From b6559505169948404d44a1fc58ceba84f88e4ee5 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <admin@akyoto.dev>
Date: Thu, 20 Feb 2025 14:12:25 +0100
Subject: [PATCH] Simplified ast package

---
 src/ast/AST.go                                | 56 +++++++++++++++++++
 src/ast/Assert.go                             | 10 ----
 src/ast/Assign.go                             | 10 ----
 src/ast/Call.go                               |  8 ---
 src/ast/Count.go                              |  4 ++
 src/ast/Define.go                             | 10 ----
 src/ast/For.go                                |  9 ---
 src/ast/If.go                                 | 12 ----
 src/ast/Loop.go                               |  6 --
 src/ast/Parse.go                              | 25 ++-------
 src/ast/Return.go                             | 10 ----
 src/ast/Switch.go                             | 16 ------
 src/ast/block.go                              | 26 +++++++++
 ...{EachInstruction.go => eachInstruction.go} | 14 ++---
 src/ast/helpers.go                            | 21 +++++++
 src/ast/{parseSwitch.go => parseCases.go}     | 11 ++--
 src/ast/{parseNode.go => parseInstruction.go} | 19 ++++---
 src/ast/parseKeyword.go                       | 46 +++++----------
 src/core/CompileTokens.go                     |  6 +-
 19 files changed, 151 insertions(+), 168 deletions(-)
 delete mode 100644 src/ast/Assert.go
 delete mode 100644 src/ast/Assign.go
 delete mode 100644 src/ast/Call.go
 delete mode 100644 src/ast/Define.go
 delete mode 100644 src/ast/For.go
 delete mode 100644 src/ast/If.go
 delete mode 100644 src/ast/Loop.go
 delete mode 100644 src/ast/Return.go
 delete mode 100644 src/ast/Switch.go
 create mode 100644 src/ast/block.go
 rename src/ast/{EachInstruction.go => eachInstruction.go} (69%)
 create mode 100644 src/ast/helpers.go
 rename src/ast/{parseSwitch.go => parseCases.go} (60%)
 rename src/ast/{parseNode.go => parseInstruction.go} (59%)

diff --git a/src/ast/AST.go b/src/ast/AST.go
index 8dcaa24..99f1ed1 100644
--- a/src/ast/AST.go
+++ b/src/ast/AST.go
@@ -1,7 +1,63 @@
 package ast
 
+import "git.akyoto.dev/cli/q/src/expression"
+
 // Node is an interface used for all types of AST nodes.
 type Node any
 
 // AST is an abstract syntax tree which is simply a list of nodes.
 type AST []Node
+
+// Assert is a condition that must be true, otherwise the program stops.
+type Assert struct {
+	Condition *expression.Expression
+}
+
+// Assign is an assignment to an existing variable or memory location.
+type Assign struct {
+	Expression *expression.Expression
+}
+
+// Call is a function call.
+type Call struct {
+	Expression *expression.Expression
+}
+
+// Case is a case inside a switch.
+type Case struct {
+	Condition *expression.Expression
+	Body      AST
+}
+
+// Define is a variable definition.
+type Define struct {
+	Expression *expression.Expression
+}
+
+// For is a loop with a defined iteration limit.
+type For struct {
+	Head *expression.Expression
+	Body AST
+}
+
+// If is a conditional branch.
+type If struct {
+	Condition *expression.Expression
+	Body      AST
+	Else      AST
+}
+
+// Loop is an infinite loop.
+type Loop struct {
+	Body AST
+}
+
+// Return is a return statement.
+type Return struct {
+	Values []*expression.Expression
+}
+
+// Switch is a conditional branch with multiple cases.
+type Switch struct {
+	Cases []Case
+}
diff --git a/src/ast/Assert.go b/src/ast/Assert.go
deleted file mode 100644
index 6da47fb..0000000
--- a/src/ast/Assert.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// Assert represents a condition that must be true, otherwise the program stops.
-type Assert struct {
-	Condition *expression.Expression
-}
diff --git a/src/ast/Assign.go b/src/ast/Assign.go
deleted file mode 100644
index 8bdbe99..0000000
--- a/src/ast/Assign.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// Assign represents an assignment to an existing variable or memory location.
-type Assign struct {
-	Expression *expression.Expression
-}
diff --git a/src/ast/Call.go b/src/ast/Call.go
deleted file mode 100644
index 8aa683e..0000000
--- a/src/ast/Call.go
+++ /dev/null
@@ -1,8 +0,0 @@
-package ast
-
-import "git.akyoto.dev/cli/q/src/expression"
-
-// Call represents a function call.
-type Call struct {
-	Expression *expression.Expression
-}
diff --git a/src/ast/Count.go b/src/ast/Count.go
index 2c9f1f7..83e7f69 100644
--- a/src/ast/Count.go
+++ b/src/ast/Count.go
@@ -25,6 +25,10 @@ func Count(body AST, buffer []byte, kind token.Kind, name string) uint8 {
 			count += Count(node.Body, buffer, kind, name)
 			count += Count(node.Else, buffer, kind, name)
 
