error handling and transformation improvements

Added vscode config for easy debug including all modules.

memorybase/faulty.mdem

@@ -0,0 +1,25 @@
+
+
+
+- Another question? >
+    - Answer
+    - Answer
+    - Answer
+    - Answer
+    - Answer
+
+
+    oejcoewjic
+
+- Question? >
+    - Answer
+
+
+
+    fwefew
+
+    dwedew
+    dwe
+
+
+    dee

memorybase/hello.mdem

@@ -1,110 +1,42 @@
-
+- [cap_riga] 1 What is the capital of Latvia? >
-- [cap_riga] What is the capital of Latvia? >
     - Riga 
-
+- [cap_riga] 2 What is the capital of Latvia? >
-- [cap_riga] What is the capital of Latvia? >
     - Riga 
-
+- [cap_riga] 3 What is the capital of Latvia? >
-- [cap_riga] What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 4 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 5 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 6 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 7 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 8 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 9 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 10 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 11 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 12 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 13 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 14 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 15 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 16 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 17 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 18 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 19 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 20 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
+- [cap_riga] 21 What is the capital of Latvia? >
     - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-- [cap_riga] What is the capital of Latvia? >
-    - Riga 
-

src/.vscode/launch.json

@@ -0,0 +1,26 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${fileDirname}"
+        },
+        {
+            "name": "Debug with Build Flags",
+            "type": "go",
+            "request": "launch",
+            "mode": "debug",
+            "program": "${workspaceFolder}/mdemory-app-qt/main.go",
+           // "buildFlags": "-gcflags='all=-N -l'",
+            "args": [],
+            "env": {},
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

src/compiler/api/api.go

@@ -1,14 +1,13 @@
 package api
 
 import (
-
 	"github.com/jorenchik/mdemory/src/compiler/lexer"
 	"github.com/jorenchik/mdemory/src/compiler/parser"
 )
 
 func Compile(fileContents string) ([]parser.Question, error) {
 	tokens, err := lexer.TokenizeMdem([]rune(fileContents))
-	if err != nil {
+	if (err != nil) {
         return nil, err
 	}
     questions, err := parser.ParseQuestions(tokens)

src/compiler/comperror/comperror.go

@@ -0,0 +1,15 @@
+package comperror 
+
+import (
+    "fmt"
+)
+
+type PositionErr struct {
+	Message string
+	Row     int32
+	Column  int32
+}
+
+func (e PositionErr) Error() string {
+	return fmt.Sprintf("%d:%d - %s", e.Row, e.Column, e.Message)
+}

src/compiler/lexer/lexer.go

@@ -3,6 +3,8 @@ package lexer
 import (
 	"fmt"
 	"strings"
+
+	"github.com/jorenchik/mdemory/src/compiler/comperror"
 )
 
 var buffer            []rune
@@ -10,7 +12,8 @@ var	row              int32
 var	column              int32
 var	previousRow         int32
 var	previousColumn      int32
-var textStarted      bool
+var textStarted         bool  = false
+var identifierStarted   bool  = false
 
 type TokenType int
 const (
@@ -104,7 +107,6 @@ func TokenizeMdem(fileRunes []rune) ( []Token, error ) {
         return []Token{}, nil
     }
 
-
 	for i := 0; i < len(fileRunes); i++ {
 		c := fileRunes[i]
 
@@ -134,11 +136,21 @@ func TokenizeMdem(fileRunes []rune) ( []Token, error ) {
 			previousRow       = row
 			previousColumn    = column
 			textStarted       = false
+            identifierStarted = true
 		case ']':
+            if !identifierStarted {
+                return []Token{}, comperror.PositionErr{
+                    Message: "Cannot end identifier if it is not started",
+                    Row:     row,
+                    Column:  column,
+                } 
+
+            }
 			makeTokenWithTokenBuffer(IdentifierEnd, 1, Identifier)
 			previousRow       = row
 			previousColumn    = column
 			textStarted       = false
+            identifierStarted = false
 		case '#':
 			makeTokenWithTokenBuffer(SectionIdentifierStart, 1, TextFragment)
 			previousRow       = row
@@ -187,17 +199,17 @@ func TokenizeMdem(fileRunes []rune) ( []Token, error ) {
 
