.Println("==== BEGIN ERROR ====")
	fmt.Println(msg)
	fmt.Println(cart)
	fmt.Println(*ctx)
	fmt.Println("====  END  ERROR ====")
	panic(">>> PANIC FROM EVAL <<<")
}

func errOutNode(msg string, n tparse.Node) {
	fmt.Println("==== BEGIN ERROR ====")
	fmt.Println(msg)
	fmt.Println(cart)
	fmt.Printf("Line: %v Char: %v\n", n.Data.Line, n.Data.Char)
	fmt.Println("====  END  ERROR ====")
	panic(">>> PANIC FROM EVAL <<<")
}

// Names of artifacts, finding artifacts

func getDefNames(def tparse.Node) []string {
	out := []string{}
	for i := 0; i < len(def.Sub); i++ {
		if def.Sub[i].Data.Data == "vlist" && def.Sub[i].Data.Type == 10 {
			vl := def.Sub[i]
			for i := 0; i < len(vl.Sub); i++ {
				if vl.Sub[i].Data.Type == tparse.DEFWORD {
					out = append(out, vl.Sub[i].Data.Data)
				} else if vl.Sub[i].Data.Data == "=" && vl.Sub[i].Sub[0].Data.Type == tparse.DEFWORD {
					out = append(out, vl.Sub[i].Sub[0].Data.Data)
				}
			}
		}
	}
	return out
}

func getBlockName(block tparse.Node) []string {
	out := []string{}
	for i := 0; i < len(block.Sub[0].Sub); i++ {
		if block.Sub[0].Sub[i].Data.Type == tparse.DEFWORD {
			out = append(out, block.Sub[0].Sub[i].Data.Data)
		} else if block.Sub[0].Sub[i].Data.Data == "method" {
			out = append(out, block.Sub[0].Sub[i].Sub[0].Data.Data)
		} else if block.Sub[0].Sub[i].Data.Type == tparse.KEYWORD {
			switch block.Sub[0].Sub[i].Data.Data {
			case "if", "else", "loop", "match", "case", "default":
				out = append(out, block.Sub[0].Sub[i].Data.Data)
			default:
			}
		}
	}
	return out
}

func getTypeName(t tparse.Node) []string {
	out := []string{}
	for i := 0; i < len(t.Sub); i++ {
		if t.Sub[i].Data.Type == tparse.DEFWORD {
			out = append(out, t.Sub[i].Data.Data)
		}
	}
	return out
}

// Get the list of names defined by the block or variable definition
func getNames(root tparse.Node) []string {
	switch root.Data.Data {
	case "block":
		return getBlockName(root)
	case "define":
		return getDefNames(root)
	case "raw", "struct", "enum":
		return getTypeName(root)
	}

	return []string{}
}

// Attempt to get a module from a path starting at the given module
// Returns nil if the module was not found.
func getModuleRelative(mod *TModule, a TArtifact) *TModule {
	if mod == nil {
		return nil
	}

	for i := 0; i < len(a.Path); i++ {
		for j := 0; j < len(mod.Sub); j++ {
			if mod.Sub[j].Name == a.Path[i] {
				mod = &(mod.Sub[j])
				break
			}
			if j + 1 == len(mod.Sub) {
				return nil
			}
		}
	}

	return mod
}

// Attempt to get a module from the root module using a specified path
// Returns nil if the module was not found.
func getModule(a TArtifact) *TModule {
	return getModuleRelative(prog, a)
}

// Get a module ion the current path.
// Returns nil if the index is out of range.
func getModuleInPath(p int) *TModule {
	m := len(cart.Path)

	if p < 0 || p > m {
		return nil
	}

	return getModule( TArtifact{ cart.Path[:p] , "" } )
}

// Find an artifact from a name and the module to search
// Returns nil if the node is not found in the module
func getNode(mod *TModule, n string) *tparse.Node {

	for i := 0; i < len(mod.Artifacts); i++ {
		chk := getNames(mod.Artifacts[i])
		for j := 0; j < len(chk); j++ {
			if chk[j] == n {
				return &(mod.Artifacts[i])
			}
		}
	}

	return nil
}

func getDef(mod *TModule, n string) *TVariable {
	ret, prs := (*mod).Defs[n]
	if prs {
		return ret
	}
	return nil
}

// This is a horrible way to search through nodes with this structure.  O(n^3).
// This could (and should) be made better by using a dictionary like structure for sub-modules and artifacts.
// By sacrificing this type of tree it could probably get down to O(n^2) or even O(n) if you were good enough.
// Most probably, the following is not how it will be implemented in the final version of the compiler.
// If this wasn't a bootstrap/hoby project, I would probably fire myself for the following code.

