parser: implement support for var declarations

The full Go syntax is supported, blocks or line,
mutiple comma separated variables, assignments.
In local and global frame.

1 files changed, 57 insertions, 0 deletions

diff --git a/parser/tokens.go b/parser/tokens.go
new file mode 100644
index 0000000..acffe58
--- /dev/null
+++ b/parser/tokens.go
@@ -0,0 +1,57 @@
+package parser
+
+import (
+	"fmt"
+
+	"github.com/gnolang/parscan/lang"
+	"github.com/gnolang/parscan/scanner"
+)
+
+type Tokens []scanner.Token
+
+func (toks Tokens) String() (s string) {
+	for _, t := range toks {
+		s += fmt.Sprintf("%#v ", t.Str)
+	}
+	return s
+}
+
+func (toks Tokens) Index(id lang.TokenId) int {
+	for i, t := range toks {
+		if t.Id == id {
+			return i
+		}
+	}
+	return -1
+}
+
+func (toks Tokens) LastIndex(id lang.TokenId) int {
+	for i := len(toks) - 1; i >= 0; i-- {
+		if toks[i].Id == id {
+			return i
+		}
+	}
+	return -1
+}
+
+func (toks Tokens) Split(id lang.TokenId) (result []Tokens) {
+	for {
+		i := toks.Index(id)
+		if i < 0 {
+			return append(result, toks)
+		}
+		result = append(result, toks[:i])
+		toks = toks[i+1:]
+	}
+}
+
+func (toks Tokens) SplitStart(id lang.TokenId) (result []Tokens) {
+	for {
+		i := toks[1:].Index(id)
+		if i < 0 {
+			return append(result, toks)
+		}
+		result = append(result, toks[:i])
+		toks = toks[i+1:]
+	}
+}