Hacking; added basic tests and if/let/fn special forms

Author: davehughes

Makefile

@@ -1,5 +1,6 @@
 .PHONY: bootstrap build-parser watch
 
+GRAMMARFILE=grammar.peg
 PARSERFILE=lang/parser.go
 SAMPLEFILE=samples/sample1.clj
 
@@ -9,12 +10,15 @@ bootstrap:
 	go get -u github.com/cespare/reflex
 
 watch:
-	reflex --inverse-glob=$(PARSERFILE) -- $(MAKE) test-parser
+	reflex --inverse-glob=$(PARSERFILE) -- $(MAKE) test
 
-build-parser:
-	echo "package lang" > $(PARSERFILE)
-	pigeon <grammar.peg | gofmt >>$(PARSERFILE)
+$(PARSERFILE): $(GRAMMARFILE)
+	@echo "== Rebuilding parser"
+	echo "package lang" > $@
+	pigeon <$< | gofmt >>$@
 
-test-parser: build-parser
-	go run main.go $(SAMPLEFILE)
+build-parser: $(PARSERFILE)
 
+test: $(PARSERFILE)
+	@echo "== Running unit tests"
+	go test ./...

glide.lock

@@ -2,3 +2,5 @@ package: github.com/davehughes/lparse
 import:
 - package: github.com/pkg/errors
   version: ^0.8.0
+- package: github.com/stretchr/testify
+  version: ^1.1.4

glide.yaml

@@ -9,10 +9,10 @@ Input <- forms:Form* EOF {
 }
 
 Form <- _ form:( LineComment / List / Lambda / Vector / Set / Map / 
-            QuotedForm / Numeric / Symbol / Keyword / String
+            QuotedForm / AtomDeref / Numeric / Symbol / Keyword / String
             ) _ {
-    fmt.Printf("Form: %v\n", form) 
-    return string(c.text), nil
+    // fmt.Printf("Form: %v\n", form) 
+    return form, nil
 }
 
 EOF = !.
@@ -24,46 +24,56 @@ LineComment <- _? ';' comment:[^\r\n]* {
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
         Value: fmt.Sprint(comment),
         }, nil
-    /* return showComponent("commented-line", c.text) */
 }
 
 List <- '(' forms:Form* ')' {
-    return &Collection{
+    return &List{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Type: CollectionList,
-        Items: forms.([]interface{}),
+        Forms: forms.([]interface{}),
         }, nil
 }
 
 Vector <- '[' forms:Form* ']' {
-    return &Collection{
+    return &Vector{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Type: CollectionVector,
-        Items: forms.([]interface{}),
+        Forms: forms.([]interface{}),
         }, nil
 }
 
 Map <- '{' forms:Form* '}' {
-    return &Collection{
+    numForms := len(forms.([]interface{}))
+    if numForms % 2 != 0 {
+        return nil, ErrOddNumberOfMapForms
+    }
+    return &Map{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Type: CollectionMap,
-        Items: forms.([]interface{}),
+        Forms: forms.([]interface{}),
         }, nil
 }
 
-Set <- '#' '{' forms:Form '}' {
-    return &Collection{
+Set <- '#' '{' forms:Form* '}' {
+    return &Set{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Type: CollectionSet,
-        Items: forms.([]interface{}),
+        Forms: forms.([]interface{}),
         }, nil
 }
 
 Lambda <- '#' '(' forms:Form* ')' {
-    return &Collection{
+    return &Lambda{
+        Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
+        Forms: forms.([]interface{}),
+    }, nil
+}
+
+AtomDeref <- "@" form:Form {
+    return &List{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Type: CollectionLambda,
-        Items: forms.([]interface{}),
+        Forms: []interface{}{
+            &Symbol{
+                Name: "deref",
+            },
+            form,
+        },
     }, nil
 }
 
@@ -72,29 +82,44 @@ Keyword <- ( NamespacedKeyword / BareKeyword)
 NamespacedKeyword <- ':' ':' sym:Symbol {
     return &Keyword{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Name: fmt.Sprint(sym),
+        Name: (sym.(*Symbol)).Name,
         Namespace: "TODO: namespaced",
     }, nil
 }
 
 BareKeyword <- ':' sym:Symbol {
     return &Keyword{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Name: fmt.Sprint(sym),
+        Name: (sym.(*Symbol)).Name,
     }, nil
 }
 
 Symbol <- [a-z0-9-+*?!&^%#?<>%/\\]i+ {
-    return &Symbol{
-        Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Name: string(c.text),
-    }, nil
+    pos := Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset}
+    switch string(c.text) {
+    case "nil":
+        return &Nil{Position: pos}, nil
+    case "true":
+        return &True{Position: pos}, nil
+    case "false":
+        return &False{Position: pos}, nil
+    default:
+        return &Symbol{
+            Position: pos,
+            Name: string(c.text),
+        }, nil
+    }
 }
 
 QuotedForm <- ( "'" ) form:Form {
-    return &QuotedForm{
+    return &List{
         Position: Position{Line: c.pos.line, Column: c.pos.col, Offset: c.pos.offset},
-        Form: form,
+        Forms: []interface{}{
+            &Symbol{
+                Name: "quote",
+            },
+            form,
+        },
     }, nil
 }
 

grammar.peg

@@ -14,11 +14,19 @@ type Keyword struct {
 	Namespace string
 }
 
+func (s Keyword) String() string {
+	return fmt.Sprintf("(keyword %v)", s.Name)
+}
+
 type Symbol struct {
 	Position
 	Name string
 }
 
+func (s Symbol) String() string {
+	return fmt.Sprintf("(symbol %v)", s.Name)
+}
+
 type String struct {
 	Position
 	Value string
@@ -39,22 +47,17 @@ type Position struct {
 	Offset int
 }
 
-type CollectionType int
-
-const (
-	CollectionList CollectionType = iota
-	CollectionVector
-	CollectionMap
-	CollectionSet
-	CollectionLambda
-)
-
-type Collection struct {
+type Container struct {
 	Position
-	Type  CollectionType
-	Items []interface{}
+	Forms []interface{}
 }
 
+type List Container
+type Vector Container
+type Map Container
+type Set Container
+type Lambda Container
+
 type Integer struct {
 	Position
 	ParsedValue string
@@ -67,7 +70,10 @@ type Float struct {
 	Value       float64
 }
 
-type QuotedForm struct {
+type ReservedWord struct {
 	Position
-	Form interface{}
 }
+
+type Nil ReservedWord
+type True ReservedWord
+type False ReservedWord

lang/ast.go

@@ -0,0 +1,13 @@
+package lang
+
+import "github.com/pkg/errors"
+
+var (
+	ErrNotImplemented          = errors.New("Not implemented")
+	ErrOddNumberOfMapForms     = errors.New("Map literal must contain an even number of forms")
+	ErrIfTooFewArgs            = errors.New("Too few args to if")
+	ErrIfTooManyArgs           = errors.New("Too many args to if")
+	ErrUnresolvedSymbol        = errors.New("Unable to resolve symbol")
+	ErrOddNumberOfBindingForms = errors.New("Binding vector must have an even number of forms")
+	ErrUnrecognizedBindingForm = errors.New("Unrecognized binding form")
+)