// Yes, I am aware that the following code is bad.
// No, I don't care.

// The first variable it returns represents the block if one was found
// The second node represents the absolute path to the block
func searchNode(s TArtifact) (*tparse.Node, TArtifact) {

	// i-- because we are doing a reverse lookup
	for i := len(cart.Path); i >= 0; i-- { // O(n)
		tst := getModuleInPath(i) // O(n^2) (O(n^3) total here)
		tst = getModuleRelative(tst, s) // O(n^2) (O(n^3) total here)

		if tst == nil {
			continue
		}

		ret := getNode(tst, s.Name) // O(n^2) (O(n^3) total here)

		if ret != nil {
			pth := []string{}
			pth = append(pth, cart.Path[:i]...)
			pth = append(pth, s.Path...)
			return ret, TArtifact{ pth , s.Name }
		}
	} // Block total complexity 3*O(n^2) * O(n) = 3*O(n^3)

	return nil, tNull.T
}

func searchDef(s TArtifact) *TVariable {

	// i-- because of reverse lookup
	for i := len(cart.Path); i >= 0; i-- {
		tst := getModuleInPath(i)
		tst = getModuleRelative(tst, s)

		if tst == nil {
			continue
		}

		ret := getDef(tst, s.Name)

		if ret != nil {
			return ret
		}
	}
	return nil
}

// End block of complexity horror

// Type related stuff

// Checking type equality
// Assumes a is an unknown and b is also an unknown.
func equateTypePS(a, b TType, psa, psb int) bool {
	if len(a.T.Path) != len(b.T.Path) || len(a.Pre) - psa != len(b.Pre) - psb {
		return false
	}

	for i := 0; i < len(a.Pre) - psa; i++ {
		if a.Pre[psa + i] != b.Pre[psb + i] {
			return false
		}
	}

	for i := 0; i < len(a.T.Path);i++ {
		if a.T.Path[i] != b.T.Path[i] {
			return false
		}
	}

	if a.T.Name != b.T.Name || a.Post != b.Post {
		return false
	}

	return true
}

func equateTypePSB(a, b TType, ps int) bool {
	return equateTypePS(a, b, ps, ps)
}

// Checking type equality
// Assumes a is an unknown type and b is a known good type.
func equateTypePSO(a, b TType, ps int) bool {
	return equateTypePS(a, b, ps, 0)
}

func equateType(a, b TType) bool {
	return equateTypePS(a, b, 0, 0)
}

// Generate a TType from a 'type' node
func getType(t tparse.Node) TType {
	out := TType{}
	i := 0

	// Pre
	for ; i < len(t.Sub); i++ {
		if t.Sub[i].Data.Type == tparse.DEFWORD || t.Sub[i].Data.Type == tparse.KEYTYPE {
			break
		} else {
			out.Pre = append(out.Pre, t.Sub[i].Data.Data)
		}
	}

	// T
	for ; i < len(t.Sub); i++ {
		if t.Sub[i].Data.Type == tparse.KEYTYPE {
			out.T.Name = t.Sub[i].Data.Data
			i++
			break
		} else if t.Sub[i].Data.Type == tparse.DEFWORD {
			if i < len(t.Sub) - 1 {
				if t.Sub[i + 1].Data.Type == tparse.DEFWORD {
					out.T.Path = append(out.T.Path, t.Sub[i].Data.Data)
				} else {
					out.T.Name = t.Sub[i].Data.Data
					break
				}
			} else {
				out.T.Name = t.Sub[i].Data.Data
			}
		}
	}

	// Post
	if i < len(t.Sub) {
		if t.Sub[i].Data.Data == "`" {
			out.Post = "`"
		}
	}

	return out
}

func stripType(t TType, s int) TType {
	return TType{t.Pre[s:], t.T, t.Post}
}

func prependType(t TType, p string) TType {
	return TType{append(t.Pre, p), t.T, t.Post}
}

