added ast parsing

packages/boringlang/src/parse/grammar.ts

@@ -0,0 +1,66 @@
+import * as ohm from "ohm-js";
+
+export const boringGrammar = ohm.grammar(String.raw`
+  Boringlang {
+    ReturnStatement       = "return" Expression ";"
+    LetStatement          = "let" Identifier (":" TypeUsage)? "=" Expression ";"
+    AssignmentStatement   = VariableUsage "=" Expression ";"
+                          | StructGetter "=" Expression ";"
+    ExpressionStatement   = Expression ";"
+    Statement             = ExpressionStatement
+                          | LetStatement
+                          | ReturnStatement
+                          | AssignmentStatement
+    LiteralInt            = digit+
+    LiteralFloat          = digit* "." digit+
+    LiteralBool           = "true" | "false"
+    LiteralString         = "\"" (~"\"" any)* "\""
+                          | "'" (~"'" any)* "'"
+    LiteralStructField    = Identifier ":" Expression
+    LiteralStruct         = Identifier "{" ListOf<LiteralStructField, ","> "}"
+    Identifier            = (letter | "_")+ (letter | digit | "_")*
+    FunctionCall          = Expression "(" ListOf<Expression, ","> ")"
+    StructGetter          = Expression "." Identifier
+    VariableUsage         = Identifier
+    IfExpression          = "if" "(" Expression ")" Block ("else" Block)?
+    Term                  = LiteralInt
+                          | LiteralFloat
+                          | LiteralBool
+                          | LiteralString
+                          | LiteralStruct
+                          | IfExpression
+                          | Block
+                          | "(" Expression ")" -- parens
+                          | VariableUsage
+    Factor                = Factor "*" Term -- mult
+                          | Factor "/" Term -- div
+                          | Term
+    Expression            = Expression "+" Factor -- plus
+                          | Expression "-" Factor -- minus
+                          | StructGetter
+                          | FunctionCall
+                          | Factor
+    Block                 = "{" Statement* Expression? "}"
+    NamedTypeUsage        = Identifier
+    TypeUsage             = NamedTypeUsage
+                          | "fn" "(" ListOf<TypeUsage, ","> ")" ":" TypeUsage -- function_tu
+    FunctionArgument      = Identifier ":" TypeUsage
+    FunctionDeclaration   = "fn" Identifier "(" ListOf<FunctionArgument, ","> ")" ":" TypeUsage
+    Function              = FunctionDeclaration Block
+    StructTypeField       = Identifier ":" TypeUsage
+    StructTypeDeclaration = "type" Identifier "struct" "{" ListOf<StructTypeField, ","> "}"
+    TraitMethod           = FunctionDeclaration ";"
+    TraitTypeDeclaration  = "type" Identifier "trait" "{" TraitMethod* "}"
+    TypeDeclaration       = StructTypeDeclaration
+                          | TraitTypeDeclaration
+    Impl                  = "impl" (NamedTypeUsage "for")? NamedTypeUsage "{" Function* "}"
+    ModuleItem            = Function
+                          | TypeDeclaration
+                          | Impl
+    Module                = ModuleItem*
+
+    lineTerminator        = "\n" | "\r" | "\u2028" | "\u2029"
+    comment               = "//" (~lineTerminator any)* lineTerminator
+    space                += comment
+  }
+`);