Functional is constructed within parser, not scanner

chunk_ast.go

@@ -33,8 +33,8 @@ type ASTControlTag struct {
 	branches []*ASTControlTag
 }
 
-func (n ASTSeq) String() string {
+func MustYAML(val interface{}) string {
-	b, err := yaml.Marshal(n)
+	b, err := yaml.Marshal(val)
 	if err != nil {
 		panic(err)
 	}

chunk_parser_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -13,16 +14,18 @@ func TestChunkParser(t *testing.T) {
 	},
 	}
 
-	for _, test := range chunkTests {
+	for i, test := range chunkTests {
-		tokens := ScanChunks(test.in, "")
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
-		// fmt.Println(tokens)
+			tokens := ScanChunks(test.in, "")
-		ast, err := Parse(tokens)
+			// fmt.Println(tokens)
-		require.NoError(t, err, test.in)
+			ast, err := Parse(tokens)
-		// fmt.Println("%#v", ast)
+			require.NoErrorf(t, err, test.in)
-		buf := new(bytes.Buffer)
+			// fmt.Println(MustYAML(ast))
-		err = ast.Render(buf, ctx)
+			buf := new(bytes.Buffer)
-		require.NoError(t, err, test.in)
+			err = ast.Render(buf, ctx)
-		require.Equal(t, test.expected, buf.String(), test.in)
+			require.NoErrorf(t, err, test.in)
+			require.Equalf(t, test.expected, buf.String(), test.in)
+		})
 	}
 }
 

expression_parser.y

@@ -6,12 +6,15 @@ import (
 %}
 %union {
    name string
-   val func(Context) interface{}
+   val interface{}
+   f func(Context) interface{}
 }
-%type <val> expr
+%type <f> expr
-%token <val> LITERAL IDENTIFIER
+%token <val> LITERAL
-%token <name> RELATION
+%token <name> IDENTIFIER RELATION
 %%
 top: expr { yylex.(*lexer).val = $1 };
 
-expr: LITERAL | IDENTIFIER;
+expr:
+  LITERAL { $$ = func(_ Context) interface{} { return $1 } }
+| IDENTIFIER { $$ = func(ctx Context) interface{} { return ctx.Variables[$1] } }

scanner.go

@@ -263,18 +263,18 @@ _eof_trans:
 //line scanner.rl:36
  lex.act = 2;
 		case 4:
-//line scanner.rl:56
+//line scanner.rl:55
  lex.act = 4;
 		case 5:
 //line scanner.rl:41
  lex.act = 5;
 		case 6:
-//line scanner.rl:56
+//line scanner.rl:55
  lex.te = ( lex.p)+1
 { tok = RELATION; out.name = string(lex.data[lex.ts:lex.te]); ( lex.p)++; goto _out
  }
 		case 7:
-//line scanner.rl:47
+//line scanner.rl:46
  lex.te = ( lex.p)
 ( lex.p)--
 {
@@ -283,12 +283,12 @@ _eof_trans:
 			if err != nil {
 				panic(err)
 			}
-			out.val = func(_ Context) interface{} { return n }
+			out.val = n
 			( lex.p)++; goto _out
 
 		}
 		case 8:
-//line scanner.rl:56
+//line scanner.rl:55
  lex.te = ( lex.p)
 ( lex.p)--
 { tok = RELATION; out.name = string(lex.data[lex.ts:lex.te]); ( lex.p)++; goto _out
@@ -299,13 +299,12 @@ _eof_trans:
 ( lex.p)--
 {
 			tok = IDENTIFIER
-			name := string(lex.data[lex.ts:lex.te])
+			out.name = string(lex.data[lex.ts:lex.te])
-			out.val = func(ctx Context) interface{} { return ctx.Variables[name] }
 			( lex.p)++; goto _out
 
 		}
 		case 10:
-//line scanner.rl:67
+//line scanner.rl:66
  lex.te = ( lex.p)
 ( lex.p)--
 
@@ -316,8 +315,9 @@ _eof_trans:
 	{( lex.p) = ( lex.te) - 1
 
 			tok = LITERAL
-			val := string(lex.data[lex.ts:lex.te]) == "true"
+			out.val = string(lex.data[lex.ts:lex.te]) == "true"
-			out.val = func(_ Context) interface{} { return val }
+			( lex.p)++; goto _out
+
 		}
 	case 4:
 	{( lex.p) = ( lex.te) - 1
@@ -327,14 +327,13 @@ _eof_trans:
 	{( lex.p) = ( lex.te) - 1
 
 			tok = IDENTIFIER
-			name := string(lex.data[lex.ts:lex.te])
+			out.name = string(lex.data[lex.ts:lex.te])
-			out.val = func(ctx Context) interface{} { return ctx.Variables[name] }
 			( lex.p)++; goto _out
 
 		}
 	}
 	
-//line scanner.go:338
+//line scanner.go:337
 		}
 	}
 
@@ -348,7 +347,7 @@ _again:
 //line NONE:1
  lex.ts = 0
 
-//line scanner.go:352
+//line scanner.go:351
 		}
 	}
 
@@ -370,7 +369,7 @@ _again:
 	_out: {}
 	}
 
-//line scanner.rl:71
+//line scanner.rl:70
 
 
 	return tok

scanner.rl

@@ -35,13 +35,12 @@ func (lex *lexer) Lex(out *yySymType) int {
 	%%{
 		action Bool {
 			tok = LITERAL
-			val := string(lex.data[lex.ts:lex.te]) == "true"
+			out.val = string(lex.data[lex.ts:lex.te]) == "true"
-			out.val = func(_ Context) interface{} { return val }
+			fbreak;
 		}
 		action Ident {
 			tok = IDENTIFIER
-			name := string(lex.data[lex.ts:lex.te])
+			out.name = string(lex.data[lex.ts:lex.te])
-			out.val = func(ctx Context) interface{} { return ctx.Variables[name] }
 			fbreak;
 		}
 		action Number {
@@ -50,7 +49,7 @@ func (lex *lexer) Lex(out *yySymType) int {
 			if err != nil {
 				panic(err)
 			}
-			out.val = func(_ Context) interface{} { return n }
+			out.val = n
 			fbreak;
 		}
 		action Relation { tok = RELATION; out.name = string(lex.data[lex.ts:lex.te]); fbreak; }

y.go

@@ -12,7 +12,8 @@ import (
 type yySymType struct {
 	yys  int
 	name string
-	val  func(Context) interface{}
+	val  interface{}
+	f    func(Context) interface{}
 }
 
 const LITERAL = 57346
@@ -423,9 +424,21 @@ yydefault:
 
 	case 1:
 		yyDollar = yyS[yypt-1 : yypt+1]
-		//line expression_parser.y:15
+		//line expression_parser.y:16
 		{
-			yylex.(*lexer).val = yyDollar[1].val
+			yylex.(*lexer).val = yyDollar[1].f
+		}
+	case 2:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line expression_parser.y:19
+		{
+			yyVAL.f = func(_ Context) interface{} { return yyDollar[1].val }
+		}
+	case 3:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line expression_parser.y:20
+		{
+			yyVAL.f = func(ctx Context) interface{} { return ctx.Variables[yyDollar[1].name] }
 		}
 	}
 	goto yystack /* stack new state and value */