chore: move symbol table types and functions to their own module

internal/symbol-table/symbol-table.go

@@ -0,0 +1,85 @@
+package table
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type VariableKind int
+
+const (
+	STATIC VariableKind = iota
+	FIELD
+	ARG
+	VAR
+)
+
+type Variable struct {
+	Type       string
+	Kind       VariableKind
+	Count      int
+	IsDeclared bool
+	IsUsed     bool
+}
+
+func CountVariables(symbolTable *map[string]Variable, kind VariableKind) int {
+	count := -1
+
+	for _, variable := range *symbolTable {
+		if variable.Kind == kind {
+			count++
+		}
+	}
+
+	return count
+}
+
+func GetVariable(symbolTables []*map[string]Variable, name string) (Variable, bool) {
+	for _, table := range symbolTables {
+		for key, variable := range *table {
+			if key == name {
+				return variable, true
+			}
+		}
+	}
+
+	return Variable{}, false
+}
+
+func UseVariable(symbolTables []*map[string]Variable, name string) {
+	for _, table := range symbolTables {
+		for key, variable := range *table {
+			if key == name {
+				variable.IsUsed = true
+				(*table)[key] = variable
+				return
+			}
+		}
+	}
+}
+
+func WriteImplicitThis(output *strings.Builder, symbolTables []*map[string]Variable) error {
+	variable, found := GetVariable(symbolTables, "this")
+
+	if found {
+		tokenDefinition := "<implicitVariable> "
+		tokenDefinition += "name: this, "
+		tokenDefinition += "type: " + variable.Type + ", "
+		tokenDefinition += "kind: " + fmt.Sprint(variable.Kind) + ", "
+		tokenDefinition += "count: " + fmt.Sprint(variable.Count) + ", "
+		tokenDefinition += "declared: " + strconv.FormatBool(variable.IsDeclared) + ", "
+		tokenDefinition += "used: " + strconv.FormatBool(variable.IsUsed)
+		tokenDefinition += "</variable>\n"
+
+		if _, err := output.WriteString(tokenDefinition); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func AppendVariable(symbolTable *map[string]Variable, name string, variableType string, kind VariableKind) {
+	(*symbolTable)[name] = Variable{Type: variableType, Kind: kind, Count: CountVariables(symbolTable, kind) + 1, IsDeclared: true}
+}