 func ToString (ttype *TokenType) string {
 	switch *ttype {
-        case TextFragment:           return "TextFragment"
+        case TextFragment:           return "text fragment"
-        case QuestionEnd:            return "QuestionEnd"               
+        case QuestionEnd:            return "question end symbol"
-        case ElementDashStart:       return "ElementDashStart"          
+        case ElementDashStart:       return "dash element start"
-        case ElementPlusStart:       return "ElementPlusStart"          
+        case ElementPlusStart:       return "plus element start"
-        case Identifier:             return "Identifier"                
+        case Identifier:             return "identifier"
-        case IdentifierStart:        return "IdentifierStart"            
+        case IdentifierStart:        return "start of identifier"
-        case IdentifierEnd:          return "IdentifierEnd"             
+        case IdentifierEnd:          return "end of identifier"
-        case SectionIdentifierStart: return "SectionIdentifierStart"             
+        case SectionIdentifierStart: return "identifier"
-        case SectionStart:           return "SectionStart"             
+        case SectionStart:           return "start of a section"
-        case SectionEnd:             return "SectionEnd"             
+        case SectionEnd:             return "end of a section"
-        case EOF:                    return "EndOfFile"             
+        case EOF:                    return "end of a file"
-        default:                     return "NOT_RECOGNIZED"
+        default:                     return "unrecognized token"
 	}
 }

src/compiler/parser/parser.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/jorenchik/mdemory/src/compiler/comperror"
 	"github.com/jorenchik/mdemory/src/compiler/lexer"
 )
 
@@ -67,16 +68,6 @@ type QuestionElement struct {
 
 var automata map[lexer.TokenType][]lexer.TokenType
 
-type CompilerErr struct {
-	message string
-	row     int32
-	column  int32
-}
-
-func (e CompilerErr) Error() string {
-	return fmt.Sprintf("%d:%d - %s", e.row, e.column, e.message)
-}
-
 func contains(s []lexer.TokenType, e lexer.TokenType) bool {
 	for _, a := range s {
 		if a == e {
@@ -140,20 +131,32 @@ func parserAutomata() map[lexer.TokenType][]lexer.TokenType {
 	return automata
 }
 
+func capitalize(str string) string {
+	if len(str) <= 0 {
+		return str
+	}
+	firstCapital := strings.ToUpper(str[0:1])
+    if len(str) == 1 {
+        return firstCapital
+    } else {
+        return firstCapital + str[1:]
+    }
+}
+
 func ValidateGrammar(tokens []lexer.Token) error {
 	automata = parserAutomata()
 	for i := 0; i < len(tokens)-1; i++ {
 		token := tokens[i]
 		nextToken := tokens[i+1]
 		if !contains(automata[token.TokenType], nextToken.TokenType) {
-			return CompilerErr{
+			return comperror.PositionErr{
-				message: fmt.Sprintf(
+				Message: fmt.Sprintf(
-					"Token %s cannot precede %s\n",
+					"%s cannot precede %s",
-					lexer.ToString(&token.TokenType),
+					capitalize(lexer.ToString(&token.TokenType)),
 					lexer.ToString(&nextToken.TokenType),
 				),
-				row:    token.Row,
+				Row:    token.Row,
-				column: token.Column,
+				Column: token.Column,
 			}
 		}
 	}
@@ -216,15 +219,15 @@ func ParseQuestions(tokens []lexer.Token) ([]Question, error) {
 						break
 					}
 					if offset == 5 && tokens[i+5].TokenType != lexer.QuestionEnd {
-                        return nil, CompilerErr{
+						return nil, comperror.PositionErr{
-                            message: "Cannot have an identifier here",
+							Message: "Cannot have an identifier here",
-                            row:     tokens[i].Row,
+							Row:     tokens[i].Row,
-                            column:  tokens[i].Column,
+							Column:  tokens[i].Column,
 						}
 					}
 				}
-                if (i + 2 >= len(tokens)) {
+				if i+2 >= len(tokens) {
-                    break;
+					break
 				}
 				questionElement := QuestionElement{}
 				if tokens[i].TokenType == lexer.ElementDashStart {
@@ -288,10 +291,10 @@ func ParseQuestions(tokens []lexer.Token) ([]Question, error) {
 			}
 			break
 		} else {
-			return nil, CompilerErr{
+			return nil, comperror.PositionErr{
-				message: "Unexpeced token: %s",
+				Message: "Unexpeced token",
-				row:     tokens[i].Row,
+				Row:     tokens[i].Row,
-				column:  tokens[i].Column,
+				Column:  tokens[i].Column,
 			}
 		}
 	}