+		case *For:
+			count += node.Head.Count(buffer, kind, name)
+			count += Count(node.Body, buffer, kind, name)
+
 		case *Loop:
 			count += Count(node.Body, buffer, kind, name)
 
diff --git a/src/ast/Define.go b/src/ast/Define.go
deleted file mode 100644
index 0b8030c..0000000
--- a/src/ast/Define.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// Define represents a variable definition.
-type Define struct {
-	Expression *expression.Expression
-}
diff --git a/src/ast/For.go b/src/ast/For.go
deleted file mode 100644
index 32a080b..0000000
--- a/src/ast/For.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package ast
-
-import "git.akyoto.dev/cli/q/src/expression"
-
-// For is a loop with a defined iteration limit.
-type For struct {
-	Head *expression.Expression
-	Body AST
-}
diff --git a/src/ast/If.go b/src/ast/If.go
deleted file mode 100644
index 079640d..0000000
--- a/src/ast/If.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// If represents an if statement.
-type If struct {
-	Condition *expression.Expression
-	Body      AST
-	Else      AST
-}
diff --git a/src/ast/Loop.go b/src/ast/Loop.go
deleted file mode 100644
index 8bf3fac..0000000
--- a/src/ast/Loop.go
+++ /dev/null
@@ -1,6 +0,0 @@
-package ast
-
-// Loop is a block of infinitely repeating instructions.
-type Loop struct {
-	Body AST
-}
diff --git a/src/ast/Parse.go b/src/ast/Parse.go
index 8b9083e..84c9972 100644
--- a/src/ast/Parse.go
+++ b/src/ast/Parse.go
@@ -1,18 +1,18 @@
 package ast
 
 import (
-	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/fs"
 	"git.akyoto.dev/cli/q/src/token"
 )
 
 // Parse generates an AST from a list of tokens.
-func Parse(tokens []token.Token, source []byte) (AST, error) {
+func Parse(tokens []token.Token, file *fs.File) (AST, error) {
 	nodes := make(AST, 0, len(tokens)/64)
 
-	err := EachInstruction(tokens, func(instruction token.List) error {
-		node, err := parseNode(instruction, source, nodes)
+	err := eachInstruction(tokens, func(instruction token.List) error {
+		node, err := parseInstruction(instruction, file, nodes)
 
-		if err == nil && node != nil {
+		if node != nil {
 			nodes = append(nodes, node)
 		}
 
@@ -21,18 +21,3 @@ func Parse(tokens []token.Token, source []byte) (AST, error) {
 