// Value generation

func getStringLiteral(v tparse.Node) []interface{} {
	str, err := strconv.Unquote(v.Data.Data)

	if err != nil {
		errOut(fmt.Sprintf("Failed to parse string literal %v", v.Data))
	}

	dat := []byte(str)
	out := []interface{}{}

	for i := 0; i < len(dat); i++ {
		out = append(out, dat[i])
	}

	return out
}

func getCharLiteral(v tparse.Node) byte {
	val, mb, _, err := strconv.UnquoteChar(v.Data.Data[1:], byte('\''))

	if err != nil || mb == true{
		errOut(fmt.Sprintf("Failed to parse character as single byte. %v", v.Data))
	}

	return byte(val)
}

func getIntLiteral(v tparse.Node) int {
	i, err := strconv.ParseInt(v.Data.Data, 0, 64)

	if err != nil {
		errOut(fmt.Sprintf("Failed to parse integer literal. %v", v.Data))
	}

	return int(i)
}

func getFloatLiteral(v tparse.Node) float64 {
	i, err := strconv.ParseFloat(v.Data.Data, 64)

	if err != nil {
		errOut(fmt.Sprintf("Failed to parse float literal. %v", v.Data))
	}

	return float64(i)
}

func getLiteralComposite(v tparse.Node) []interface{} {
	out := []interface{}{}

	for i := 0; i < len(v.Sub); i++ {
		if v.Sub[i].Data.Data[0] == '"' {
			out = append(out, getStringLiteral(v.Sub[i]))
		} else if v.Sub[i].Data.Data[0] == '\'' {
			out = append(out, getCharLiteral(v.Sub[i]))
		} else if v.Sub[i].Data.Data == "comp" {
			out = append(out, getLiteralComposite(v.Sub[i]))
		} else if v.Sub[i].Data.Data[0] == '0' {
			out = append(out, getIntLiteral(v.Sub[i]))
		} else {
			out = append(out, getFloatLiteral(v.Sub[i]))
		}
	}

	return out
}

func getBoolLiteral(v tparse.Node) bool {
	return v.Data.Data == "true"
}

func getLiteral(v tparse.Node, t TType) interface{} {
	if equateType(t, tFloat) {
		return getFloatLiteral(v)
	} else if equateType(t, tCharp) {
		return getCharLiteral(v)
	} else if equateType(t, tString) {
		return getStringLiteral(v)
	} else if equateType(t, tBool) {
		return getBoolLiteral(v)
	} else if equateType(t, tInt) {
		return getIntLiteral(v)
	}

	return getLiteralComposite(v)
}

func getLiteralType(v tparse.Node) TType {
	if v.Data.Data[0] == '"' {
		return tString
	} else if v.Data.Data[0] == '\'' {
		return tCharp
	} else if v.Data.Data == "comp" {
		return tStruct
	} else if v.Data.Data == "true" || v.Data.Data == "false" {
		return tBool
	} else if len(v.Data.Data) > 2 && v.Data.Data[0] == '0' && v.Data.Data[1] != '.' {
		return tInt
	} else {
		return tFloat
	}
}

// Convert Value to Struct from Array (cvsa)
// USE ONLY IN THE CASE OF tStruct!
func cvsa(sct TArtifact, dat []interface{}) VarMap {
	sv := searchDef(sct)
	
	old_c := cart
	cart = sct
	
	vars := sv.Data.([]TVariable)
	if len(vars) != len(dat) {
		return nil
	}

	out := make(VarMap)

	for i:=0;i<len(vars);i++ {
		tmp := TVariable{vars[i].Type, nil}
		if isStruct(vars[i].Type, 0) {
			tmp.Data = cvsa(vars[i].Type.T, dat[i].([]interface{}))
		} else {
			tmp.Data = dat[i]
		}
		out[vars[i].Data.(string)] = &tmp
	}

	cart = old_c

	return out
}

// Copy aray to aray (cata)
func cata(st TArtifact, dat []interface{}) []interface{} {
	out := []interface{}{}

	for i := 0; i < len(dat); i++ {
		switch v := dat[i].(type) {
		case []interface{}:
			out = append(out, cata(st, v))
		case VarMap:
			out = append(out, csts(st, v))
		default:
			out = append(out, convertValPS(TType{[]string{}, st, ""}, 0, v))
		}
	}

	return out
}

// Copy struct to struct
// Makes a deep copy of a struct.
func csts(st TArtifact, dat VarMap) VarMap {
	sv := searchDef(st)
	
	old_c := cart
	cart = st
	
	vars := sv.Data.([]TVariable)

	out := make(VarMap)

