cleanup global state, fix .gitattributes

.gitattributes

@@ -1 +1,2 @@
 *.go text eol=lf
+*.peg text eol=lf

Makefile

@@ -80,7 +80,7 @@ $(EXAMPLES_DIR)/calculator/calculator.go: $(EXAMPLES_DIR)/calculator/calculator.
 	$(BINDIR)/pigeon $< > $@
 
 $(EXAMPLES_DIR)/indentation/indentation.go: $(EXAMPLES_DIR)/indentation/indentation.peg $(BINDIR)/pigeon
-	$(BINDIR)/pigeon $< | goimports > $@
+	$(BINDIR)/pigeon $< > $@
 
 $(TEST_DIR)/andnot/andnot.go: $(TEST_DIR)/andnot/andnot.peg $(BINDIR)/pigeon
 	$(BINDIR)/pigeon $< > $@
@@ -122,7 +122,7 @@ $(TEST_DIR)/alternate_entrypoint/altentry.go: $(TEST_DIR)/alternate_entrypoint/a
 	$(BINDIR)/pigeon -optimize-grammar -alternate-entrypoints Entry2,Entry3,C $< > $@
 
 $(TEST_DIR)/state/state.go: $(TEST_DIR)/state/state.peg $(BINDIR)/pigeon
-	$(BINDIR)/pigeon $< | goimports > $@
+	$(BINDIR)/pigeon $< > $@
 
 lint:
 	golint ./...

bootstrap/cmd/bootstrap-pigeon/bootstrap_pigeon.go

@@ -2788,14 +2788,12 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -3151,11 +3149,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 		defer p.out(p.in("parseChoiceExpr"))
 	}
 
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

builder/generated_static_code.go

@@ -636,16 +636,14 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	// ==template== {{ if not .Optimize }}
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
 	// {{ end }} ==template==
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1045,11 +1043,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 	}
 
 	// {{ end }} ==template==
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

builder/static_code.go

@@ -652,16 +652,14 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	// ==template== {{ if not .Optimize }}
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
 	// {{ end }} ==template==
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1061,11 +1059,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 	}
 
 	// {{ end }} ==template==
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

doc.go

@@ -309,7 +309,7 @@ parser will return. E.g.:
 	}
 
 The current type is a struct that provides four useful fields that can be
-accessed in action and predicate code blocks: "pos", "text", "store" and "globalStore".
+accessed in action and predicate code blocks: "pos", "text", "state" and "globalStore".
 
 The "pos" field indicates the current position of the parser in the source
 input. It is itself a struct with three fields: "line", "col" and "offset".
@@ -319,13 +319,12 @@ runes from the start of the line, and offset is a 0-based byte offset.
 The "text" field is the slice of bytes of the current match. It is empty
 in a predicate code block.
 
-The "store" field is a global store with backtrack support of type "map[string]interface{}",
+The "state" field is a global store with backtrack support of type "map[string]interface{}",
 which allows to store arbitrary values, which are available in action and
 predicate code blocks for read as well as write access.
 It is important to notice, that the global store is dependent from
 the backtrack mechanism of PEG and and it is set back to its old state
 during backtrack.
-Changes of "store" field in predicate expressions is not keeped.
 
 The "globalStore" field is a global store of type "map[string]interface{}",
 which allows to store arbitrary values, which are available in action and

examples/calculator/calculator.go

@@ -1066,14 +1066,12 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1429,11 +1427,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 		defer p.out(p.in("parseChoiceExpr"))
 	}
 
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

examples/indentation/indentation.go

@@ -1347,14 +1347,12 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1705,11 +1703,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 		defer p.out(p.in("parseChoiceExpr"))
 	}
 
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

examples/indentation/indentation_ast.go

@@ -31,12 +31,12 @@ func main() {
 
 var lvalues = make(map[string]int)
 
-// element of statements
-type Executor interface {
+// Statement is the smallest standalone element 
+type Statement interface {
 	exec() error
 }
 