 	return nodes, err
 }
-
-// IsAssignment returns true if the expression is an assignment.
-func IsAssignment(expr *expression.Expression) bool {
-	return expr.Token.IsAssignment()
-}
-
-// IsFunctionCall returns true if the expression is a function call.
-func IsFunctionCall(expr *expression.Expression) bool {
-	return expr.Token.Kind == token.Call
-}
-
-// IsVariableDefinition returns true if the expression is a variable definition.
-func IsVariableDefinition(expr *expression.Expression) bool {
-	return expr.Token.Kind == token.Define
-}
diff --git a/src/ast/Return.go b/src/ast/Return.go
deleted file mode 100644
index 8815638..0000000
--- a/src/ast/Return.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// Return represents a return statement.
-type Return struct {
-	Values []*expression.Expression
-}
diff --git a/src/ast/Switch.go b/src/ast/Switch.go
deleted file mode 100644
index a5fc6a0..0000000
--- a/src/ast/Switch.go
+++ /dev/null
@@ -1,16 +0,0 @@
-package ast
-
-import (
-	"git.akyoto.dev/cli/q/src/expression"
-)
-
-// Switch represents a switch statement.
-type Switch struct {
-	Cases []Case
-}
-
-// Case represents a case inside a switch.
-type Case struct {
-	Condition *expression.Expression
-	Body      AST
-}
diff --git a/src/ast/block.go b/src/ast/block.go
new file mode 100644
index 0000000..da58e2a
--- /dev/null
+++ b/src/ast/block.go
@@ -0,0 +1,26 @@
+package ast
+
+import (
+	"git.akyoto.dev/cli/q/src/errors"
+	"git.akyoto.dev/cli/q/src/fs"
+	"git.akyoto.dev/cli/q/src/token"
+)
+
+// block retrieves the start and end position of a block.
+func block(tokens token.List, file *fs.File) (blockStart int, blockEnd int, body AST, err error) {
+	blockStart = tokens.IndexKind(token.BlockStart)
+	blockEnd = tokens.LastIndexKind(token.BlockEnd)
+
+	if blockStart == -1 {
+		err = errors.New(errors.MissingBlockStart, file, tokens[0].End())
+		return
+	}
+
+	if blockEnd == -1 {
+		err = errors.New(errors.MissingBlockEnd, file, tokens[len(tokens)-1].End())
+		return
+	}
+
+	body, err = Parse(tokens[blockStart+1:blockEnd], file)
+	return
+}
diff --git a/src/ast/EachInstruction.go b/src/ast/eachInstruction.go
similarity index 69%
rename from src/ast/EachInstruction.go
rename to src/ast/eachInstruction.go
index b1a354f..ceb653f 100644
--- a/src/ast/EachInstruction.go
+++ b/src/ast/eachInstruction.go
@@ -2,13 +2,13 @@ package ast
 
 import "git.akyoto.dev/cli/q/src/token"
 
-// EachInstruction calls the function on each instruction.
-func EachInstruction(body token.List, call func(token.List) error) error {
+// eachInstruction calls the function on each AST node.
+func eachInstruction(tokens token.List, call func(token.List) error) error {
 	start := 0
 	groupLevel := 0
 	blockLevel := 0
 
-	for i, t := range body {
+	for i, t := range tokens {
 		if start == i && t.Kind == token.NewLine {
 			start = i + 1
 			continue
@@ -20,7 +20,7 @@ func EachInstruction(body token.List, call func(token.List) error) error {
 				continue
 			}
 
-			err := call(body[start:i])
+			err := call(tokens[start:i])
 
 			if err != nil {
 				return err
@@ -44,7 +44,7 @@ func EachInstruction(body token.List, call func(token.List) error) error {
 				continue
 			}
 
-			err := call(body[start : i+1])
+			err := call(tokens[start : i+1])
 
 			if err != nil {
 				return err
@@ -54,8 +54,8 @@ func EachInstruction(body token.List, call func(token.List) error) error {
 		}
 	}
 
-	if start != len(body) {
-		return call(body[start:])
+	if start != len(tokens) {
+		return call(tokens[start:])
 	}
 
 	return nil
diff --git a/src/ast/helpers.go b/src/ast/helpers.go
new file mode 100644
index 0000000..ffb2bf5
--- /dev/null
+++ b/src/ast/helpers.go
@@ -0,0 +1,21 @@
+package ast
+
+import (
+	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/token"
+)
+
+// IsAssignment returns true if the expression is an assignment.
+func IsAssignment(expr *expression.Expression) bool {
+	return expr.Token.IsAssignment()
+}
+
+// IsFunctionCall returns true if the expression is a function call.
+func IsFunctionCall(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Call
+}
+
+// IsVariableDefinition returns true if the expression is a variable definition.
+func IsVariableDefinition(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Define
+}
diff --git a/src/ast/parseSwitch.go b/src/ast/parseCases.go
similarity index 60%
rename from src/ast/parseSwitch.go
rename to src/ast/parseCases.go
index 65eb712..da6e561 100644
--- a/src/ast/parseSwitch.go
+++ b/src/ast/parseCases.go
@@ -2,15 +2,16 @@ package ast
 
 import (
 	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/fs"
 	"git.akyoto.dev/cli/q/src/token"
 )
 
-// parseSwitch generates the cases inside a switch statement.
-func parseSwitch(tokens token.List, source []byte) ([]Case, error) {
+// parseCases generates the cases inside a switch statement.
+func parseCases(tokens token.List, file *fs.File) ([]Case, error) {
 	var cases []Case
 