	for i := 0; i < len(vars); i++ {
		var dts interface{} = nil

		switch v := dat[vars[i].Data.(string)].Data.(type) {
		case []interface{}:
			dts = cata(vars[i].Type.T, v)
		case VarMap:
			dts = csts(vars[i].Type.T, v)
		default:
			dts = v
		}
		
		out[vars[i].Data.(string)] = &TVariable{vars[i].Type, dts}
	}

	cart = old_c

	return out
}

func convertValPS(to TType, sk int, dat interface{}) interface{} {
	if isPointer(to, sk) || equateTypePSO(to, tFile, sk) {
		return dat
	}

	var numcv float64
	switch v := dat.(type) {
	case []interface{}:
		if isArray(to, sk) {
			return cata(to.T, v)
		} else if isStruct(to, sk) {
			return cvsa(to.T, v)
		}
	case VarMap:
		return csts(to.T, v)
	case int:
		numcv = float64(v)
		goto NCV
	case byte:
		numcv = float64(v)
		goto NCV
	case float64:
		numcv = v
		goto NCV
	case bool:
		numcv = 0
		if v {
			numcv = 1
		}
		goto NCV
	}

	errOut(fmt.Sprintf("Unable to convert between two types.\nTO: %v\nSK: %d\nDT: %v", to, sk, dat))
	return nil

	NCV:
	if equateTypePSO(to, tInt, sk) {
		return int(numcv)
	} else if equateTypePSO(to, tFloat, sk) {
		return float64(numcv)
	} else if equateTypePSO(to, tByte, sk) || equateTypePSO(to, tCharp, sk) {
		return byte(numcv)
	} else if equateTypePSO(to, tBool, sk) {
		return numcv != 0
	}

	errOut(fmt.Sprintf("Unable to convert between two types.\nTO: %v\nSK: %d\nDT: %v", to, sk, dat))
	return nil
}

func convertVal(dat *TVariable, to TType) *TVariable {
	return &TVariable{to, convertValPS(to, 0, dat.Data)}
}

//#####################
//# Finding Artifacts #
//#####################

func resolveArtifactCall(a TArtifact, params []TVariable) TVariable {
	tres := tnslResolve(a)
	if tres == 0 {
		if len(params) > 0 {
			return tnslEval(params[0], a.Name)
		} else {
			errOut("Need at least one arg to call tnsl.io func")
		}
	}

	blk, pth := searchNode(a)

	if blk == nil {
		errOut(fmt.Sprintf("Invalid call to %v", a))
	}

	// Store and restore the path to the block
	ocrt := cart
	cart = pth
	out := evalBlock(*blk, params, false)
	cart = ocrt

	return out
}

func resolveStructCall(a TArtifact, method string, params []TVariable) TVariable {
	if len(a.Path) > 0 && a.Path[0] == "tnsl" {
		a.Path = append(a.Path, a.Name)
		a.Name = method
		tres := tnslResolve(a)

		if a.Name == "close" || a.Name == "read" {
			params = append(params, null)
		}

		if tres == 1 {
			if len(params) > 1 {
				return tnslFileEval(TVariable{tFile, *(params[0].Data.(*interface{}))}, params[1], a.Name)
			} else {
				errOut("Not enough args recieved to call tnsl.io.File method.")
			}
		} else {
			return null
		}
	}

	blk, pth := searchNode(a)

	if blk == nil {
		errOut(fmt.Sprintf("Could not find a method block for given type %v", a))
	}

	for i := 0; i < len(blk.Sub); i++ {
		if getBlockName(blk.Sub[i])[0] == method {
			ocrt := cart
			cart = pth
			out := evalBlock(blk.Sub[i], params, true)
			cart = ocrt
			return out
		}
	}

	errOut(fmt.Sprintf("Could not find method %s in type %v", method, a))
	return null
}

func resolveArtifact(a TArtifact, ctx *VarMap) *TVariable {
	val, prs := (*ctx)[a.Name]
	if !prs || len(a.Path) != 0 {
		// Try searching the modules for it
		val = searchDef(a)
	}
	return val
}

