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|
package driver
import (
"fmt"
"strings"
"testing"
"github.com/nihei9/vartan/grammar"
"github.com/nihei9/vartan/spec"
)
func TestParser_Parse(t *testing.T) {
tests := []struct {
specSrc string
src string
specErr bool
}{
{
specSrc: `
expr
: expr "\+" term
| term
;
term
: term "\*" factor
| factor
;
factor
: "\(" expr "\)"
| id
;
id: "[A-Za-z_][0-9A-Za-z_]*";
`,
src: `(a+(b+c))*d+e`,
},
{
specSrc: `
mode_tran_seq
: mode_tran_seq mode_tran
| mode_tran
;
mode_tran
: push_m1
| push_m2
| pop_m1
| pop_m2
;
push_m1: "->" # push m1;
@mode m1
push_m2: "-->" # push m2;
@mode m1
pop_m1 : "<-" # pop;
@mode m2
pop_m2: "<--" # pop;
`,
src: `->--><--<-`,
},
{
specSrc: `
s
: foo bar
;
foo: "foo";
@mode default
bar: "bar";
`,
src: `foobar`,
},
// The parser can skips specified tokens.
{
specSrc: `
s
: foo bar
;
foo: "foo";
bar: "bar";
white_space: "[\u{0009}\u{0020}]+" # skip;
`,
src: `foo bar`,
},
// A grammar can contain fragments.
{
specSrc: `
s
: tagline
;
tagline: "\f{words} IS OUT THERE.";
fragment words: "[A-Za-z\u{0020}]+";
`,
src: `THE TRUTH IS OUT THERE.`,
},
// A grammar can contain ast actions.
{
specSrc: `
list
: "\[" elems "]" # ast '(list $2...)
;
elems
: elems "," id # ast '(elems $1... $3)
| id
;
whitespace: "\u{0020}+" # skip;
id: "[A-Za-z]+";
`,
src: `[Byers, Frohike, Langly]`,
},
// The first element of a tree structure must be the same ID as an LHS of a production.
{
specSrc: `
s
: foo # ast '(start $1)
;
foo
: bar
;
bar: "bar";
`,
specErr: true,
},
// An ast action cannot be applied to a terminal symbol.
{
specSrc: `
s
: "foo" # ast '(s $1...)
;
`,
specErr: true,
},
// The expansion cannot be applied to a terminal symbol.
{
specSrc: `
s
: foo # ast '(s $1...)
;
foo: "foo";
`,
specErr: true,
},
}
for i, tt := range tests {
t.Run(fmt.Sprintf("#%v", i), func(t *testing.T) {
ast, err := spec.Parse(strings.NewReader(tt.specSrc))
if err != nil {
t.Fatal(err)
}
g, err := grammar.NewGrammar(ast)
if tt.specErr {
if err == nil {
t.Fatal("an expected error didn't occur")
}
fmt.Printf("error: %v\n", err)
return
} else {
if err != nil {
t.Fatal(err)
}
}
gram, err := grammar.Compile(g)
if err != nil {
t.Fatal(err)
}
p, err := NewParser(gram, strings.NewReader(tt.src))
if err != nil {
t.Fatal(err)
}
err = p.Parse()
if err != nil {
t.Fatal(err)
}
fmt.Println("CST:")
PrintTree(p.CST(), 0)
fmt.Println("AST:")
PrintTree(p.AST(), 0)
})
}
}
|