-	err := EachInstruction(tokens, func(caseTokens token.List) error {
-		blockStart, _, body, err := block(caseTokens, source)
+	err := eachInstruction(tokens, func(caseTokens token.List) error {
+		blockStart, _, body, err := block(caseTokens, file)
 
 		if err != nil {
 			return err
@@ -19,7 +20,7 @@ func parseSwitch(tokens token.List, source []byte) ([]Case, error) {
 		conditionTokens := caseTokens[:blockStart]
 		var condition *expression.Expression
 
-		if len(conditionTokens) == 1 && conditionTokens[0].Kind == token.Identifier && conditionTokens[0].Text(source) == "_" {
+		if len(conditionTokens) == 1 && conditionTokens[0].Kind == token.Identifier && conditionTokens[0].Text(file.Bytes) == "_" {
 			condition = nil
 		} else {
 			condition = expression.Parse(conditionTokens)
diff --git a/src/ast/parseNode.go b/src/ast/parseInstruction.go
similarity index 59%
rename from src/ast/parseNode.go
rename to src/ast/parseInstruction.go
index 919566e..c14db17 100644
--- a/src/ast/parseNode.go
+++ b/src/ast/parseInstruction.go
@@ -3,13 +3,14 @@ package ast
 import (
 	"git.akyoto.dev/cli/q/src/errors"
 	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/fs"
 	"git.akyoto.dev/cli/q/src/token"
 )
 
-// parseNode generates an AST node from an instruction.
-func parseNode(tokens token.List, source []byte, nodes AST) (Node, error) {
+// parseInstruction generates an AST node from an instruction.
+func parseInstruction(tokens token.List, file *fs.File, nodes AST) (Node, error) {
 	if tokens[0].IsKeyword() {
-		return parseKeyword(tokens, source, nodes)
+		return parseKeyword(tokens, file, nodes)
 	}
 
 	expr := expression.Parse(tokens)
@@ -19,24 +20,24 @@ func parseNode(tokens token.List, source []byte, nodes AST) (Node, error) {
 	}
 
 	switch {
+	case IsFunctionCall(expr):
+		return &Call{Expression: expr}, nil
+
 	case IsVariableDefinition(expr):
 		if len(expr.Children) < 2 {
-			return nil, errors.New(errors.MissingOperand, nil, expr.Token.End())
+			return nil, errors.New(errors.MissingOperand, file, expr.Token.End())
 		}
 
 		return &Define{Expression: expr}, nil
 
 	case IsAssignment(expr):
 		if len(expr.Children) < 2 {
-			return nil, errors.New(errors.MissingOperand, nil, expr.Token.End())
+			return nil, errors.New(errors.MissingOperand, file, expr.Token.End())
 		}
 
 		return &Assign{Expression: expr}, nil
 
-	case IsFunctionCall(expr):
-		return &Call{Expression: expr}, nil
-
 	default:
-		return nil, errors.New(&errors.InvalidInstruction{Instruction: tokens.Text(source)}, nil, tokens[0].Position)
+		return nil, errors.New(&errors.InvalidInstruction{Instruction: tokens.Text(file.Bytes)}, file, tokens[0].Position)
 	}
 }
diff --git a/src/ast/parseKeyword.go b/src/ast/parseKeyword.go
index a0a4d45..c012e38 100644
--- a/src/ast/parseKeyword.go
+++ b/src/ast/parseKeyword.go
@@ -3,44 +3,45 @@ package ast
 import (
 	"git.akyoto.dev/cli/q/src/errors"
 	"git.akyoto.dev/cli/q/src/expression"
+	"git.akyoto.dev/cli/q/src/fs"
 	"git.akyoto.dev/cli/q/src/token"
 )
 
 // parseKeyword generates a keyword node from an instruction.
-func parseKeyword(tokens token.List, source []byte, nodes AST) (Node, error) {
+func parseKeyword(tokens token.List, file *fs.File, nodes AST) (Node, error) {
 	switch tokens[0].Kind {
 	case token.Assert:
 		if len(tokens) == 1 {
-			return nil, errors.New(errors.MissingExpression, nil, tokens[0].End())
+			return nil, errors.New(errors.MissingExpression, file, tokens[0].End())
 		}
 
 		condition := expression.Parse(tokens[1:])
 		return &Assert{Condition: condition}, nil
 
 	case token.If:
-		blockStart, _, body, err := block(tokens, source)
+		blockStart, _, body, err := block(tokens, file)
 		condition := expression.Parse(tokens[1:blockStart])
 		return &If{Condition: condition, Body: body}, err
 