//#################
//# Runtime funcs #
//#################

// Value statement parsing

func isStruct(t TType, skp int) bool {
	ch := false

	ch = ch || isPointer(t, skp)
	ch = ch || isArray(t, skp)
	ch = ch || equateTypePSO(t, tFile, skp)
	ch = ch || equateTypePSO(t, tInt, skp)
	ch = ch || equateTypePSO(t, tByte, skp)
	ch = ch || equateTypePSO(t, tFloat, skp)
	ch = ch || equateTypePSO(t, tCharp, skp)
	ch = ch || equateTypePSO(t, tBool, skp)
	ch = ch || equateTypePSO(t, tNull, skp)

	return !ch
}

func isPointer(t TType, skp int) bool {

	if len(t.Pre) <= skp {
		return false
	}

	return t.Pre[skp] == "~"
}

func isArray(t TType, skp int) bool {
	if len(t.Pre) <= skp {
		return false
	}

	return t.Pre[skp] == "{}"
}

// Deals with call and index nodes
func evalCIN(v tparse.Node, ctx *VarMap, wk *TVariable) *TVariable {
	if v.Sub[0].Data.Data == "call" {
		if v.Data.Data == "append" && isArray(wk.Type, 0) {
			tmp := convertVal(evalValue(v.Sub[0].Sub[0], ctx), stripType(wk.Type, 1))
			i := len((*(wk.Data.(*interface{}))).([]interface{}))
			*(wk.Data.(*interface{})) = append((*(wk.Data.(*interface{}))).([]interface{}), tmp.Data)
			return &TVariable{stripType(wk.Type, 1), &((*(wk.Data.(*interface{}))).([]interface{})[i])}
		}

		args := []TVariable{}
		
		pth := TArtifact{[]string{}, v.Data.Data}
		if wk != nil {
			pth = wk.Type.T
			if wk.Data != nil {
				args = append(args, *wk)
			}
		}

		for i := 0; i < len(v.Sub[0].Sub); i++ {
			args = append(args, *evalValue(v.Sub[0].Sub[i], ctx))
		}

		var tmp TVariable

		if wk != nil && wk.Data != nil {
			tmp = resolveStructCall(pth, v.Data.Data, args)
		} else {
			tmp = resolveArtifactCall(pth, args)
		}
		
		wk = &TVariable{tmp.Type, &(tmp.Data)}

	} else {
		if wk == nil {
			tmp, prs := (*ctx)[v.Data.Data]
			if !prs {
				errOutNode("Unable to find variable", v)
			}
			wk = &TVariable{tmp.Type, &(tmp.Data)}
		} else {
			tmp, prs := (*(wk.Data.(*interface{}))).(VarMap)[v.Data.Data]
			if !prs {
				errOutNode("Unable to find struct variable (index)", v)
			}
			wk = &TVariable{tmp.Type, &(tmp.Data)}
		}
	}

	for i := 0; i < len(v.Sub); i++ {
		switch v.Sub[i].Data.Data {
		case "index":
			ind := convertVal(evalValue(v.Sub[i].Sub[0], ctx), tInt).Data.(int)
			wk.Data = &(((*(wk.Data.(*interface{}))).([]interface{}))[ind])
			wk.Type = stripType(wk.Type, 1)
		case "`":
			// De-reference
			wk.Data = (*(wk.Data.(*interface{})))
			wk.Type = stripType(wk.Type, 1)
		}
	}

	return wk
}

func evalDotChain(v tparse.Node, ctx *VarMap) *TVariable {
	out, prs := (*ctx)[v.Sub[0].Data.Data]
	wnd := &(v.Sub[0])

	if v.Sub[0].Data.Data == "self" && !prs {
		errOutNode("Use of 'self' keyword outside of method block.", v)
	} else if !prs {
		out = nil
	} else {
		if wnd.Data.Data != "self" {
			out = &TVariable{out.Type, &(out.Data)}
		}

		if len(v.Sub[0].Sub) > 0 {
			out = evalCIN(v.Sub[0], ctx, out)
		}

		v = v.Sub[1]
		if v.Data.Data == "." {
			wnd = &(v.Sub[0])
		} else {
			wnd = &v
		}
	}

	wrk := TArtifact{[]string{}, ""}

	for ;; {
		if out == nil {
			if wrk.Name != "" {
				wrk.Path = append(wrk.Path, wrk.Name)
			}
			wrk.Name = wnd.Data.Data

			tmp := searchDef(wrk)
			if tmp != nil {
				out = &TVariable{tmp.Type, &(tmp.Data)}
			}
		}