src/mdemory-app-qt/main.go

@@ -1,23 +1,16 @@
 package main
 
-// iter: 1
-// [1] 2 3 4 5 6 7
-
-// 2
-// press 4
-//  1 2 3 [4] 5 6 7
-// 4 (page num) - 2
-
-
 import (
 	"fmt"
+	"math/rand"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 	"time"
-    "strconv"
-    "math/rand"
 
 	"github.com/jorenchik/mdemory/src/compiler/api"
+	"github.com/jorenchik/mdemory/src/compiler/comperror"
 	"github.com/jorenchik/mdemory/src/compiler/parser"
 	"github.com/therecipe/qt/core"
 	"github.com/therecipe/qt/widgets"
@@ -42,6 +35,12 @@ var questions         [] parser.Question
 var paginationButtons []*widgets.QToolButton
 var paginationLabel     *widgets.QLabel
 
+var errorBox            *widgets.QWidget
+var errorLabel          *widgets.QLabel 
+
+
+var multispacePattern   *regexp.Regexp = regexp.MustCompile(`\s\s+`)
+
 // var currentPage = 0
 var PER_PAGE = 10
 var pages []Page
@@ -156,13 +155,7 @@ func CreateMdem() *Mdem {
 }
 
 func CreateMdems(questions *[]parser.Question) {
-	if spacerInitialized {
     hMdemScroll.RemoveItem(mdemSpacer)
-	} else {
-		mdemSpacer = widgets.NewQSpacerItem(
-			0, 0, widgets.QSizePolicy__Maximum, widgets.QSizePolicy__Minimum,
-		)
-	}
 
 	for i := range mdems {
         if mdems[i].wMdem.IsVisible() {
@@ -179,6 +172,12 @@ func CreateMdems(questions *[]parser.Question) {
     }
 
 	// destroy widgets
+    transformAnswer := func(answer string) string {
+        answer = strings.ReplaceAll(answer, "\t", " ")
+        answer = strings.ReplaceAll(answer, "\n", " ")
+        answer = multispacePattern.ReplaceAllString(answer, ` `)
+        return answer 
+    }
 	for i := range *questions {
 		question := (*questions)[i]
 		switch question.(type) {
@@ -186,10 +185,10 @@ func CreateMdems(questions *[]parser.Question) {
 			mdems[i].wFrontText.SetText(
 				question.(parser.SingleAnswerQuestion).Question,
 			)
-            answer := strings.Trim(
+            answer := question.(parser.SingleAnswerQuestion).Answer 
-                question.(parser.SingleAnswerQuestion).Answer, " \t\n",
+            answer = transformAnswer(answer)
-            ) 
+            answer = fmt.Sprintf("- %s", answer)
-			mdems[i].backLabels[0].SetText(fmt.Sprintf("- %s", answer))
+			mdems[i].backLabels[0].SetText(answer)
             if mdems[i].wBack.IsVisible() {
                 mdems[i].wBack.Hide()
             }
@@ -200,11 +199,13 @@ func CreateMdems(questions *[]parser.Question) {
 				question.(parser.MultipleChoiceQuestion).Question,
 			)
 			for k := range choices {
-                answer := strings.Trim(choices[k].Answer, " \t\n") 
+                answer := choices[k].Answer
+                answer = transformAnswer(answer)
+                answer = fmt.Sprintf("- %s", answer)
 				if k < len(mdems[i].backLabels) {
 					mdems[i].backLabels[k].SetText(answer)
 				} else {
-					label := widgets.NewQLabel2(fmt.Sprintf("- %s", answer), nil, 0)
+					label := widgets.NewQLabel2(answer, nil, 0)
 					mdems[i].backLabels = append(
 						mdems[i].backLabels,
 						label,
@@ -219,15 +220,6 @@ func CreateMdems(questions *[]parser.Question) {
         }
 	}
 
