Implemented array storage

src/build/expression/Expression_test.go

@@ -79,6 +79,10 @@ func TestParse(t *testing.T) {
 		{"Function calls 27", "sum(a,b)*2+15*4", "(+ (* (λ sum a b) 2) (* 15 4))"},
 		{"Package function calls", "math.sum(a,b)", "(λ (. math sum) a b)"},
 		{"Package function calls 2", "generic.math.sum(a,b)", "(λ (. (. generic math) sum) a b)"},
+		{"Array access", "a[0]", "(@ a 0)"},
+		{"Array access 2", "a[b+c]", "(@ a (+ b c))"},
+		{"Array access 3", "a.b[c]", "(@ (. a b) c)"},
+		{"Array access 4", "a.b[c+d]", "(@ (. a b) (+ c d))"},
 	}
 
 	for _, test := range tests {

src/build/expression/Operator.go

@@ -18,6 +18,7 @@ type Operator struct {
 var Operators = map[string]*Operator{
 	".":  {".", 13, 2},
 	"λ":  {"λ", 12, 1},
+	"@":  {"@", 12, 2},
 	"!":  {"!", 11, 1},
 	"*":  {"*", 10, 2},
 	"/":  {"/", 10, 2},

src/build/expression/Parse.go

@@ -6,7 +6,10 @@ import (
 	"git.akyoto.dev/cli/q/src/build/token"
 )
 
-var call = []byte("λ")
+var (
+	call  = []byte("λ")
+	array = []byte("@")
+)
 
 // Parse generates an expression tree from tokens.
 func Parse(tokens token.List) *Expression {
@@ -18,7 +21,7 @@ func Parse(tokens token.List) *Expression {
 	)
 
 	for i, t := range tokens {
-		if t.Kind == token.GroupStart {
+		if t.Kind == token.GroupStart || t.Kind == token.ArrayStart {
 			groupLevel++
 
 			if groupLevel == 1 {
@@ -28,23 +31,30 @@ func Parse(tokens token.List) *Expression {
 			continue
 		}
 
-		if t.Kind == token.GroupEnd {
+		if t.Kind == token.GroupEnd || t.Kind == token.ArrayEnd {
 			groupLevel--
 
 			if groupLevel != 0 {
 				continue
 			}
 
-			isFunctionCall := isComplete(cursor)
-
-			if isFunctionCall {
+			// Function call or array access
+			if isComplete(cursor) {
 				parameters := NewList(tokens[groupPosition:i])
 
 				node := New()
 				node.Token.Kind = token.Operator
 				node.Token.Position = tokens[groupPosition].Position
-				node.Token.Bytes = call
-				node.Precedence = precedence("λ")
+
+				switch t.Kind {
+				case token.GroupEnd:
+					node.Token.Bytes = call
+					node.Precedence = precedence("λ")
+
+				case token.ArrayEnd:
+					node.Token.Bytes = array
+					node.Precedence = precedence("@")
+				}
 
 				if cursor.Token.Kind == token.Operator && node.Precedence > cursor.Precedence {
 					cursor.LastChild().Replace(node)