 	case token.Else:
-		_, _, body, err := block(tokens, source)
+		_, _, body, err := block(tokens, file)
 
 		if len(nodes) == 0 {
-			return nil, errors.New(errors.ExpectedIfBeforeElse, nil, tokens[0].Position)
+			return nil, errors.New(errors.ExpectedIfBeforeElse, file, tokens[0].Position)
 		}
 
 		last := nodes[len(nodes)-1]
 		ifNode, exists := last.(*If)
 
 		if !exists {
-			return nil, errors.New(errors.ExpectedIfBeforeElse, nil, tokens[0].Position)
+			return nil, errors.New(errors.ExpectedIfBeforeElse, file, tokens[0].Position)
 		}
 
 		ifNode.Else = body
 		return nil, err
 
 	case token.For:
-		blockStart, _, body, err := block(tokens, source)
+		blockStart, _, body, err := block(tokens, file)
 		head := tokens[1:blockStart]
 
 		loop := &For{
@@ -51,7 +52,7 @@ func parseKeyword(tokens token.List, source []byte, nodes AST) (Node, error) {
 		return loop, err
 
 	case token.Loop:
-		_, _, body, err := block(tokens, source)
+		_, _, body, err := block(tokens, file)
 		return &Loop{Body: body}, err
 
 	case token.Return:
@@ -67,42 +68,23 @@ func parseKeyword(tokens token.List, source []byte, nodes AST) (Node, error) {
 		blockEnd := tokens.LastIndexKind(token.BlockEnd)
 
 		if blockStart == -1 {
-			return nil, errors.New(errors.MissingBlockStart, nil, tokens[0].End())
+			return nil, errors.New(errors.MissingBlockStart, file, tokens[0].End())
 		}
 
 		if blockEnd == -1 {
-			return nil, errors.New(errors.MissingBlockEnd, nil, tokens[len(tokens)-1].End())
+			return nil, errors.New(errors.MissingBlockEnd, file, tokens[len(tokens)-1].End())
 		}
 
 		body := tokens[blockStart+1 : blockEnd]
 
 		if len(body) == 0 {
-			return nil, errors.New(errors.EmptySwitch, nil, tokens[0].Position)
+			return nil, errors.New(errors.EmptySwitch, file, tokens[0].Position)
 		}
 
-		cases, err := parseSwitch(body, source)
+		cases, err := parseCases(body, file)
 		return &Switch{Cases: cases}, err
 
 	default:
-		return nil, errors.New(&errors.KeywordNotImplemented{Keyword: tokens[0].Text(source)}, nil, tokens[0].Position)
+		return nil, errors.New(&errors.KeywordNotImplemented{Keyword: tokens[0].Text(file.Bytes)}, file, tokens[0].Position)
 	}
 }
-
-// block retrieves the start and end position of a block.
-func block(tokens token.List, source []byte) (blockStart int, blockEnd int, body AST, err error) {
-	blockStart = tokens.IndexKind(token.BlockStart)
-	blockEnd = tokens.LastIndexKind(token.BlockEnd)
-
-	if blockStart == -1 {
-		err = errors.New(errors.MissingBlockStart, nil, tokens[0].End())
-		return
-	}
-
-	if blockEnd == -1 {
-		err = errors.New(errors.MissingBlockEnd, nil, tokens[len(tokens)-1].End())
-		return
-	}
-
-	body, err = Parse(tokens[blockStart+1:blockEnd], source)
-	return
-}
diff --git a/src/core/CompileTokens.go b/src/core/CompileTokens.go
index 06bff0f..2aa390c 100644
--- a/src/core/CompileTokens.go
+++ b/src/core/CompileTokens.go
@@ -2,18 +2,16 @@ package core
 
 import (
 	"git.akyoto.dev/cli/q/src/ast"
-	"git.akyoto.dev/cli/q/src/errors"
 	"git.akyoto.dev/cli/q/src/token"
 )
 
 // CompileTokens compiles a token list.
 func (f *Function) CompileTokens(tokens []token.Token) error {
-	body, err := ast.Parse(tokens, f.File.Bytes)
+	tree, err := ast.Parse(tokens, f.File)
 
 	if err != nil {
-		err.(*errors.Error).File = f.File
 		return err
 	}
 
-	return f.CompileAST(body)
+	return f.CompileAST(tree)
 }