feat(parser): switch over to the new parser (#352)

There are a few notable differences.

First, true and false are not reserved identifiers so they will evaluate
as identifiers. It is up to the caller to set the value for these
predeclared identifiers. This is done manually in one test and otherwise
it is done automatically in the interpreter.

Second, some of the location information changed. Notably, object
expressions start at the `{` symbol instead of the location of the first
property and call expression start at the beginning of the callee
instead of the first parenthesis. This second one is identical to what
the go parser does. The type inference tests had to be modified for this
reason.

The parser options have been removed. They seem to have been
automatically generated by pigeon and weren't applicable anymore. This
changes the type signature, but it doesn't change how it is called in a
majority of situations.

The pigeon dependency has been removed as it is no longer needed.

Makefile

@@ -11,7 +11,7 @@
 #    * All recursive Makefiles must support the targets: all and clean.
 #
 
-SUBDIRS = ast parser internal/scanner
+SUBDIRS = ast internal/scanner
 
 GO_ARGS=-tags '$(GO_TAGS)'
 
@@ -25,7 +25,6 @@ export GO_VET=env GO111MODULE=on go vet $(GO_ARGS)
 
 # List of utilities to build as part of the build process
 UTILS := \
-	bin/$(GOOS)/pigeon \
 	bin/$(GOOS)/cmpgen
 
 all: $(UTILS) $(SUBDIRS)
@@ -36,9 +35,6 @@ $(SUBDIRS): $(UTILS)
 clean: $(SUBDIRS)
 	rm -rf bin
 
-bin/$(GOOS)/pigeon: go.mod go.sum
-	$(GO_BUILD) -o $@ github.com/mna/pigeon
-
 bin/$(GOOS)/cmpgen: ./ast/asttest/cmpgen/main.go
 	$(GO_BUILD) -o $@ ./ast/asttest/cmpgen
 

go.mod

@@ -18,7 +18,6 @@ require (
 	github.com/mattn/go-runewidth v0.0.3 // indirect
 	github.com/mattn/go-tty v0.0.0-20180907095812-13ff1204f104 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
-	github.com/mna/pigeon v1.0.1-0.20180808201053-bb0192cfc2ae
 	github.com/opentracing/opentracing-go v1.0.2
 	github.com/pierrec/lz4 v2.0.5+incompatible // indirect
 	github.com/pkg/errors v0.8.0
@@ -39,7 +38,6 @@ require (
 	golang.org/x/net v0.0.0-20181011144130-49bb7cea24b1 // indirect
 	golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f // indirect
 	golang.org/x/sys v0.0.0-20181011152604-fa43e7bc11ba // indirect
-	golang.org/x/tools v0.0.0-20181121193951-91f80e683c10 // indirect
 	gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca
 	google.golang.org/appengine v1.2.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect

go.sum

@@ -39,8 +39,6 @@ github.com/mattn/go-tty v0.0.0-20180907095812-13ff1204f104 h1:d8RFOZ2IiFtFWBcKEH
 github.com/mattn/go-tty v0.0.0-20180907095812-13ff1204f104/go.mod h1:XPvLUNfbS4fJH25nqRHfWLMa1ONC8Amw+mIA639KxkE=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
-github.com/mna/pigeon v1.0.1-0.20180808201053-bb0192cfc2ae h1:mQO+oxi0kpii/TX+ltfTCFuYkOjEn53JhaOObiMuvnk=
-github.com/mna/pigeon v1.0.1-0.20180808201053-bb0192cfc2ae/go.mod h1:Iym28+kJVnC1hfQvv5MUtI6AiFFzvQjHcvI4RFTG/04=
 github.com/opentracing/opentracing-go v1.0.2 h1:3jA2P6O1F9UOrWVpwrIo17pu01KWvNWg4X946/Y5Zwg=
 github.com/opentracing/opentracing-go v1.0.2/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/pierrec/lz4 v2.0.5+incompatible h1:2xWsjqPFWcplujydGg4WmhC/6fZqK42wMM8aXeqhl0I=
@@ -93,8 +91,6 @@ golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180525024113-a5b4c53f6e8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20181121193951-91f80e683c10 h1:6aZMfwu0xab6imbp0uu++D3WXR+p0+RDYOqqb0uY8KU=
-golang.org/x/tools v0.0.0-20181121193951-91f80e683c10/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca h1:PupagGYwj8+I4ubCxcmcBRk3VlUWtTg5huQpZR9flmE=
 gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca/go.mod h1:Y+Yx5eoAFn32cQvJDxZx5Dpnq+c3wtXuadVZAcxbbBo=
 gonum.org/v1/netlib v0.0.0-20181029234149-ec6d1f5cefe6 h1:4WsZyVtkthqrHTbDCJfiTs8IWNYE4uvsSDgaV6xpp+o=

internal/parser/parser_test.go

@@ -438,6 +438,28 @@ func testParser(runFn func(name string, fn func(t testing.TB))) {
 				},
 			},
 		},
+		{
+			name: "declare variable as an empty array",
+			raw:  `howdy = []`,
+			want: &ast.Program{
+				BaseNode: base("1:1", "1:11"),
+				Body: []ast.Statement{
+					&ast.VariableDeclaration{
+						BaseNode: base("1:1", "1:11"),
+						Declarations: []*ast.VariableDeclarator{{
+							BaseNode: base("1:1", "1:11"),
+							ID: &ast.Identifier{
+								BaseNode: base("1:1", "1:6"),
+								Name:     "howdy",
+							},
+							Init: &ast.ArrayExpression{
+								BaseNode: base("1:9", "1:11"),
+							},
+						}},
+					},
+				},
+			},
+		},
 		{
 			name: "use variable to declare something",
 			raw: `howdy = 1

interpreter/interpreter.go

@@ -10,6 +10,11 @@ import (
 	"github.com/pkg/errors"
 )
 
+var topScope = NewScopeWithValues(map[string]values.Value{
+	"true":  values.NewBool(true),
+	"false": values.NewBool(false),
+})
+
 // Interpreter used to interpret a Flux program
 type Interpreter struct {
 	values  []values.Value
@@ -21,7 +26,7 @@ type Interpreter struct {
 // NewInterpreter instantiates a new Flux Interpreter whose builtin values are not mutable.
 // Options are always mutable.
 func NewInterpreter(options, builtins map[string]values.Value, types *TypeScope) *Interpreter {
-	optionScope := NewScopeWithValues(options)
+	optionScope := topScope.NestWithValues(options)
 	globalScope := optionScope.NestWithValues(builtins)
 	interpreter := &Interpreter{
 		options: optionScope,
@@ -34,7 +39,7 @@ func NewInterpreter(options, builtins map[string]values.Value, types *TypeScope)
 // NewMutableInterpreter instantiates a new Flux Interpreter whose builtin values are mutable.
 // Options are always mutable.
 func NewMutableInterpreter(options, builtins map[string]values.Value, types *TypeScope) *Interpreter {
-	optionScope := NewScopeWithValues(options)
+	optionScope := topScope.NestWithValues(options)
 	globalScope := optionScope.NestWithValues(builtins)
 	interpreter := &Interpreter{
 		options: optionScope,