		if len(wnd.Sub) > 0 {
				if out == nil {
					out = evalCIN(*wnd, ctx, &TVariable{TType{[]string{}, wrk, ""}, nil})
				} else {
					if wnd.Sub[len(wnd.Sub) - 1].Data.Data == "++" || v.Sub[len(wnd.Sub) - 1].Data.Data == "--" {
						tctx := (*(out.Data.(*interface{}))).(VarMap)
						return setVal(v, &(tctx), nil)
					}
					out = evalCIN(*wnd, ctx, out)
				}
		} else if out != nil {
			tmp, prs := (*(out.Data.(*interface{}))).(VarMap)[wnd.Data.Data]
			if !prs {
				errOutNode("Unable to find struct variable (dot)", v)
			}
			out = &TVariable{tmp.Type, &(tmp.Data)}
		}

		if v.Data.Data == "." {
			v = v.Sub[1]
			if v.Data.Data == "." {
				wnd = &(v.Sub[0])
			} else {
				wnd = &v
			}
		} else {
			break
		}
	}

	return out
}

func setVal(v tparse.Node, ctx *VarMap, val *TVariable) *TVariable {
	var wrk *TVariable = nil

	if v.Data.Data == "." {
		wrk = evalDotChain(v, ctx)
		
		if wrk == nil {
			errOutNode("Unable to set a variable who's type is null. (Did you make a function call somewhere?)", v)
		}
		
		for ;v.Data.Data == "."; {
			v = v.Sub[1]
		}
	} else {
		tmp, prs := (*ctx)[v.Data.Data]

		if !prs {
			errOutCTX("Unable to set a variable due to the variable not existing.", ctx)
		}

		wrk = &TVariable{tmp.Type, &(tmp.Data)}

		if len(v.Sub) > 0 {
			wrk = evalCIN(v, ctx, nil)
		}
	}

	if len(v.Sub) > 0 {
		if v.Sub[len(v.Sub) - 1].Data.Data == "++" {
			val = &TVariable{tFloat, convertValPS(tFloat, 0, *(wrk.Data.(*interface{}))).(float64) + 1}
		} else if v.Sub[len(v.Sub) - 1].Data.Data == "--" {
			val = &TVariable{tFloat, convertValPS(tFloat, 0, *(wrk.Data.(*interface{}))).(float64) - 1}
		}
	}

	var set *interface{} = wrk.Data.(*interface{})

	(*set) = convertValPS((*wrk).Type, 0, val.Data)
	
	return wrk
}

// Parse a value node
func evalValue(v tparse.Node, ctx *VarMap) *TVariable {

	// STRUCT/ARRAY DEF
	if v.Data.Data == "comp" {
		out := []interface{}{}

		for i := 0; i < len(v.Sub); i++ {
			tmp := evalValue(v.Sub[i], ctx)
			out = append(out, (*tmp).Data)
		}

		return &TVariable{tStruct, out}
	}

	switch v.Data.Type {
	case tparse.LITERAL:
		if v.Data.Data == "self" {
			s, prs := (*ctx)["self"]
			if !prs {
				errOutNode("Use of 'self' keyword when not in a method.", v)
			}
			return &TVariable{s.Type, *(s.Data.(*interface{}))}
		}
		t := getLiteralType(v)
		return &TVariable{t, getLiteral(v, t)}
	case tparse.DEFWORD:
		if len(v.Sub) > 0 {
			if v.Sub[len(v.Sub) - 1].Data.Data == "++" || v.Sub[len(v.Sub) - 1].Data.Data == "--" {
				return setVal(v, ctx, nil)
			}
			ref := evalCIN(v, ctx, nil)
			if ref == nil {
				return &null
			}
			return &TVariable{ref.Type, *(ref.Data.(*interface{}))}
		}

		return resolveArtifact(TArtifact{[]string{}, v.Data.Data}, ctx)

	case tparse.AUGMENT:
		// Special cases
		switch v.Data.Data {
		case "=":
			return setVal(v.Sub[0], ctx, evalValue(v.Sub[1], ctx))
		case ".":
			ref := evalDotChain(v, ctx)
			if ref == nil {
				return &null
			}
			return &TVariable{ref.Type, *(ref.Data.(*interface{}))}
		}

		if len(v.Sub) == 1 {
			switch v.Data.Data {
			case "!":
				a := convertVal(evalValue(v.Sub[0], ctx), tBool)
				return &TVariable{tBool, !(a.Data.(bool))}
			case "len":
				a := evalValue(v.Sub[0], ctx)
				return &TVariable{tInt, len(a.Data.([]interface{}))}
			case "~":
				a := evalValue(v.Sub[0], ctx)
				typ := a.Type
				typ.Pre = append([]string{"~"}, typ.Pre...)
				return &TVariable{typ, &(a.Data)}
			case "-":
				a := convertVal(evalValue(v.Sub[0], ctx), tFloat)
				a.Data = -(a.Data.(float64))
				return a
			}
		}