-	if !spacerInitialized {
-		mdemSpacer = widgets.NewQSpacerItem(
-			40,
-			40,
-			widgets.QSizePolicy__Minimum,
-			widgets.QSizePolicy__Expanding,
-		)
-		spacerInitialized = true
-	}
 	hMdemScroll.AddItem(mdemSpacer)
 }
 
@@ -313,6 +305,9 @@ func OpenModelFile(
     if model.IsDir(index) {
         return
     }
+    if errorBox.IsVisible() {
+        errorBox.Hide()
+    }
     filePath := model.FilePath(index)
     fileContents, err := os.ReadFile(filePath)
     if err != nil {
@@ -329,13 +324,25 @@ func OpenModelFile(
     start := time.Now().UnixMicro()
     questions, err = api.Compile(string(fileContents))
     if err != nil {
-        widgets.QMessageBox_Critical(
+        var errText string
-            nil,
+        switch err.(type) {
-            "Compilation error",
+            case comperror.PositionErr:
-            err.Error(),
+                errText = fmt.Sprintf(
-            widgets.QMessageBox__Ok,
+                    "%s on line %d, column %d",
-            widgets.QMessageBox__Ok,
+                    err.(comperror.PositionErr).Message,
+                    err.(comperror.PositionErr).Row,
+                    err.(comperror.PositionErr).Column,
                 )
+            default:
+                errText = err.Error()
+        }
+        errorLabel.SetText(errText)
+        errorBox.Show()
+        for i := range(mdems) {
+            if mdems[i].wMdem.IsVisible() {
+                mdems[i].wMdem.Hide()
+            }
+        }
         return
     }
     duration := float32(time.Now().UnixMicro()-start) / 1000
@@ -420,6 +427,24 @@ func main() {
 	mdemScroll.SetWidgetResizable(true)
 	mdemContainer.SetLayout(hMdemScroll)
 
+    errorBox = widgets.NewQWidget(nil, 0)
+    hErrorBox := widgets.NewQHBoxLayout2(nil)
+    errorBox.SetLayout(hErrorBox)
+    errorLabel = widgets.NewQLabel(nil, 0)
+    errorLabel.SetText("Error")
+    errorBox.Layout().AddWidget(errorLabel)
+    hErrorBox.AddStretch(1)
+    hMdemScroll.AddWidget(errorBox, 0, 0)
+    errorBox.SetObjectName("error")
+    errorBox.SetStyleSheet(`
+        QWidget#error {
+            border: 1px solid #dc143c;
+            background-color: white;
+            padding: 10px 0px;
+        }
+    `)
+    errorBox.Hide()
+
 	for i := 0; i < 40; i++ {
         mdem := CreateMdem()
 		mdems = append(
@@ -428,6 +453,13 @@ func main() {
 		)
         hMdemScroll.AddWidget(mdem.wMdem, 0, 0)
 	}
+    mdemSpacer = widgets.NewQSpacerItem(
+        40,
+        40,
+        widgets.QSizePolicy__Minimum,
+        widgets.QSizePolicy__Expanding,
+    )
+    hMdemScroll.AddItem(mdemSpacer)
 
 	// CreateMdems
 	rightLayout.AddWidget(mdemScroll, 1, 0)