1 files changed, 149 insertions, 0 deletions
diff --git a/src/symtable.zig b/src/symtable.zig
new file mode 100644
index 0000000..0ff8fc8
--- /dev/null
+++ b/src/symtable.zig
@@ -0,0 +1,149 @@
+const std = @import("std");
+const pars = @import("parser.zig");
+
+const Scope = struct {
+    par: ?*Scope,
+    symbs: std.StringHashMap(Symbol),
+};
+
+const Symbol = union(enum) {
+    Type: SymbType,
+    Value: SymbValue,
+};
+
+pub const SymbType = union(enum) {
+    Void,
+    Integer,
+    String,
+};
+
+const SymbValue = struct {
+    typ: SymbType,
+    id: u32,
+    mut: bool,
+};
+
+pub const SymbolTable = struct {
+    scope: ?*Scope = null,
+    allocator: std.mem.Allocator,
+
+    pub fn init(allocator: std.mem.Allocator) !*SymbolTable {
+        const scope = try allocator.create(Scope);
+        scope.par = null;
+        scope.symbs = std.StringHashMap(Symbol).init(allocator);
+        const table = try allocator.create(SymbolTable);
+        table.* = SymbolTable{
+            .scope = scope,
+            .allocator = allocator,
+        };
+        return table;
+    }
+
+    pub fn deinit(self: *SymbolTable) void {
+        if (self.scope) |scope| {
+            scope.symbs.deinit();
+            self.allocator.destroy(scope);
+        }
+    }
+
+    pub fn makeChild(self: *SymbolTable) SymbolTable {
+        const scope = try self.allocator.create(Scope);
+        scope.par = self;
+        scope.symbs = std.StringHashMap(Symbol).init(self.allocator);
+        return SymbolTable{
+            .scope = scope,
+            .allocator = self.allocator,
+        };
+    }
+
+    pub fn parent(self: SymbolTable) ?*SymbolTable {
+        if (self.scope) |scope|
+            if (scope.par) |par|
+                return par;
+        return null;
+    }
+
+    pub fn contains(self: SymbolTable, ident: []const u8) bool {
+        if (self.scope) |scope| return scope.symbs.contains(ident);
+        return false;
+    }
+
+    pub fn get(self: SymbolTable, ident: []const u8) ?Symbol {
+        if (self.scope) |scope| return scope.symbs.get(ident);
+        return null;
+    }
+
+    pub fn getValue(self: SymbolTable, ident: []const u8) ?SymbValue {
+        if (self.get(ident)) |symbol|
+            return switch (symbol) {
+                .Value => |value| value,
+                else => null,
+            };
+
+        return null;
+    }
+
+    pub fn getMut(self: *SymbolTable, ident: []const u8) ?Symbol {
+        if (self.get(ident)) |symbol|
+            return switch (symbol) {
+                .Value => null,
+                else => symbol,
+            };
+        return null;
+    }
+
+    pub fn insert(self: *SymbolTable, ident: []const u8, symbol: Symbol) bool {
+        if (self.scope) |scope| {
+            if (scope.symbs.getEntry(ident)) return false;
+            scope.symbs.put(ident, symbol);
+            return true;
+        }
+        return false;
+    }
+};
+
+const Populator = struct {
+    id: u32,
+    allocator: std.mem.Allocator,
+
+    pub fn init(allocator: std.mem.Allocator) Populator {
+        return .{
+            .id = 0,
+            .allocator = allocator,
+        };
+    }
+
+    fn populateSymtable(self: *Populator, node: *pars.Node) void {
+        switch (node) {
+            .Stmt => |stmt| {
+                const table: *SymbolTable = stmt.symtable;
+                switch (stmt.kind) {
+                    .defVar => |variable| {
+                        const symbol = self.buildValueSymb(
+                            table,
+                            if (variable.expr.typ) |typ| typ else .Integer,
+                            true,
+                        );
+                        table.insert(variable.ident, symbol);
+                    },
+                    .defValue => |value| {
+                        const symbol = self.buildValueSymb(
+                            table,
+                            if (value.expr.typ) |typ| typ else .Integer,
+                            true,
+                        );
+                        table.insert(value.ident, symbol);
+                    },
+                }
+            },
+            else => {
+                for (node.children(self.allocator)) |child|
+                    populateSymtable(&child);
+            },
+        }
+    }
+
+    fn buildValueSymb(self: *Populator, table: *SymbolTable, typ: SymbType, mutable: bool) Symbol {
+        const newTyp = table.getType(typ);
+    }
+};