		// General case setup
		
		a := convertVal(evalValue(v.Sub[0], ctx), tFloat)
		b := convertVal(evalValue(v.Sub[1], ctx), tFloat)
		var out TVariable
		out.Type = tFloat

		// General math and bool cases
		switch v.Data.Data {
		case "+":
			out.Data = a.Data.(float64) + b.Data.(float64)
		case "-":
			out.Data = a.Data.(float64) - b.Data.(float64)
		case "*":
			out.Data = a.Data.(float64) * b.Data.(float64)
		case "/":
			out.Data = a.Data.(float64) / b.Data.(float64)
		case "%":
			out.Type = tInt
			out.Data = int(a.Data.(float64)) % int(b.Data.(float64))
		case "&&":
			out.Type = tBool
			out.Data = a.Data.(float64) == 1 && b.Data.(float64) == 1
		case "||":
			out.Type = tBool
			out.Data = a.Data.(float64) == 1 || b.Data.(float64) == 1
		case "==":
			out.Type = tBool
			out.Data = a.Data == b.Data
		case "!==":
			out.Type = tBool
			out.Data = a.Data != b.Data
		case ">":
			out.Type = tBool
			out.Data = a.Data.(float64) > b.Data.(float64)
		case "<":
			out.Type = tBool
			out.Data = a.Data.(float64) < b.Data.(float64)
		case ">=":
			out.Type = tBool
			out.Data = a.Data.(float64) >= b.Data.(float64)
		case "<=":
			out.Type = tBool
			out.Data = a.Data.(float64) <= b.Data.(float64)
		}

		return &out
	}

	return &null
}

// Eval a definition
func evalDef(v tparse.Node, ctx *VarMap) {
	t := getType(v.Sub[0])
	
	for i := 0; i < len(v.Sub[1].Sub); i++ {
		if v.Sub[1].Sub[i].Data.Data == "=" {
			(*ctx)[v.Sub[1].Sub[i].Sub[0].Data.Data] = convertVal(evalValue(v.Sub[1].Sub[i].Sub[1], ctx), t)
		} else {
			(*ctx)[v.Sub[1].Sub[i].Data.Data] = &TVariable{t, nil}
		}
	}
}

// Eval a control flow
func evalCF(v tparse.Node, ctx *VarMap) (bool, TVariable, int) {

	loop := true
	ifout := true
	cond := tparse.Node{tparse.Token{tparse.LITERAL, "true", -1, -1}, []tparse.Node{}}
	var after *tparse.Node = nil

	if v.Sub[0].Data.Data == "bdef" {
		var before *tparse.Node = nil

		for i := 0; i < len(v.Sub[0].Sub); i++ {
			switch v.Sub[0].Sub[i].Data.Data {
			case "if", "else":
				loop = false
			case "()":
				before = &(v.Sub[0].Sub[i])
			case "[]":
				after = &(v.Sub[0].Sub[i])
			}
		}

		if before != nil {
			for i := 0; i < len(before.Sub); i++ {
				switch before.Sub[i].Data.Data {
				case "define":
					evalDef(before.Sub[i], ctx)
				case "value":
					val := *evalValue(before.Sub[i].Sub[0], ctx)
					if i == len(before.Sub) - 1 && equateType(val.Type, tBool) {
						cond = before.Sub[i].Sub[0]
						ifout = val.Data.(bool)
					}
				}
			}
		}
	}

	for ; (!loop && ifout) || evalValue(cond, ctx).Data.(bool) ; {
		for i := 0; i < len(v.Sub); i++ {
			switch v.Sub[i].Data.Data {
			case "define":
				evalDef(v.Sub[i], ctx)
			case "value":
				evalValue(v.Sub[i].Sub[0], ctx)
			case "block":
				ret, val, brk := evalCF(v.Sub[i], ctx)
				if ret {
					return ret, val, 0
				} else if brk < 0 {
					if brk < -1 {
						return false, null, brk + 1
					}
					goto CONCF
				} else if brk > 0 {
					return false, null, brk - 1
				} else if equateType(val.Type, tIF) {
					if val.Data.(bool) == true {
						i++