-// ProgramNode
+// ProgramNode is a root node
 type ProgramNode struct {
 	statements StatementsNode
 	ret        ReturnNode
@@ -53,17 +53,17 @@ func (n ProgramNode) exec() (int, error) {
 	return n.ret.exec()
 }
 
-// StatementsNode
+// StatementsNode is a list of statement
 type StatementsNode struct {
-	statements []Executor
+	statements []Statement
 }
 
 func newStatementsNode(stmts interface{}) (StatementsNode, error) {
 
 	st := toIfaceSlice(stmts)
-	ex := make([]Executor, len(st))
+	ex := make([]Statement, len(st))
 	for i, v := range st {
-		ex[i] = v.(Executor)
+		ex[i] = v.(Statement)
 	}
 	return StatementsNode{ex}, nil
 }
@@ -77,7 +77,7 @@ func (n StatementsNode) exec() error {
 	return nil
 }
 
-// ReturnNode
+// ReturnNode return value to the caller. 
 type ReturnNode struct {
 	arg IdentifierNode
 }
@@ -90,7 +90,7 @@ func (n ReturnNode) exec() (int, error) {
 	return v, err
 }
 
-// IfNode
+// IfNode controls conditional branching. 
 type IfNode struct {
 	arg        LogicalExpressionNode
 	statements StatementsNode
@@ -111,7 +111,7 @@ func (n IfNode) exec() error {
 	return nil
 }
 
-// AssignmentNode
+// AssignmentNode gives a value to a variable
 type AssignmentNode struct {
 	lvalue string
 	rvalue AdditiveExpressionNode
@@ -129,7 +129,7 @@ func (n AssignmentNode) exec() error {
 	return nil
 }
 
-// LogicalExpressionNode
+// LogicalExpressionNode is a logical expression
 type LogicalExpressionNode struct {
 	expr PrimaryExpressionNode
 }
@@ -143,7 +143,7 @@ func (n LogicalExpressionNode) exec() (bool, error) {
 	return b, err
 }
 
-// AdditiveExpressionNode
+// AdditiveExpressionNode is a additive expression
 type AdditiveExpressionNode struct {
 	arg1 interface{}
 	arg2 PrimaryExpressionNode
@@ -195,7 +195,7 @@ func (n AdditiveExpressionNode) exec() (int, error) {
 	return v, err
 }
 
-// PrimaryExpressionNode
+// PrimaryExpressionNode is a basic element
 type PrimaryExpressionNode struct {
 	arg interface{}
 }
@@ -217,7 +217,7 @@ func (n PrimaryExpressionNode) exec() (int, error) {
 	return v, err
 }
 
-// IntegerNode
+// IntegerNode is a integer number
 type IntegerNode struct {
 	val int
 }
@@ -230,7 +230,7 @@ func (n IntegerNode) exec() (int, error) {
 	return n.val, nil
 }
 
-// IdentifierNode
+// IdentifierNode is a reference to variable
 type IdentifierNode struct {
 	val string
 }

examples/json/json.go

@@ -1360,14 +1360,12 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1723,11 +1721,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 		defer p.out(p.in("parseChoiceExpr"))
 	}
 
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()

examples/json/optimized-grammar/json.go

@@ -1531,14 +1531,12 @@ func (p *parser) cloneState() (state statedict) {
 }
 
 // restore parser current state to the state statedict.
+// every restoreState should applied only one time for every cloned state
 func (p *parser) restoreState(state statedict) {
 	if p.debug {
 		defer p.out(p.in("restoreState"))
 	}
-	p.cur.state = make(statedict)
-	for k, v := range state {
-		p.cur.state[k] = v
-	}
+	p.cur.state = state
 }
 
 // get the slice of bytes from the savepoint start to the current position.
@@ -1894,11 +1892,12 @@ func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) {
 		defer p.out(p.in("parseChoiceExpr"))
 	}
 
-	state := p.cloneState()
 	for altI, alt := range ch.alternatives {
 		// dummy assignment to prevent compile error if optimized
 		_ = altI
 
+		state := p.cloneState()
+
 		p.pushV()
 		val, ok := p.parseExpr(alt)
 		p.popV()