/// <summary>
/// A string -> bool function for determining whether a string has content.
/// </summary>
public static string EnsureHasChars(this PfaContext ctx)
{
Contracts.CheckValue(ctx, nameof(ctx));
const string name = "hasChars";
if (ctx.ContainsFunc(name))
{
return("u." + name);
}
ctx.AddFunc(name, new JArray(Param("str", Type.String)), Type.Bool,
Call(">", Call("s.len", "str"), 0));
return("u." + name);
}
/// <summary>
/// This ensures that there is a function formatted as "count_type" (for example, "count_double"),
/// that takes either a map or array and returns the number of items in that map or array.
/// </summary>
/// <param name="ctx">The context to check for the existence of this</param>
/// <param name="itemType">The item type this will operate on</param>
public static string EnsureCount(this PfaContext ctx, JToken itemType)
{
Contracts.CheckValue(ctx, nameof(ctx));
Contracts.CheckValue(itemType, nameof(itemType));
var name = "count_" + itemType.ToString();
if (ctx.ContainsFunc(name))
{
return("u." + name);
}
ctx.AddFunc(name, new JArray(Param("a", Type.Vector(itemType))), Type.Int,
VectorCase(itemType, "a", "ma", Call("map.len", "ma"), "aa", Call("a.len", "aa")));
return("u." + name);
}
private static string EnsureOpCore(PfaContext ctx, string funcPrefix, string binOp, JToken itemType, JToken returnType = null)
{
Contracts.CheckValue(ctx, nameof(ctx));
Contracts.AssertNonEmpty(funcPrefix);
Contracts.AssertNonEmpty(binOp);
Contracts.CheckValue(itemType, nameof(itemType));
Contracts.CheckValueOrNull(returnType);
returnType = returnType ?? itemType;
var name = funcPrefix + "_" + itemType.ToString();
if (ctx.ContainsFunc(name))
{
return("u." + name);
}
ctx.AddFunc(name, new JArray(Param("a", itemType), Param("b", itemType)), returnType, Call(binOp, "a", "b"));
return("u." + name);
}