						for ;i < len(v.Sub) && getNames(v.Sub[i])[0] == "else"; i++ {}
						
						if i < len(v.Sub) {
							i--
						}
					}
				}
			case "return":
				if len(v.Sub[i].Sub) > 0 {
					return true, *evalValue(v.Sub[i].Sub[0], ctx), 0
				}
				return true, null, 0
			case "break":
				brk := 1
				if len(v.Sub[i].Sub) > 0 {
					brk = getIntLiteral(v.Sub[i].Sub[0])
				}
				if !loop {
					return false, null, brk
				}
				return false, null, brk - 1
			case "continue":
				cont := 1
				if len(v.Sub[i].Sub) > 0 {
					cont = getIntLiteral(v.Sub[i].Sub[0])
				}
				if !loop {
					return false, null, -cont
				} else if cont == 1 {
					goto CONCF
				}
				return false, null, 1 - cont
			}
		}

		CONCF:

		if after != nil {
			for i := 0; i < len(after.Sub); i++ {
				switch after.Sub[i].Data.Data {
				case "define":
					evalDef(after.Sub[i], ctx)
				case "value":
					val := *evalValue(after.Sub[i].Sub[0], ctx)
					if i == len(after.Sub) - 1 && equateType(val.Type, tBool) {
						cond = after.Sub[i].Sub[0]
					}
				}
			}
		}

		if !loop {
			break
		}
	}

	if !loop {
		return false, TVariable{tIF, ifout}, 0
	}

	return false, null, 0
}

func evalParams(pd tparse.Node, params *[]TVariable, ctx *VarMap, method bool) {
	if len(pd.Sub) == 0 {
		return
	}
	cvt := getType(pd.Sub[0])
	pi := 0
	
	if method {
		pi = 1
	}
	
	for i := 1; i < len(pd.Sub); i++ {
		if pd.Sub[i].Data.Type == 10 && pd.Sub[i].Data.Data == "type" {
			cvt = getType(pd.Sub[i])
		} else if pd.Sub[i].Data.Type == tparse.DEFWORD {
			(*ctx)[pd.Sub[i].Data.Data] = convertVal(&(*params)[pi], cvt)
			pi++
		}
	}
}

func evalBlock(b tparse.Node, params []TVariable, method bool) TVariable {
	ctx := make(VarMap)

	var rty TType = tNull

	if method {
		ctx["self"] = &(params[0])
	}

	if b.Sub[0].Data.Data == "bdef" {
		for i := 0; i < len(b.Sub[0].Sub); i++ {
			if b.Sub[0].Sub[i].Data.Data == "[]" {
				rty = getType(b.Sub[0].Sub[i])
			} else if b.Sub[0].Sub[i].Data.Data == "()" {
				evalParams(b.Sub[0].Sub[i], &params, &ctx, method)
			}
		}
	}

	for i := 0; i < len(b.Sub); i++ {
		switch b.Sub[i].Data.Data {
		case "define":
			evalDef(b.Sub[i], &ctx)
		case "value":
			evalValue(b.Sub[i].Sub[0], &ctx)
		case "block":
			ret, val, _ := evalCF(b.Sub[i], &ctx)
			if ret {
				return *convertVal(&val, rty)
			} else if equateType(val.Type, tIF) {
				if val.Data.(bool) == true {
					i++

					for ;i < len(b.Sub) && b.Sub[i].Data.Data == "block"; {
						if getNames(b.Sub[i])[0] == "else" {
							i++
						} else {
							break
						}
					}
					
					if i < len(b.Sub) {
						i--
					}
				}
			}
		case "return":
			return *convertVal(evalValue(b.Sub[i].Sub[0], &ctx), rty)
		}
	}

	return null
}

func EvalTNSL(root *TModule, args string) TVariable {
	prog = root
	cart = TArtifact { []string{}, "main" }

	sarg := strings.Split(args, " ")

	saif := []interface{}{}

	for i := 0; i < len(sarg); i++ {
		tmp := []interface{}{}
		dat := []byte(sarg[i])
		for j := 0; j < len(dat); j++ {
			tmp = append(tmp, dat[j])
		}

		saif = append(saif, tmp)
	}

	targ := TVariable {
		TType {
			[]string{"{}", "{}"},
			TArtifact { []string{}, "charp" },
			"" },
		saif }

	mainNode := getNode(prog, "main")

	//fmt.Println(mainNode)

	return evalBlock(*mainNode, []TVariable{targ}, false)
}